Past 11 days... average consumption 6.55 kWh/day, of which 1.36 was used by the new fridge. 32% of our consumption was supplied directly from our solar panels (just over 2 kWh/day) while another 2.64kWh was exported to the grid each day.
As a result of the low consumption and strong sunlight, we are now in negative territory for energy costs over the past 102 days (not counting the fixed service fees). The credit for our exported energy will exceed the charge for imported energy by about $2.
We've also had heaps of rain, so the tanks have been full almost constantly for the past six weeks or so.
Friday 12 December 2008
Friday 5 December 2008
More garden photos
This rain and warmth is amazing for plant growth.
Too much effort to embed images in here when you can click and see them all over at my gallery.
Some of them you'd have seen before but there are new ones:
- beans growing beautifully and just today poking out of the cage
- pots where we planted tomatoes and got some volunteer cucumbers or something
- passionfruit vine from the neighbour's place going nuts on our chook pen
- first ever mangoes on a tree planted by a previous resident
- what we think is an avocado that I lopped off ages ago due to disease, regrowing
- tomato bush which "died" with some kind of wilt suddenly springing back to life
Too much effort to embed images in here when you can click and see them all over at my gallery.
Some of them you'd have seen before but there are new ones:
- beans growing beautifully and just today poking out of the cage
- pots where we planted tomatoes and got some volunteer cucumbers or something
- passionfruit vine from the neighbour's place going nuts on our chook pen
- first ever mangoes on a tree planted by a previous resident
- what we think is an avocado that I lopped off ages ago due to disease, regrowing
- tomato bush which "died" with some kind of wilt suddenly springing back to life
Monday 1 December 2008
Quick stats
It's been a great week on the electricity front. Household consumption was 6.86kWh/day. The new fridge has averaged 1.3kWh/day, about a 35% improvement over the old one.
Excluding fixed monthly service fees but including the solar feed-in tariff, our electricity costs for the past 91 days are, in total, $2.62. That's less than three cents a day.
Excluding fixed monthly service fees but including the solar feed-in tariff, our electricity costs for the past 91 days are, in total, $2.62. That's less than three cents a day.
Monday 24 November 2008
Stats Update
Initial figures from the meter attached to the fridge are good. Including the initial cooling effort required after turning it on for the first time, it's averaged about 1.4kWh per day over the past four days. I've reset the meter this morning to correspond with reading all the other meters so I'll be able to build up a better picture of it over time.
The other energy figures are also good. For the past 39 days:
- PV generation up to 4.62 kWh/day
- Household consumption down to 7.88 kWh/day
- Export up to 2.26 kWh/day
We've had more than enough rain recently so the tanks are still supplying water for laundry, toilet and gardening. Hot water system needed boosting one evening during the rainy period but is otherwise cracking along in the spring sunshine. Our recent rates notice showed us maintaining a significantly lower consumption than our neighbours and so I haven't bothered keeping a close eye on the water meter.
The other energy figures are also good. For the past 39 days:
- PV generation up to 4.62 kWh/day
- Household consumption down to 7.88 kWh/day
- Export up to 2.26 kWh/day
We've had more than enough rain recently so the tanks are still supplying water for laundry, toilet and gardening. Hot water system needed boosting one evening during the rainy period but is otherwise cracking along in the spring sunshine. Our recent rates notice showed us maintaining a significantly lower consumption than our neighbours and so I haven't bothered keeping a close eye on the water meter.
Thursday 20 November 2008
Chillin'
Remember how pleased I was when our old electric hot water system died last year? Well I have more wonderful news to share: the fridge, which at 2kWh/day accounts for almost a quarter of all energy used in our home, has also reached the end of the line. Hooray!
Its ability to actually cool things, let alone freeze them, has been deteriorating over time. I recently replaced the seal on the freezer to stop a quite noticeable cold air leak but it really made no difference. The appliance wizard (that's what he called himself) only took a couple of minutes to diagnose a failing compressor.
Decision time. Replacing the compressor would make it cold again, but cost about half of what we paid for the fridge a decade ago. It wouldn't improve the energy-efficiency of the design. It wouldn't fix the broken shelf mount or the cracked door hinge. And it wouldn't give us the extra freezer space Michelle desperately wanted. Maybe it's time for a replacement.
Had heard great things about the efficiency of chest freezers. Actually, the really interesting idea involves converting chest freezers to chest fridges. Good insulation and a lid that opens on the top instead of the side makes for minimal loss of "coolth". However, there's no way a chest fridge was going to be acceptable in our kitchen - space issues, access issues, etc - but maybe we could use a chest freezer in the laundry.
Had also seen a standalone fridge (no freezer compartment) at a school, with an energy star rating that quite impressed me. Maybe one of those for the kitchen. Time to do some research.
The most efficient chest freezers on the Aussie market, according to the official figures, are Denmark-made Vestfrost units - the same brand modified to be a fridge in the earlier link. They have one model which is about the size Michelle would like, 250L, that's rated at a quite frugal 237kWh/year. Would have been a candidate if they weren't so physically large and surprisingly expensive. And imported from the other side of the planet.
Mid-sized efficient freezer options beyond that are surprisingly limited. We quickly narrowed it down to two: a 160L Fisher & Paykel chest rated at 307kWh/year, or a 180L Westinghouse upright freezer rated at 297kWh/year. Westinghouse looks better for us other than being imported from China. So what about the fridge?
Given our simple criteria, there was no contest. Absolutely hands-down, the winner is a brand-new model from Electrolux. A 400L upright single-door fridge that uses just 250kWh/year and it's made here in Australia. This product has the highest energy efficiency score of all 3000 refrigeration units in the database, bar none (it'd score 8 stars, but the ratings only go to six). Price is middle-of-the-range: more than the Asian products and less than the European.
So that was the plan. The Electrolux fridge and the Westinghouse freezer. Combined rated total of 547kWh/year, which is just a smidge under 1.5kWh/day.
Er, hang on. I'm going to spend a couple thousand dollars on the most energy-efficient appliances I can find and still only cut my power consumption by 25%? Admittedly I'd have room for a bit more ice cream... but... only 25%? There's gotta be a better option.
Turns out there is, if I can live with just a single six-pack in the fridge at any one time. Another member of the new Electrolux range is a fairly conventional-looking bottom-mount fridge/freezer. 359L fridge space, 156 in the freezer (more than our old one), and a rated energy use of 428kWh/year. That's good enough for a five-star badge, and it's made right here down under.
So I saved myself a few hundred bucks and improved my energy reduction from 25% to over 40% (based on rated consumption of the new fridge vs actual consumption of the one I had). The fridge was delivered today. Now all I have to do is convince Michelle that going from 120L to 156L really is a significant improvement in freezer capacity and we didn't really need a separate freezer anyway.
Yeah. Wish me luck.
Its ability to actually cool things, let alone freeze them, has been deteriorating over time. I recently replaced the seal on the freezer to stop a quite noticeable cold air leak but it really made no difference. The appliance wizard (that's what he called himself) only took a couple of minutes to diagnose a failing compressor.
Decision time. Replacing the compressor would make it cold again, but cost about half of what we paid for the fridge a decade ago. It wouldn't improve the energy-efficiency of the design. It wouldn't fix the broken shelf mount or the cracked door hinge. And it wouldn't give us the extra freezer space Michelle desperately wanted. Maybe it's time for a replacement.
Had heard great things about the efficiency of chest freezers. Actually, the really interesting idea involves converting chest freezers to chest fridges. Good insulation and a lid that opens on the top instead of the side makes for minimal loss of "coolth". However, there's no way a chest fridge was going to be acceptable in our kitchen - space issues, access issues, etc - but maybe we could use a chest freezer in the laundry.
Had also seen a standalone fridge (no freezer compartment) at a school, with an energy star rating that quite impressed me. Maybe one of those for the kitchen. Time to do some research.
The most efficient chest freezers on the Aussie market, according to the official figures, are Denmark-made Vestfrost units - the same brand modified to be a fridge in the earlier link. They have one model which is about the size Michelle would like, 250L, that's rated at a quite frugal 237kWh/year. Would have been a candidate if they weren't so physically large and surprisingly expensive. And imported from the other side of the planet.
Mid-sized efficient freezer options beyond that are surprisingly limited. We quickly narrowed it down to two: a 160L Fisher & Paykel chest rated at 307kWh/year, or a 180L Westinghouse upright freezer rated at 297kWh/year. Westinghouse looks better for us other than being imported from China. So what about the fridge?
Given our simple criteria, there was no contest. Absolutely hands-down, the winner is a brand-new model from Electrolux. A 400L upright single-door fridge that uses just 250kWh/year and it's made here in Australia. This product has the highest energy efficiency score of all 3000 refrigeration units in the database, bar none (it'd score 8 stars, but the ratings only go to six). Price is middle-of-the-range: more than the Asian products and less than the European.
So that was the plan. The Electrolux fridge and the Westinghouse freezer. Combined rated total of 547kWh/year, which is just a smidge under 1.5kWh/day.
Er, hang on. I'm going to spend a couple thousand dollars on the most energy-efficient appliances I can find and still only cut my power consumption by 25%? Admittedly I'd have room for a bit more ice cream... but... only 25%? There's gotta be a better option.
Turns out there is, if I can live with just a single six-pack in the fridge at any one time. Another member of the new Electrolux range is a fairly conventional-looking bottom-mount fridge/freezer. 359L fridge space, 156 in the freezer (more than our old one), and a rated energy use of 428kWh/year. That's good enough for a five-star badge, and it's made right here down under.
So I saved myself a few hundred bucks and improved my energy reduction from 25% to over 40% (based on rated consumption of the new fridge vs actual consumption of the one I had). The fridge was delivered today. Now all I have to do is convince Michelle that going from 120L to 156L really is a significant improvement in freezer capacity and we didn't really need a separate freezer anyway.
Yeah. Wish me luck.
Saturday 15 November 2008
Welcome to my backyard
Some pics for a change.
First up, my mostly-recycled chook pen... with a little addition on the near side which I'll get back to in a minute. The far end is the existing fence. Rear-left is a piece of lattice which some previous owner left lying around this place. Rear-right and the lower half of the front and front-left are rigid mesh fence pieces Mr S had in surplus. The gateway on the right used to be parts of Mr S's neighbour's verandah, while the gate frame itself is cut down from a wardrobe door which I hated. Underneath most of it are old hardwood sleepers which were somebody else's idea of garden borders. The only significant new material was the chicken wire to fill in the gaps above the fence panels and in the gate section.
The hutch doesn't look like much in this pic but by damn it was the hardest part of the job, and is also made from recycled materials. I'll post on it another day.
Right down there in front of the home for chooks is the home for my Jericho beans. Six little sprouts now have a chook-proof, well-nourished, sunny spot with lots of opportunity to climb. You can see in the previous pic the passionfruit vine which has its roots in the neighbour's yard. I'm enjoying that for now but will probably cut it back later on to make a bit more room for the beans. More recycled fence panel, a bit of the wood panel from that hated wardrobe door and even some old White Pages went into the construction of this bit. I confess to buying the compost from the hardware megastore today, but at least it's organic.
And finally, some proof that my back yard is actually capable of supporting some kind of useful plant life: our herb garden. Featured are basil, parsley, chives, chillis, rosemary, sage, marjoram, chickory, spring onions and - if you zoom in and look really carefully - a solitary coriander leaf. Yeah, the garden hasn't yet proved it can support coriander. We have some oregano on stand-by to take its place.
First up, my mostly-recycled chook pen... with a little addition on the near side which I'll get back to in a minute. The far end is the existing fence. Rear-left is a piece of lattice which some previous owner left lying around this place. Rear-right and the lower half of the front and front-left are rigid mesh fence pieces Mr S had in surplus. The gateway on the right used to be parts of Mr S's neighbour's verandah, while the gate frame itself is cut down from a wardrobe door which I hated. Underneath most of it are old hardwood sleepers which were somebody else's idea of garden borders. The only significant new material was the chicken wire to fill in the gaps above the fence panels and in the gate section.
The hutch doesn't look like much in this pic but by damn it was the hardest part of the job, and is also made from recycled materials. I'll post on it another day.
Right down there in front of the home for chooks is the home for my Jericho beans. Six little sprouts now have a chook-proof, well-nourished, sunny spot with lots of opportunity to climb. You can see in the previous pic the passionfruit vine which has its roots in the neighbour's yard. I'm enjoying that for now but will probably cut it back later on to make a bit more room for the beans. More recycled fence panel, a bit of the wood panel from that hated wardrobe door and even some old White Pages went into the construction of this bit. I confess to buying the compost from the hardware megastore today, but at least it's organic.
And finally, some proof that my back yard is actually capable of supporting some kind of useful plant life: our herb garden. Featured are basil, parsley, chives, chillis, rosemary, sage, marjoram, chickory, spring onions and - if you zoom in and look really carefully - a solitary coriander leaf. Yeah, the garden hasn't yet proved it can support coriander. We have some oregano on stand-by to take its place.
Wednesday 5 November 2008
Living History
No, this is not a post about American politics, as historic as this day might be. It's about Aussie back yards.
When I was as young as my son is now - four years old - I lived in a tiny little outback town called Jericho, west of Rockhampton. We were only there for two and a half years but that experience of country life had a big influence on me.
I have some very clear memories of that time, like getting my first bike and the first day I rode it without training wheels. I recall going for a day out in the bush, catching yabbies (crayfish) from the creek and cooking them up for lunch. I remember visiting a property where two huge bulldozers were dragging an enormous chain between them, making one hell of a mess as they tore down the eucalypt forest, clearing it to become grazing land.
Just down the street from us lived another family whose children were too old for me to play with, but Mrs Bonham and my mother became good friends and I spent quite a bit of time playing around the Bonham house and yard. The yard had one particularly distinguishing feature: a thriving green bean vine growing on a free-standing trellis. This so impressed my younger brother and I that we came to gigglingly refer to Mum's friend as "Mrs Bean-Bonham". (Gosh four-year-olds think they're funny.)
We were free to pick and eat the beans as we wished. Sometimes we'd be given big bags of them to take home. Formed in my earliest years, that simple memory epitomises the notion of a bountiful garden. In the past 18 months of mucking about in my own back yard I haven't really come close to recreating that ideal.
But just recently, something special has happened.
The friendship my mother formed has been a lasting one, and from time to time she and Mrs Bonham will exchange a phone call or find an opportunity to meet if travel plans are favourable. In one of their recent conversations, Mum happened to mention that I've been playing about with veges and the like. And this past weekend, Mum handed me a padded envelope which was postmarked in Jericho.
Mrs Bonham's beans have been growing in her garden for nearly 30 years since I used to pick them as a boy. Inside the envelope was a paper-thin, dried out husk of a bean, its green flesh now turned creamy pale, itself acting as a natural envelope for the seeds contained within. Six seeds: richly dark, almost black, except for a bright white protruding ridge running about half way around the centre line.
Joshua (4), Caitlin (7) and the neighbour's boy (7) helped me to plant them. Each pressed two seeds into the moist potting mix and I put the covered tray outside where it will catch the morning sun. Three days later, a living piece of my own childhood is forming roots and shoots which - if I don't manage to kill 'em - will bring that remembered bounty back into reality for me and my kids to enjoy.
Yes, I'm getting all sentimental about bloody beans. I've talked for ages about growing some beans in the back yard. But it's just so special to me that these aren't something which came in a packet from a shop. These beans are living connections for me, to community, to my own history, and to the natural providence of the Earth independent from modern industrial society.
Mrs Bean-Bonham, thank you so much for your gift. Wish me luck as I try to grow these seeds and get the vines scaling up the side of the chicken coup. I'll keep you posted.
When I was as young as my son is now - four years old - I lived in a tiny little outback town called Jericho, west of Rockhampton. We were only there for two and a half years but that experience of country life had a big influence on me.
I have some very clear memories of that time, like getting my first bike and the first day I rode it without training wheels. I recall going for a day out in the bush, catching yabbies (crayfish) from the creek and cooking them up for lunch. I remember visiting a property where two huge bulldozers were dragging an enormous chain between them, making one hell of a mess as they tore down the eucalypt forest, clearing it to become grazing land.
Just down the street from us lived another family whose children were too old for me to play with, but Mrs Bonham and my mother became good friends and I spent quite a bit of time playing around the Bonham house and yard. The yard had one particularly distinguishing feature: a thriving green bean vine growing on a free-standing trellis. This so impressed my younger brother and I that we came to gigglingly refer to Mum's friend as "Mrs Bean-Bonham". (Gosh four-year-olds think they're funny.)
We were free to pick and eat the beans as we wished. Sometimes we'd be given big bags of them to take home. Formed in my earliest years, that simple memory epitomises the notion of a bountiful garden. In the past 18 months of mucking about in my own back yard I haven't really come close to recreating that ideal.
But just recently, something special has happened.
The friendship my mother formed has been a lasting one, and from time to time she and Mrs Bonham will exchange a phone call or find an opportunity to meet if travel plans are favourable. In one of their recent conversations, Mum happened to mention that I've been playing about with veges and the like. And this past weekend, Mum handed me a padded envelope which was postmarked in Jericho.
Mrs Bonham's beans have been growing in her garden for nearly 30 years since I used to pick them as a boy. Inside the envelope was a paper-thin, dried out husk of a bean, its green flesh now turned creamy pale, itself acting as a natural envelope for the seeds contained within. Six seeds: richly dark, almost black, except for a bright white protruding ridge running about half way around the centre line.
Joshua (4), Caitlin (7) and the neighbour's boy (7) helped me to plant them. Each pressed two seeds into the moist potting mix and I put the covered tray outside where it will catch the morning sun. Three days later, a living piece of my own childhood is forming roots and shoots which - if I don't manage to kill 'em - will bring that remembered bounty back into reality for me and my kids to enjoy.
Yes, I'm getting all sentimental about bloody beans. I've talked for ages about growing some beans in the back yard. But it's just so special to me that these aren't something which came in a packet from a shop. These beans are living connections for me, to community, to my own history, and to the natural providence of the Earth independent from modern industrial society.
Mrs Bean-Bonham, thank you so much for your gift. Wish me luck as I try to grow these seeds and get the vines scaling up the side of the chicken coup. I'll keep you posted.
Monday 27 October 2008
Alexander F Mayer
This is not a topic I ever thought I'd be posting about on this blog. To be frank, it's a bit of a stretch to call it relevant, though I'll do my best. Mostly I'm choosing to post this because it's freaking awesome and also because if it turns out to be correct I'd like to go on the public record as having been among the first to acknowledge it.
Alexander F Mayer is what most people would call a serious geek. Way geekier even than myself. I'm not entirely sure of his background and qualifications but he's not a recognised authority amongst his peers in his field of study. Most of them would probably call him a crackpot, or worse.
What makes him postworthy is his rather persuasive and potentially revolutionary theory about the nature of the universe - and I mean the whole universe, from the smallest particle through to the largest supergalactic cluster and the complete extent of time. The theory is published as a digitally signed PDF at www.sensibleuniverse.org, but most people I know wouldn't enjoy reading something that, um, geeky. (If you do - I would really love to hear from you!)
The fundamental idea in Mayer's cosmology is that the conventional understanding of time is as misguided as the ancient belief that the Earth was flat. We are accustomed to thinking that the universe as a whole experiences time just as we do, and that we can represent a history of the entire universe using a single timeline. This naturally leads people to ponder how the universe started and how it might eventually come to an end. If it started in a "Big Bang", then what came before that? And if it started small and is growing larger, what lies beyond the edge of it?
Without going into too much detail, I will say merely that Mayer's universe has no beginning, no end, and no edges. Just as you can travel forever in one direction around the surface of the Earth (a full circle brings you back to your original position) you can imagine a straight path through space in any direction leading you eventually back to the exact point you started from. And just as for every point on the Earth there is a place at the precisely opposite side of the globe, for every point in space there is a precisely opposite place in the universe through which you would pass if you could follow that straight line in any direction for a very, very long time.
Now to make this relevant to my blog.
Black holes, says Mayer, are actually the "in" end of a tunnel through spacetime (ie a wormhole) which leads to the opposite side of the universe. And at that end one finds a "white hole" spewing forth raw energy and fundamental particles. Dead star goes in, elemental ingredients come out. That means 100% recycling of material and energy, occurring everywhere in the universe, for all eternity. Can't get much more sustainable than that.
Beyond the physics, Mayer's publication concludes with some fascinating comments on the interaction between science, philosophy, society and even religion. If the universe really is as he describes, then human psychology might have some adjusting to do. Instead of a one-way trip from bang to bust, the universe continually recreates itself. Theoretically, our descendants could inhabit Mayer's universe forever. If only we can avoid destroying this one little part of it in the meantime.
Alexander F Mayer is what most people would call a serious geek. Way geekier even than myself. I'm not entirely sure of his background and qualifications but he's not a recognised authority amongst his peers in his field of study. Most of them would probably call him a crackpot, or worse.
What makes him postworthy is his rather persuasive and potentially revolutionary theory about the nature of the universe - and I mean the whole universe, from the smallest particle through to the largest supergalactic cluster and the complete extent of time. The theory is published as a digitally signed PDF at www.sensibleuniverse.org, but most people I know wouldn't enjoy reading something that, um, geeky. (If you do - I would really love to hear from you!)
The fundamental idea in Mayer's cosmology is that the conventional understanding of time is as misguided as the ancient belief that the Earth was flat. We are accustomed to thinking that the universe as a whole experiences time just as we do, and that we can represent a history of the entire universe using a single timeline. This naturally leads people to ponder how the universe started and how it might eventually come to an end. If it started in a "Big Bang", then what came before that? And if it started small and is growing larger, what lies beyond the edge of it?
Without going into too much detail, I will say merely that Mayer's universe has no beginning, no end, and no edges. Just as you can travel forever in one direction around the surface of the Earth (a full circle brings you back to your original position) you can imagine a straight path through space in any direction leading you eventually back to the exact point you started from. And just as for every point on the Earth there is a place at the precisely opposite side of the globe, for every point in space there is a precisely opposite place in the universe through which you would pass if you could follow that straight line in any direction for a very, very long time.
Now to make this relevant to my blog.
Black holes, says Mayer, are actually the "in" end of a tunnel through spacetime (ie a wormhole) which leads to the opposite side of the universe. And at that end one finds a "white hole" spewing forth raw energy and fundamental particles. Dead star goes in, elemental ingredients come out. That means 100% recycling of material and energy, occurring everywhere in the universe, for all eternity. Can't get much more sustainable than that.
Beyond the physics, Mayer's publication concludes with some fascinating comments on the interaction between science, philosophy, society and even religion. If the universe really is as he describes, then human psychology might have some adjusting to do. Instead of a one-way trip from bang to bust, the universe continually recreates itself. Theoretically, our descendants could inhabit Mayer's universe forever. If only we can avoid destroying this one little part of it in the meantime.
Saturday 18 October 2008
Stats Update
In the past 45 days...
Our solar panels have produced 187kWh of electricity (4.16/day).
87kWh of that has been exported to the grid (1.93/day), while 100kWh has been used immediately in our home (2.22/day).
We have consumed an additional 279kWh from the grid (6.2/day).
Total consumption is therefore 279+100=379kWh (8.42/day).
We have also used the electric booster for our hot water occasionally: 10.9kWh total (0.24/day).
Scaled up to 3 months, our bill (should AGL ever get around to sending us one) would look like this...
Tariff 11: 558kWh @ 16.29c = $90.90
Tariff 33: 22kWh @ 9.78c = $2.16
Solar export tariff: 174kWh @ 44c = $76.56 credit
Total: $16.50
Well, except that there's a monthly service fee of $6.26 for tariff 11 and the minimum monthly cost on tariff 33 is $4.36. So that brings it up to $37.48. I'd actually save $9.50 per bill if I switched my hot water booster to tariff 11... but there's a $50 charge for the swapover, which means a 15 month payback time.
Bottom line: at this point in time our 1kW array is producing just under half of our home's total energy needs, though only about half of that is produced when we actually need it. Thanks to the government's feed-in tariff, that misalignment of supply and demand has a very positive impact on our electricity bills. The energy we export is valued at 80% of the energy we import. The additional amount we produce and consume locally is effectively worth another $33 or so that doesn't appear on the bill.
Our solar panels have produced 187kWh of electricity (4.16/day).
87kWh of that has been exported to the grid (1.93/day), while 100kWh has been used immediately in our home (2.22/day).
We have consumed an additional 279kWh from the grid (6.2/day).
Total consumption is therefore 279+100=379kWh (8.42/day).
We have also used the electric booster for our hot water occasionally: 10.9kWh total (0.24/day).
Scaled up to 3 months, our bill (should AGL ever get around to sending us one) would look like this...
Tariff 11: 558kWh @ 16.29c = $90.90
Tariff 33: 22kWh @ 9.78c = $2.16
Solar export tariff: 174kWh @ 44c = $76.56 credit
Total: $16.50
Well, except that there's a monthly service fee of $6.26 for tariff 11 and the minimum monthly cost on tariff 33 is $4.36. So that brings it up to $37.48. I'd actually save $9.50 per bill if I switched my hot water booster to tariff 11... but there's a $50 charge for the swapover, which means a 15 month payback time.
Bottom line: at this point in time our 1kW array is producing just under half of our home's total energy needs, though only about half of that is produced when we actually need it. Thanks to the government's feed-in tariff, that misalignment of supply and demand has a very positive impact on our electricity bills. The energy we export is valued at 80% of the energy we import. The additional amount we produce and consume locally is effectively worth another $33 or so that doesn't appear on the bill.
Wednesday 30 July 2008
The meter goes backwards
It's been a long time coming but we finally have a 1KW photovoltaic array on our roof. Too much detail to post via iPhone keyboard... but I watched our meter turning the other way this arvo. Way cool.
Tuesday 17 June 2008
Heeeere, chook chook chooky!
We want chickens.
Chickens need somewhere safe to live and lay their eggs.
I avoid buying new materials.
I pretty much refuse to use concrete.
I use hand-powered tools whenever it's an option.
There was some junk lying around the yard and the shed.
My mate (Mr S) had some even cooler junk in his yard.
We're not stuck-up about the appearance of our garden.
It's a work in progress.
I'll post some pics once I complete the walls.
Chickens need somewhere safe to live and lay their eggs.
I avoid buying new materials.
I pretty much refuse to use concrete.
I use hand-powered tools whenever it's an option.
There was some junk lying around the yard and the shed.
My mate (Mr S) had some even cooler junk in his yard.
We're not stuck-up about the appearance of our garden.
It's a work in progress.
I'll post some pics once I complete the walls.
Meter matters
Two real-life examples of why meters are your friend and reading them is a good idea.
1. "Where did our water go?"
We've had a lot of rain this month. Following a two month stretch during which a total of 26mm fell at our place, we had over 220mm in just five days. That's enough to fill our tanks four times over. With no room for more water, I decided to let any further showers flush out the internal dirty water diverters and opened up the valves. Then promptly forgot about it.
It rained twice more in the following three days: falls of just a few mm but enough that I expected to see the new inflows make up for the water we'd pumped out for the laundry and toilet. But for some reason the gauge didn't go up. In fact it was heading downwards at a surprising rate - around 10cm (800L) in two days. I figured we must have been catching up on a lot of washing.
Two days later we were down another 800L. Something finally triggered my memory - the diverter valves were open! I suddenly recalled that the internal hose which allows the diverter to drain to the outside is not watertight, which means that water from the main chamber can slowly leak out when the drain valve is opened. We must have wasted well over a thousand litres this way.
If I hadn't put a gauge on the tanks and made a habit of checking it, we'd have lost half our supply (the valves are about halfway up the tank wall) within a few more days.
2. "The bill is for how much?!"
A week ago as I sat here working in my home office I noticed somebody briefly inspecting our electrical meter box. "Ah," I thought, "our quarterly electricity bill will be turning up soon." Well turn up it certainly did!
With all that rainy weather I mentioned just before, we had to use the electric booster on our hot water system for a couple of days. Imagine my surprise when the total bill came in at well over twice what I'd been expecting, with an off peak consumption for the quarter of one thousand, five hundred and twenty six kilowatt-hours! The charge for that was almost as much as I'd budgeted for the whole bill.
I hadn't read the meters since a few days before it rained, so I rushed out to check them. After sitting on 90615.3 for about eight months, the off-peak meter today reads... 90638.1. A grand total of 22.8kWh difference.
That's actually more than I'd been hoping to see given how little we used the booster, but it's rather insignificant compared to the matter of the invoice. The meter for the constant supply had also been recorded incorrectly - even today, a week after the reading, I'm still 157kWh short of what they're claiming. It'll take us another 20 days to reach that point.
The lady on the phone conceded that it was a bit odd to have such a spike, although for some reason this bill is recorded as being an "estimated" value. She spent a long time conferring with a supervisor before agreeing that the meter should be re-read. The soonest they could get somebody here would be the 20th (I told them not to rush on my account - I'm in no hurry to get a bill). And she made it sound like she was doing me a favour not charging me the customary $24 fee for a repeat reading (like hell I'm going to pay for them to fix their screw-up).
Ah well, I probably won't be paying too many more bills to that company anyway. I was already looking into switching retailers to get a better rate for the energy my PV panels will produce - 20c instead of 14c per kWh. And once that gear's installed you can bet I'll be watching the new meter closely indeed.
1. "Where did our water go?"
We've had a lot of rain this month. Following a two month stretch during which a total of 26mm fell at our place, we had over 220mm in just five days. That's enough to fill our tanks four times over. With no room for more water, I decided to let any further showers flush out the internal dirty water diverters and opened up the valves. Then promptly forgot about it.
It rained twice more in the following three days: falls of just a few mm but enough that I expected to see the new inflows make up for the water we'd pumped out for the laundry and toilet. But for some reason the gauge didn't go up. In fact it was heading downwards at a surprising rate - around 10cm (800L) in two days. I figured we must have been catching up on a lot of washing.
Two days later we were down another 800L. Something finally triggered my memory - the diverter valves were open! I suddenly recalled that the internal hose which allows the diverter to drain to the outside is not watertight, which means that water from the main chamber can slowly leak out when the drain valve is opened. We must have wasted well over a thousand litres this way.
If I hadn't put a gauge on the tanks and made a habit of checking it, we'd have lost half our supply (the valves are about halfway up the tank wall) within a few more days.
2. "The bill is for how much?!"
A week ago as I sat here working in my home office I noticed somebody briefly inspecting our electrical meter box. "Ah," I thought, "our quarterly electricity bill will be turning up soon." Well turn up it certainly did!
With all that rainy weather I mentioned just before, we had to use the electric booster on our hot water system for a couple of days. Imagine my surprise when the total bill came in at well over twice what I'd been expecting, with an off peak consumption for the quarter of one thousand, five hundred and twenty six kilowatt-hours! The charge for that was almost as much as I'd budgeted for the whole bill.
I hadn't read the meters since a few days before it rained, so I rushed out to check them. After sitting on 90615.3 for about eight months, the off-peak meter today reads... 90638.1. A grand total of 22.8kWh difference.
That's actually more than I'd been hoping to see given how little we used the booster, but it's rather insignificant compared to the matter of the invoice. The meter for the constant supply had also been recorded incorrectly - even today, a week after the reading, I'm still 157kWh short of what they're claiming. It'll take us another 20 days to reach that point.
The lady on the phone conceded that it was a bit odd to have such a spike, although for some reason this bill is recorded as being an "estimated" value. She spent a long time conferring with a supervisor before agreeing that the meter should be re-read. The soonest they could get somebody here would be the 20th (I told them not to rush on my account - I'm in no hurry to get a bill). And she made it sound like she was doing me a favour not charging me the customary $24 fee for a repeat reading (like hell I'm going to pay for them to fix their screw-up).
Ah well, I probably won't be paying too many more bills to that company anyway. I was already looking into switching retailers to get a better rate for the energy my PV panels will produce - 20c instead of 14c per kWh. And once that gear's installed you can bet I'll be watching the new meter closely indeed.
Saturday 31 May 2008
More good news about slime
I am frequently critical of "biofuels" technology because of issues like poor (or negative) payback in energy terms and the competition for food production and so on. Once or twice I have mentioned algae as a possible alternative "crop" which may be able to capture solar energy in a chemical form that's suitable for production of liquid fuels. Well, the prospects for a bright slimy green future just got better.
A mob in the US has announced that they have developed a process for producing gasoline from algae, using wastewater to support the algal growth. The key breakthrough is that the fuel they're making is chemically identical to the stuff that we put in our cars today rather than "biodiesel": this makes it a potential direct substitute fuel requiring no change to existing fuel processing and handling systems and no change to our engines.
Of course I'm still going to advocate radical efficiency improvements a la Amory Lovins, but if this technology turns out to be viable and scalable without significant drawbacks then it's going to make a huge difference.
Read more via this link.
About time I could tag a post with "hopes".
A mob in the US has announced that they have developed a process for producing gasoline from algae, using wastewater to support the algal growth. The key breakthrough is that the fuel they're making is chemically identical to the stuff that we put in our cars today rather than "biodiesel": this makes it a potential direct substitute fuel requiring no change to existing fuel processing and handling systems and no change to our engines.
Of course I'm still going to advocate radical efficiency improvements a la Amory Lovins, but if this technology turns out to be viable and scalable without significant drawbacks then it's going to make a huge difference.
Read more via this link.
About time I could tag a post with "hopes".
Thursday 29 May 2008
More water, but it's all cold
Good news: it's raining again and the tanks are now over 50% full with more falls forecast for this weekend.
Bad news: combined with the lower temperatures and reduced sun intensity of winter, the persistent cloud has forced us to switch on the electric backup for our solar hot water system. It's been seven months since the electricity company saw that meter move.
Ah well.
Bad news: combined with the lower temperatures and reduced sun intensity of winter, the persistent cloud has forced us to switch on the electric backup for our solar hot water system. It's been seven months since the electricity company saw that meter move.
Ah well.
Sunday 25 May 2008
Gardening update
It's about a year now since I first decided to try and grow some food in the backyard. Last autumn I was posting about the my first attempt, the tomatoes in a pot. Time for a review and a look at what's ahead.
So what have I got to show for my past year's efforts? Dead tomatoes. Dead capsicums. Dead cucumbers. Dead strawberries. Dead carrots. We did get to eat a few handfuls of tiny cherry tomatoes, several strawberries and a couple of capsicums, but on the whole... I'm really glad the shops still have plenty of food in them.
There is good news with the bad though, because I've learned things through these failures. Most of what we planted was grown in pots with soil from the garden bed I excavated to make way for one of the tanks. My conclusion is that that soil sucks. It really didn't hold water well and appeared to be lacking a great deal in nutrients.
The plants which grew the best were the capsicums, and they were transferred into the ground as seedlings with a layer of home-made compost and mulch on the top. They grew vigourously and fruited like mad - only to have the fruit flies destroy almost every last one. That garden bed is now seemingly lifeless, with the nutrients depleted, the sun keeping it hot and dry and the mulch (woodchips, really) still keeping even the weed seeds at bay. I have an experiment forming in the back of my mind to do a soil improvement project over winter using comfrey or something and then have another go at the capsicums since they seemed to like that spot.
Taking heart from the way the capsicums responded to the compost and mulch treatment, over the past few months we've converted a weedy, wet corner of the yard (just in between the fence and the patio) into a herb garden. It was full of clover and some other leafy weeds and a bit clay-bound so I took a garden fork to it and churned it up. Not much "soil structure" there to be destroying, don't worry. I then mixed in a generous amount of well-aged compost, and promptly ignored it for weeks. The weeds grew back with renewed vigour of course. And then we got serious.
Lots of weeds got ripped out and fed into the new compost bin. A thick layer of newspaper covered the ground with holes left where the chives, sage and marjoram (gifts from a friend) were planted. On top of that went a layer of recycled pine bark mulch that a neighbour was throwing away. Since then we've expanded the crop with basil, parsley, rosemary, challots and a little chilli bush. And they're thriving!
The chillis quickly became infested with what I think are aphids... complete with the "farmer" ants tending them. The plant is still flowering, fruiting and looking generally healthy but I'm sure it would be better off without them, so this arvo I took action. I found a recipe on the net for "white oil" - a mixture of vegetable oil (I used olive), water and dishwashing detergent. This has been sprayed liberally on the plant and as far as I can see the aphids are in fact now dead. Fingers crossed that the plant will survive.
My other proud success is the quality of the compost that I've made. OK, it's not that hard, but it's still deeply encouraging to see the cycle of life playing itself out with such calm assurance, relentlessly renewing. It makes me realise that my main responsibility is to learn how life works and just facilitate it. The new bin accelerates the process and takes some of the manual effort out of it. And in the spirit of facilitating, earlier I scooped out a few handfuls from the bottom (mostly material which I had transferred from my previous heap to get this bin started) and introduced some of my worms.
Yes - my worm farm is still alive! They don't eat anywhere near as much as I'd hoped but they're still going. Maybe the compost bin will be a more appetising home for these worms and certainly they can't do anything but contribute to the process... even if it's just by becoming raw material.
The compost that I removed, I sieved to get rid of the woody bits and then took a close look. It's dark brown, but distinctly not black. It's light, spongy, and if you squish it it retains its shape. But it's also "crumbly", in that you can break it apart into light, spongy pieces again by rolling it between your fingers. And it has almost no odour at all. From the descriptions I've read... this is exactly as it ought to be.
I'm going to grow food in my backyard. It's just a matter of time.
So what have I got to show for my past year's efforts? Dead tomatoes. Dead capsicums. Dead cucumbers. Dead strawberries. Dead carrots. We did get to eat a few handfuls of tiny cherry tomatoes, several strawberries and a couple of capsicums, but on the whole... I'm really glad the shops still have plenty of food in them.
There is good news with the bad though, because I've learned things through these failures. Most of what we planted was grown in pots with soil from the garden bed I excavated to make way for one of the tanks. My conclusion is that that soil sucks. It really didn't hold water well and appeared to be lacking a great deal in nutrients.
The plants which grew the best were the capsicums, and they were transferred into the ground as seedlings with a layer of home-made compost and mulch on the top. They grew vigourously and fruited like mad - only to have the fruit flies destroy almost every last one. That garden bed is now seemingly lifeless, with the nutrients depleted, the sun keeping it hot and dry and the mulch (woodchips, really) still keeping even the weed seeds at bay. I have an experiment forming in the back of my mind to do a soil improvement project over winter using comfrey or something and then have another go at the capsicums since they seemed to like that spot.
Taking heart from the way the capsicums responded to the compost and mulch treatment, over the past few months we've converted a weedy, wet corner of the yard (just in between the fence and the patio) into a herb garden. It was full of clover and some other leafy weeds and a bit clay-bound so I took a garden fork to it and churned it up. Not much "soil structure" there to be destroying, don't worry. I then mixed in a generous amount of well-aged compost, and promptly ignored it for weeks. The weeds grew back with renewed vigour of course. And then we got serious.
Lots of weeds got ripped out and fed into the new compost bin. A thick layer of newspaper covered the ground with holes left where the chives, sage and marjoram (gifts from a friend) were planted. On top of that went a layer of recycled pine bark mulch that a neighbour was throwing away. Since then we've expanded the crop with basil, parsley, rosemary, challots and a little chilli bush. And they're thriving!
The chillis quickly became infested with what I think are aphids... complete with the "farmer" ants tending them. The plant is still flowering, fruiting and looking generally healthy but I'm sure it would be better off without them, so this arvo I took action. I found a recipe on the net for "white oil" - a mixture of vegetable oil (I used olive), water and dishwashing detergent. This has been sprayed liberally on the plant and as far as I can see the aphids are in fact now dead. Fingers crossed that the plant will survive.
My other proud success is the quality of the compost that I've made. OK, it's not that hard, but it's still deeply encouraging to see the cycle of life playing itself out with such calm assurance, relentlessly renewing. It makes me realise that my main responsibility is to learn how life works and just facilitate it. The new bin accelerates the process and takes some of the manual effort out of it. And in the spirit of facilitating, earlier I scooped out a few handfuls from the bottom (mostly material which I had transferred from my previous heap to get this bin started) and introduced some of my worms.
Yes - my worm farm is still alive! They don't eat anywhere near as much as I'd hoped but they're still going. Maybe the compost bin will be a more appetising home for these worms and certainly they can't do anything but contribute to the process... even if it's just by becoming raw material.
The compost that I removed, I sieved to get rid of the woody bits and then took a close look. It's dark brown, but distinctly not black. It's light, spongy, and if you squish it it retains its shape. But it's also "crumbly", in that you can break it apart into light, spongy pieces again by rolling it between your fingers. And it has almost no odour at all. From the descriptions I've read... this is exactly as it ought to be.
I'm going to grow food in my backyard. It's just a matter of time.
Renewing my energy
Just a quick one. I haven't mentioned yet that I attended a forum this past week at City Hall, where I heard talks by Andrew McNamara, Judy Wicks (www.whitedog.com), Gilbert Rochecouste (www.villagewell.org) and Robert Pekin (www.foodconnect.com.au), and saw a new peak oil documentary produced locally (aquilaproductions.com.au).
It was wonderfully inspiring, if a little sobering... not so much a pep rally as a recruitment drive in a war effort. Hmm.
So I have a renewed sense of urgency which has already prompted me to consider a carectomy, cut way back on my meat and dairy consumption (even on Ice Break) and have another stab at the backyard gardening. I also wrote letters (emails) to various people at the state, city and local community levels expressing my concern regarding the issues and my desire to be part of the solutions.
Would have been at Northey St Community Garden this morning if it weren't for the badly interrupted sleep #2 and #3 gave us last night. Instead I'm going to look at designs for chicken tractors.
Some time soon I'm going to review and update my action plan.
It was wonderfully inspiring, if a little sobering... not so much a pep rally as a recruitment drive in a war effort. Hmm.
So I have a renewed sense of urgency which has already prompted me to consider a carectomy, cut way back on my meat and dairy consumption (even on Ice Break) and have another stab at the backyard gardening. I also wrote letters (emails) to various people at the state, city and local community levels expressing my concern regarding the issues and my desire to be part of the solutions.
Would have been at Northey St Community Garden this morning if it weren't for the badly interrupted sleep #2 and #3 gave us last night. Instead I'm going to look at designs for chicken tractors.
Some time soon I'm going to review and update my action plan.
Saturday 24 May 2008
Stats Update
It's 19 days since my last stats update, when the tank levels had fallen so low I switched the washing machine and toilet back to using mains water. I had calculated at the time that we had been using about 250L/day of tank water plus almost 200L from the mains. It's no surprise then that our recent mains consumption has been...
409L/day.
More than we were using over summer, but back then we had #3 in disposable nappies and now we're washing cloth ones almost daily. Less than I estimated we were using in the previous period... we are probably a bit more diligent with our conservation knowing we're back on mains supply.
After a month of zero rainfall, last weekend delivered a lovely little squall and dumped 14mm on us in under an hour. Approx 2.2kL added to the tanks, around 30cm above empty now. With the prospect for winter rains looking grim I switched the toilet back to tank water but left the washing machine on mains.
Power consumption for the past few weeks fell to the second-lowest reading this year: 7.3kWh per day (304W continuous).
409L/day.
More than we were using over summer, but back then we had #3 in disposable nappies and now we're washing cloth ones almost daily. Less than I estimated we were using in the previous period... we are probably a bit more diligent with our conservation knowing we're back on mains supply.
After a month of zero rainfall, last weekend delivered a lovely little squall and dumped 14mm on us in under an hour. Approx 2.2kL added to the tanks, around 30cm above empty now. With the prospect for winter rains looking grim I switched the toilet back to tank water but left the washing machine on mains.
Power consumption for the past few weeks fell to the second-lowest reading this year: 7.3kWh per day (304W continuous).
Wednesday 21 May 2008
A proposal for a means-tested PVRP
Following up on the previous post, this one explores some options for the design of a solar photovoltaic rebate program. Hopefully a better one than what we have in the real world today.
First let's look at the goals of the program. Overall, the intention is to invest a fixed amount of money over a fixed time period into the PV industry. There are a number of anticipated benefits for society as a whole:
- Develop the skills and infrastructure required for a sustainable PV industry
- Encourage R&D for technology improvement
- Put downward pressure on costs
- Improve competitiveness and effectiveness of PV in the long term
I would also like to throw my own goal in there (to nobody's surprise), encouraging overall reduced energy consumption in participating homes.
Now, the only reason I'm writing this is because I'm critical of the previous attempts on both sides of politics to implement this scheme. Specifically:
- A fixed rebate value skews investment heavily towards the smallest eligible system
- A fixed rebate value without a means test is socially inequitable
- An all-or-nothing means test is more equitable on average but introduces ridiculous boundary cases
- With or without the means test, the scheme ignores the number of residents in the household
The number of residents in the household is important for several reasons. In a scheme where a means test is imposed, surely the case of a single person living alone earning a hundred grand should be considered differently to a working couple with children making do on the same amount. Also, one of the factors involved in choosing whether to purchase a PV system is the amount of time it'll take to recoup the costs, and that gets us back to the topic of feed-in-tariffs. Under the import/export models being adopted by the states it's clearly easier for the single person to generate excess energy than it is for the family.
So I propose that a good rebate scheme would be variable. Different amounts should be paid in different circumstances, according to some reasonable criteria. The scheme should offer greater assistance to those with the greater need, but in all cases part of the cost must be borne by the recipients. Good in principle... but tricky to deliver. Here we go.
First I would suggest that the number of household residents be taken into account when evaluating "means". The simplest way is to divide the household income by the number of residents to work out an income-per-person figure. The single guy mentioned earlier scores $100K, the family of four comes in at $25K each. We'll come back to that in a bit.
My next proposal is that the maximum value of the rebate per household should also be relative to the number of persons. That is, a household with more people should be eligible for more rebate. However there's a risk here that providing funds too freely will encourage profit-taking in the installation industry, and this needs to be addressed.
One way to do this is to also tie the maximum applicable rebate to the generating capacity of the system being installed. We start by nominating a minimum "per-person generating capacity" figure - I'll choose 500W for convenience. Then in order to receive the full rebate for each of the four members of the family household, a system with at least 2000W rated output must be installed. If the family decided to install only a 1000W system, they would be eligible for only half as much rebate. (I hope that makes sense - I'll do some examples at the end.)
Now we need to work out the maximum rebate each person would be eligible to receive. The simplest way to do this is on a linear scale: we need to define the maximum value of the rebate and the upper limit of per-person income at which point the rebate reduces to zero. In keeping with the existing scheme, let's set the maximum rebate to $8,000 and the cut-off at $100K. That means somebody with a "means" of $50K would be eligible for $4,000; somebody worth $75K could get $2,000; and somebody enjoying a hundred grand to themself would get nothing.
Just one more thing. We really don't want to get into the situation where the value of the rebates produces upward pressure on the costs of the PV systems. So let's set an overall threshold which ensures that the household has an incentive to shop around: the total rebate payable shall not exceed 80% of the installed cost of the system.
Simple, huh? No really, it's not that complicated. Here are a couple of examples.
1. Bruce and Sharon live in a house they've bought together. Bruce is a public servant earning $50K while Shazza's cornered the market for organic lima beans and is raking in $100K. Two people in the household, with an average "means" of $75K. The household is therefore eligible for a maximum rebate of $2,000 per person, depending on the size of the array they install. With two people there's really only one option in array size: an entry-level system with a rated output of 1kW makes them eligible for the full $4,000. The best price they can find on such a system is $10,461. Since their maximum rebate is well under 80% of the total price it is paid in full and their net cost is $6,461.
2. Helen, Gary and their four kids somehow manage to get by on the $60K which Gary earns through his small business. With an average "means" of $10K per person, they are each eligible for up to $7,200 in solar rebates - provided sufficient capacity is installed. The maximum rebate would be applicable for a system rated at least 3kW (6 x 500W). Such a system is available for $26,361 - clearly far lower than the hypothetical value of the rebate at $43,200. In this case the 80% rule applies, limiting the rebate to $21,088. Helen and Gary decide they can't afford to spend over $5K even for such a large system, and instead opt for a 1.5kW system that with an 80% rebate leaves them with an outlay of just under $3K.
Some key points to remember. First, I'm just some guy with a few ideas and an internet connection. Don't crucify me if there's something really flawed with my suggestions. Second, there are a number of parameters here which could be adjusted to alter the amount of rebate payable in different circumstances, including the maximum per-person rebate amount, the threshold at which the rebate cuts out completely, the amount of generating capacity required per-person to qualify for that portion of the aggregate rebate and the fractional ceiling limiting the overall rebate as a proportion of the system's cost.
One big weakness I see here is that it's hard to predict how quickly the scheme would burn through its budget allocation. A possible remedy would be to vary the rebate parameters on a periodic basis - probably as part of each year's federal budget.
So there you go. That's enough of that I think.
First let's look at the goals of the program. Overall, the intention is to invest a fixed amount of money over a fixed time period into the PV industry. There are a number of anticipated benefits for society as a whole:
- Develop the skills and infrastructure required for a sustainable PV industry
- Encourage R&D for technology improvement
- Put downward pressure on costs
- Improve competitiveness and effectiveness of PV in the long term
I would also like to throw my own goal in there (to nobody's surprise), encouraging overall reduced energy consumption in participating homes.
Now, the only reason I'm writing this is because I'm critical of the previous attempts on both sides of politics to implement this scheme. Specifically:
- A fixed rebate value skews investment heavily towards the smallest eligible system
- A fixed rebate value without a means test is socially inequitable
- An all-or-nothing means test is more equitable on average but introduces ridiculous boundary cases
- With or without the means test, the scheme ignores the number of residents in the household
The number of residents in the household is important for several reasons. In a scheme where a means test is imposed, surely the case of a single person living alone earning a hundred grand should be considered differently to a working couple with children making do on the same amount. Also, one of the factors involved in choosing whether to purchase a PV system is the amount of time it'll take to recoup the costs, and that gets us back to the topic of feed-in-tariffs. Under the import/export models being adopted by the states it's clearly easier for the single person to generate excess energy than it is for the family.
So I propose that a good rebate scheme would be variable. Different amounts should be paid in different circumstances, according to some reasonable criteria. The scheme should offer greater assistance to those with the greater need, but in all cases part of the cost must be borne by the recipients. Good in principle... but tricky to deliver. Here we go.
First I would suggest that the number of household residents be taken into account when evaluating "means". The simplest way is to divide the household income by the number of residents to work out an income-per-person figure. The single guy mentioned earlier scores $100K, the family of four comes in at $25K each. We'll come back to that in a bit.
My next proposal is that the maximum value of the rebate per household should also be relative to the number of persons. That is, a household with more people should be eligible for more rebate. However there's a risk here that providing funds too freely will encourage profit-taking in the installation industry, and this needs to be addressed.
One way to do this is to also tie the maximum applicable rebate to the generating capacity of the system being installed. We start by nominating a minimum "per-person generating capacity" figure - I'll choose 500W for convenience. Then in order to receive the full rebate for each of the four members of the family household, a system with at least 2000W rated output must be installed. If the family decided to install only a 1000W system, they would be eligible for only half as much rebate. (I hope that makes sense - I'll do some examples at the end.)
Now we need to work out the maximum rebate each person would be eligible to receive. The simplest way to do this is on a linear scale: we need to define the maximum value of the rebate and the upper limit of per-person income at which point the rebate reduces to zero. In keeping with the existing scheme, let's set the maximum rebate to $8,000 and the cut-off at $100K. That means somebody with a "means" of $50K would be eligible for $4,000; somebody worth $75K could get $2,000; and somebody enjoying a hundred grand to themself would get nothing.
Just one more thing. We really don't want to get into the situation where the value of the rebates produces upward pressure on the costs of the PV systems. So let's set an overall threshold which ensures that the household has an incentive to shop around: the total rebate payable shall not exceed 80% of the installed cost of the system.
Simple, huh? No really, it's not that complicated. Here are a couple of examples.
1. Bruce and Sharon live in a house they've bought together. Bruce is a public servant earning $50K while Shazza's cornered the market for organic lima beans and is raking in $100K. Two people in the household, with an average "means" of $75K. The household is therefore eligible for a maximum rebate of $2,000 per person, depending on the size of the array they install. With two people there's really only one option in array size: an entry-level system with a rated output of 1kW makes them eligible for the full $4,000. The best price they can find on such a system is $10,461. Since their maximum rebate is well under 80% of the total price it is paid in full and their net cost is $6,461.
2. Helen, Gary and their four kids somehow manage to get by on the $60K which Gary earns through his small business. With an average "means" of $10K per person, they are each eligible for up to $7,200 in solar rebates - provided sufficient capacity is installed. The maximum rebate would be applicable for a system rated at least 3kW (6 x 500W). Such a system is available for $26,361 - clearly far lower than the hypothetical value of the rebate at $43,200. In this case the 80% rule applies, limiting the rebate to $21,088. Helen and Gary decide they can't afford to spend over $5K even for such a large system, and instead opt for a 1.5kW system that with an 80% rebate leaves them with an outlay of just under $3K.
Some key points to remember. First, I'm just some guy with a few ideas and an internet connection. Don't crucify me if there's something really flawed with my suggestions. Second, there are a number of parameters here which could be adjusted to alter the amount of rebate payable in different circumstances, including the maximum per-person rebate amount, the threshold at which the rebate cuts out completely, the amount of generating capacity required per-person to qualify for that portion of the aggregate rebate and the fractional ceiling limiting the overall rebate as a proportion of the system's cost.
One big weakness I see here is that it's hard to predict how quickly the scheme would burn through its budget allocation. A possible remedy would be to vary the rebate parameters on a periodic basis - probably as part of each year's federal budget.
So there you go. That's enough of that I think.
Monday 19 May 2008
About that PV rebate means test
Hi again.
By now I expect you've all heard that in last week's federal budget, the first under this new management, it was announced that the Photovoltaic Rebate Program (PVRP) would immediately be subjected to means testing. Specifically, the $8,000 rebate would not be available to households whose combined income exceeds $100,000 per annum.
Predictably, there's been an enraged outcry from the renewable energy industry and green groups, and of course the opposition parties have seized the opportunity to attack the government's credibility on climate change policy. ("Hi Kettle, I'm Pot! My, you're a lovely black colour aren't you?")
Like many commentators I have great sympathy for the small business owners and employees who've been enjoying a surge in PV installation activity as a direct consequence of the PVRP and who are now dealing with a sudden drop in orders. Yet I do not necessarily agree that the PVRP should have been left as it was. Let me explain.
In the back of your mind you must always remember this: photovoltaic technology is really neat, but it's a long way from ideal. For starters, today's PV is generally more expensive than other renewables. And it only generates power while the Sun is shining brightly. No matter how many solar panels we install in this country we'll always have need for other energy systems which generate significant power for the other 16 hours per day.
As a rule, I was no fan of the former government. So hopefully it should get your attention when I say that the basic premise behind the PVRP was pretty sound. $150M was allocated over five years to encourage industry development and hence further R&D in PV technology - not to generate as much electricity as possible! Maybe they were forced into it, I don't know, but it was a sensible notion to invest public funds in a promising sector of the renewable energy industry. Unfortunately... they didn't follow through with a sensible rebate scheme for the distribution of those funds.
The PVRP previously offered a flat $4,000. Better than a kick in the teeth, but with PV systems starting at around $12K for an average output of 4kWh per day even that wasn't enough to spur a lot of interest. The "battlers" still couldn't afford it and the more well-off could get better rates of financial return from other forms of "investment". So last year, possibly reading the pre-election mood re climate change, they doubled the rebate to $8,000.
Well didn't that just open the floodgates. They halved the effective cost of an entry-level PV system, bringing it within the reach of middle Australia and making the financial payback time far more acceptable. The take-up rate exploded, "with 35% of all solar installed in eight years of the program occurring in the last six months." (Quote from ATA e-bulletin 19 May 2008).
Poor Mr Swan. Elected to government on the promise of leadership on climate change, faced with the economic necessity of slashing government spending, he had to deal with a PVRP that had gotten out of control and was burning through its multi-year budgetary allocation at an alarming rate. There were only two options: put the brakes on the rate at which money was being paid out (by lowering the amount per payment or limiting its availability) or let it continue to accelerate before slamming into a brick wall a little way down the track when the money runs out. Clearly the brick wall option would be catastrophic for the very PV industry which the program was intended to foster.
So the new management decided to slow the rate of payments by introducing a means test, in line with the general policy of targeting financial assistance to those who need it most. In my personal opinion, that was a reasonable thing to do. The biggest thing to criticise is that it's an all-or-nothing measure tacked on to what was a poorly-designed rebate scheme in the first place.
Just for the fun of it I'm going to do a separate post discussing the actual impact of the means test, how it might relate to the also-announced green loans scheme, and explore an alternate design for a PVRP means test.
To wrap up this one, though, I would ask you to keep looking at the bigger picture and reserve your final judgement on this government's climate change credibility until we see their response to the Garnaut review. The PVRP is something that was inherited and that, politically, had to be carefully managed. Failure to slow the rate of payout would have harmed the PV industry and been attacked by the opposition as financially irresponsible. Axing the scheme (presumably in favour of something better down the track) or reducing the rebate would have sparked a political feeding frenzy. It had to be maintained, but carefully.
The Minister for the Environment put it this way on ABC TV: "We've got programs out there... which will ensure there is enough demand in the Australian community in the long term to get solar panels on roofs... and to make sure that we continue to build a sustainable solar industry into the long term."
Mind you, the other climate change measures announced in the budget weren't terribly inspiring... my guess is it'll be another year, the post-Garnaut budget, before we know whether the promised leadership will be delivered. Let's keep up the pressure.
By now I expect you've all heard that in last week's federal budget, the first under this new management, it was announced that the Photovoltaic Rebate Program (PVRP) would immediately be subjected to means testing. Specifically, the $8,000 rebate would not be available to households whose combined income exceeds $100,000 per annum.
Predictably, there's been an enraged outcry from the renewable energy industry and green groups, and of course the opposition parties have seized the opportunity to attack the government's credibility on climate change policy. ("Hi Kettle, I'm Pot! My, you're a lovely black colour aren't you?")
Like many commentators I have great sympathy for the small business owners and employees who've been enjoying a surge in PV installation activity as a direct consequence of the PVRP and who are now dealing with a sudden drop in orders. Yet I do not necessarily agree that the PVRP should have been left as it was. Let me explain.
In the back of your mind you must always remember this: photovoltaic technology is really neat, but it's a long way from ideal. For starters, today's PV is generally more expensive than other renewables. And it only generates power while the Sun is shining brightly. No matter how many solar panels we install in this country we'll always have need for other energy systems which generate significant power for the other 16 hours per day.
As a rule, I was no fan of the former government. So hopefully it should get your attention when I say that the basic premise behind the PVRP was pretty sound. $150M was allocated over five years to encourage industry development and hence further R&D in PV technology - not to generate as much electricity as possible! Maybe they were forced into it, I don't know, but it was a sensible notion to invest public funds in a promising sector of the renewable energy industry. Unfortunately... they didn't follow through with a sensible rebate scheme for the distribution of those funds.
The PVRP previously offered a flat $4,000. Better than a kick in the teeth, but with PV systems starting at around $12K for an average output of 4kWh per day even that wasn't enough to spur a lot of interest. The "battlers" still couldn't afford it and the more well-off could get better rates of financial return from other forms of "investment". So last year, possibly reading the pre-election mood re climate change, they doubled the rebate to $8,000.
Well didn't that just open the floodgates. They halved the effective cost of an entry-level PV system, bringing it within the reach of middle Australia and making the financial payback time far more acceptable. The take-up rate exploded, "with 35% of all solar installed in eight years of the program occurring in the last six months." (Quote from ATA e-bulletin 19 May 2008).
Poor Mr Swan. Elected to government on the promise of leadership on climate change, faced with the economic necessity of slashing government spending, he had to deal with a PVRP that had gotten out of control and was burning through its multi-year budgetary allocation at an alarming rate. There were only two options: put the brakes on the rate at which money was being paid out (by lowering the amount per payment or limiting its availability) or let it continue to accelerate before slamming into a brick wall a little way down the track when the money runs out. Clearly the brick wall option would be catastrophic for the very PV industry which the program was intended to foster.
So the new management decided to slow the rate of payments by introducing a means test, in line with the general policy of targeting financial assistance to those who need it most. In my personal opinion, that was a reasonable thing to do. The biggest thing to criticise is that it's an all-or-nothing measure tacked on to what was a poorly-designed rebate scheme in the first place.
Just for the fun of it I'm going to do a separate post discussing the actual impact of the means test, how it might relate to the also-announced green loans scheme, and explore an alternate design for a PVRP means test.
To wrap up this one, though, I would ask you to keep looking at the bigger picture and reserve your final judgement on this government's climate change credibility until we see their response to the Garnaut review. The PVRP is something that was inherited and that, politically, had to be carefully managed. Failure to slow the rate of payout would have harmed the PV industry and been attacked by the opposition as financially irresponsible. Axing the scheme (presumably in favour of something better down the track) or reducing the rebate would have sparked a political feeding frenzy. It had to be maintained, but carefully.
The Minister for the Environment put it this way on ABC TV: "We've got programs out there... which will ensure there is enough demand in the Australian community in the long term to get solar panels on roofs... and to make sure that we continue to build a sustainable solar industry into the long term."
Mind you, the other climate change measures announced in the budget weren't terribly inspiring... my guess is it'll be another year, the post-Garnaut budget, before we know whether the promised leadership will be delivered. Let's keep up the pressure.
Monday 5 May 2008
Empty (stats update)
On the morning of the 29th March my rain gauge reported 13mm of rain had fallen in the previous 24 hours, and my tanks were full. In the intervening 37 days we have had just 11.5mm of additional rainfall and now the tanks are just about empty.
I've learned a few things. Like, my water level gauge is inaccurate: properly calibrated to indicate the "full" height, it reaches empty before the tanks do. That's OK, I can compensate for that in my calculations. I know that we've been using around 250L per day on average, and that full tanks would last 32 days at that rate. And now I need another 50mm or more of rain to fill them up again.
So the washing machine and toilet are getting switched back to mains water today. We'll use up whatever's left in the tank to fill the nappy soaking bucket.
In the meantime, here are our latest stats for mains water and electricity use over the past 16 days. We've had a guest for half of that which has pushed the water figure up a little.
Electricity: 7.81kWh per day (326W continuous)
Water: 207L per day
I've learned a few things. Like, my water level gauge is inaccurate: properly calibrated to indicate the "full" height, it reaches empty before the tanks do. That's OK, I can compensate for that in my calculations. I know that we've been using around 250L per day on average, and that full tanks would last 32 days at that rate. And now I need another 50mm or more of rain to fill them up again.
So the washing machine and toilet are getting switched back to mains water today. We'll use up whatever's left in the tank to fill the nappy soaking bucket.
In the meantime, here are our latest stats for mains water and electricity use over the past 16 days. We've had a guest for half of that which has pushed the water figure up a little.
Electricity: 7.81kWh per day (326W continuous)
Water: 207L per day
Saturday 19 April 2008
"Obscene" profiteering causing global starvation
Please take a few minutes - right now - to read Greenpa's post about the murderous impact of food market speculation on the world's poor and needy, and follow it up with an action.
I'm going to write to my member of parliament.
I'm going to write to my member of parliament.
"Greenwashing" concern re Solahart promotion
I just sent the following email to Solahart's Australian headquarters:
Hello,
Let me preface this by saying that I'm a very satisfied Solahart customer, having replaced my electric system just over six months ago and not wasted a single watt-hour of electricity on water heating ever since. However I was not so impressed with your company's recent marketing initiative involving a bumper sticker which reads, "My Solahart helps offset my car's CO2 emissions."
It surprised and disappointed me to have such a misleading environmental line come from a company which does an enormous amount of good through the promotion of renewable energy technology. Quite simply, that bumper sticker statement is false and potentially harmful.
The statement is false because solar water heaters do not remove CO2 from the atmosphere, directly or indirectly, and therefore cannot be counted as an "offset" against the burning of fossil fuels in a car engine. Instead, solar water heaters simply avoid the need to burn fossil fuels in power stations or in gas heaters. There is absolutely no relationship between solar hot water and vehicle emissions.
If the community truly believed the bumper sticker then they would feel less compelled to reduce their transport-related emissions in the false belief that they were somehow "offset" to some degree by their solar water heater.
Though it may have been an honest mistake or oversight, this promotion has the appearance of "greenwashing". At the very least, please cease the distribution of this bumper sticker immediately. I would also ask that you either send a follow-up retraction letter to all those who have already been sent a sticker (such as myself), or that you post such a retraction in a prominent place on your website or in another suitable public forum.
I would be more than happy to discuss these matters with you further - please feel free to reply via email or contact me on [phone number removed].
Sincerely,
Terry Brady
Bald Hills, Qld, Australia
http://2050vision.blogspot.com
Stats Update - now including tank water
Here are the latest stats for our electricity and town water consumption over the past 25 days, plus some new information on our tank water use.
Electricity consumption has increased again.
This period: 8kWh per day, or 333W continuous
Previous 21 days: 6.84 and 285
Average since start of year: 7.62 and 317.
Town water use is also up. I think it's largely my fault... love the hot showers in cooler weather. 189L/day vs 130 in the previous 21 days and 164 average since the start of the year.
I may have mentioned when I was planning my tank installation that I considered getting a water meter to measure how much water we pumped from the tanks. Well I didn't do that, but I did fit a water level gauge which shows the height of the water in increments of 10cm. I also bought a rain gauge at the start of February and started keeping records of daily rainfall, and I noted on which date my tank was last filled completely. I've observed that 1mm of rainfall causes a rise of 20mm in the tanks and I've calculated that 100mm of water in the tanks is very close to 800L.
Armed with all this information and the current gauge reading, I can estimate how much water we've used and when it's likely to run out. In the 21 days since last full the tank level has dropped from 110cm (full) to 70cm. Rainfall of 11mm has added about 22cm to the tanks, so we have extracted about 62cm in total. That works out to about 4960L, or 236L/day. At that rate we have enough water to last another 24 days without further rain and a full tank would give us 37 days supply in a dry spell.
What's startling here is the overall amount of water we're using... 189+236=425L/day. It's quite a bit more than before we had the pump installed but we aren't using any significant amount of water outside. That means we're using more inside.
The laundry has to be the main culprit. Once we had the washing machine hooked up to the tanks we started using cloth nappies for our infant instead of the evil but water-efficient disposables. So every day or two we now go through a big bucket of tank water for soaking and then an extra load of washing. Combine this with my slackening frugality in the shower and you would probably account for most of the roughly 100L/day increase compared with figures from six months ago.
Electricity consumption has increased again.
This period: 8kWh per day, or 333W continuous
Previous 21 days: 6.84 and 285
Average since start of year: 7.62 and 317.
Town water use is also up. I think it's largely my fault... love the hot showers in cooler weather. 189L/day vs 130 in the previous 21 days and 164 average since the start of the year.
I may have mentioned when I was planning my tank installation that I considered getting a water meter to measure how much water we pumped from the tanks. Well I didn't do that, but I did fit a water level gauge which shows the height of the water in increments of 10cm. I also bought a rain gauge at the start of February and started keeping records of daily rainfall, and I noted on which date my tank was last filled completely. I've observed that 1mm of rainfall causes a rise of 20mm in the tanks and I've calculated that 100mm of water in the tanks is very close to 800L.
Armed with all this information and the current gauge reading, I can estimate how much water we've used and when it's likely to run out. In the 21 days since last full the tank level has dropped from 110cm (full) to 70cm. Rainfall of 11mm has added about 22cm to the tanks, so we have extracted about 62cm in total. That works out to about 4960L, or 236L/day. At that rate we have enough water to last another 24 days without further rain and a full tank would give us 37 days supply in a dry spell.
What's startling here is the overall amount of water we're using... 189+236=425L/day. It's quite a bit more than before we had the pump installed but we aren't using any significant amount of water outside. That means we're using more inside.
The laundry has to be the main culprit. Once we had the washing machine hooked up to the tanks we started using cloth nappies for our infant instead of the evil but water-efficient disposables. So every day or two we now go through a big bucket of tank water for soaking and then an extra load of washing. Combine this with my slackening frugality in the shower and you would probably account for most of the roughly 100L/day increase compared with figures from six months ago.
Sunday 13 April 2008
Solar Tariff Tiff
There's a lot of noise being made at the moment about "feed-in tariffs", or bonus money paid to folks like me for energy that my new solar panels will feed in to the electricity grid. The debate centres around how to measure and price that energy. Here's my take.
There are two main kinds of benefit that large-scale distributed PV electric generation can potentially deliver to the community as a whole: environmental and financial.
The long-term environmental vision, which I'm sure most people would agree is the right idea, is for future society to be powered with cheap, clean, renewable energy instead of being dependent on the burning of coal or the fission of uranium which - even if the technology can be made "clean" - will both eventually run out. An essential feature of this vision is that we must become far more efficient in our use of the energy that is available.
And while it's obvious to most people that harvesting sunlight is sustainable and much cleaner than digging up and burning coal, not everybody is aware that having solar energy generation located nice and close to all our air conditioners is a great way to minimise infrastructure costs associated with peak demand and long-distance power transmission on hot afternoons.
A good feed-in tariff scheme for solar electricity would help to realise both kinds of benefit.
The Queensland Government appears to be following the South Australian lead in proposing a model under which I would only be paid a bonus for producing energy that was not simultaneously consumed within my own home. Just to be clear, that's excess energy which I produce but somebody else gets to use. This is broadly referred to as a "net tariff" scheme.
A number of groups, including the Local Power group through which I've ordered my panels, the Alternative Technology Association, Queensland Conservation, the Queensland Consumers Association and reportedly even BP (who make panels) are expressing disappointment in this and arguing instead for a "gross tariff" scheme whereby I would be paid a premium rate for all the energy produced by my panels regardless of how much energy I consume within my own home, or when. This is reportedly the model implemented in Germany, a world leader in terms of solar electricity generation capacity.
The motivation of the "gross tariff" advocates is fairly simple to understand.
Firstly, most of them genuinely want to see our society move as quickly as possible from fossil-fuel dependency to clean, renewable energy sources - which of course I agree with. Secondly, there's the financial self-interest: panel buyers want faster payback on their "investment" and higher long-term profitability while manufacturers like BP want to sell more panels. And thirdly we have an environmental loopback effect where making panels more financially attractive encourages greater adoption which takes us one step closer to having a clean, renewable energy infrastructure.
However, despite being both an "environmentalist" and a purchaser of solar panels, I don't agree that a gross tariff scheme is an obviously right choice for Queensland as a whole community.
In order to deliver on the environmental potential, the installation of solar panels must succeed in reducing the overall demand for energy from non-renewable sources. And in order to reduce costs associated with the grid infrastructure itelf, that energy must be delivered at times of peak demand. As I see it, the gross tariff schemes being proposed would actually erode both of those benefits from the inside, because it reduces the incentive for the owners of the panels to minimise their own energy consumption. Taken to the extreme, it provides an avenue for wealthy high energy users (and especially those addicted to their air conditioning) to cheaply maintain or even increase their energy consumption. I have actually had conversations with somebody who sees that kind of thing as an opportunity.
(Related post: Does energy efficiency encourage greater consumption?)
In contrast, the net tariff scheme put forward by the state is designed to reward those who find ways to minimise their consumption (delivering the environmental benefit), especially during those hot, sunny times when their panels are producing the most power (delivering the peak load infrastructure cost benefit).
Australian taxpayers are already contributing $8,000 towards my panels through a federal scheme to stimulate growth in the PV industry. Why should my fellow Queenslanders pay me even more in a subsidy which I could squander by simply using more energy and defeating the purpose of all that investment in the first place?
---
Speaking of the bigger picture, I believe that the actual core problem here is that current retail energy prices are much, much lower than the true cost of the energy. Government subsidies to the coal industry, myopic belief in unlimited growth and a very bad habit of completely ignoring "externalities" have made it so. Gross tariff proposals make a certain amount of sense in that they come closer to recognising the complete value of the energy, but the proper objectives of such a scheme would be continually undermined by the disincentive to reduce consumption.
Maybe as a kind of middle-ground policy it would make sense for panel owners to be paid a modest flat rate for their gross production on the proviso that they sourced at least the same quantity of energy (or 100% of their consumption, whichever is lower) from GreenPower-accredited providers. That would help to direct funding into renewable energy projects. Mind you, panel owners could achieve almost exactly the same thing by simply not selling their RECs at the time of installation. (See my earlier post on that topic.)
Perhaps surprisingly, I'm leaning towards opposing "time-of-day" metering for retail electricity consumption at this point. The idea behind it is to charge consumers more for energy consumed during peak periods. Sounds sensible enough, but apart from smoothing the load on the distribution grid it actually favours the coal generators and erodes the benefit of having a substantial PV capacity. However if it could be shown that time-of-day metering reduced overall energy consumption and especially consumption of fossil fuels then it might be worth doing.
But the "elephant in the room" (to borrow a phrase I once heard used by Andrew McNamara) which apparently nobody is talking about is that over the lifetime of any new solar panel installation the retail price of energy is likely to go up dramatically. You can thank climate change, carbon trading, peak oil and population growth for that. Even without any kind of tariffs, that rise should significantly shorten the effective payback time for a PV installation through avoided energy costs in the future.
There are two main kinds of benefit that large-scale distributed PV electric generation can potentially deliver to the community as a whole: environmental and financial.
The long-term environmental vision, which I'm sure most people would agree is the right idea, is for future society to be powered with cheap, clean, renewable energy instead of being dependent on the burning of coal or the fission of uranium which - even if the technology can be made "clean" - will both eventually run out. An essential feature of this vision is that we must become far more efficient in our use of the energy that is available.
And while it's obvious to most people that harvesting sunlight is sustainable and much cleaner than digging up and burning coal, not everybody is aware that having solar energy generation located nice and close to all our air conditioners is a great way to minimise infrastructure costs associated with peak demand and long-distance power transmission on hot afternoons.
A good feed-in tariff scheme for solar electricity would help to realise both kinds of benefit.
The Queensland Government appears to be following the South Australian lead in proposing a model under which I would only be paid a bonus for producing energy that was not simultaneously consumed within my own home. Just to be clear, that's excess energy which I produce but somebody else gets to use. This is broadly referred to as a "net tariff" scheme.
A number of groups, including the Local Power group through which I've ordered my panels, the Alternative Technology Association, Queensland Conservation, the Queensland Consumers Association and reportedly even BP (who make panels) are expressing disappointment in this and arguing instead for a "gross tariff" scheme whereby I would be paid a premium rate for all the energy produced by my panels regardless of how much energy I consume within my own home, or when. This is reportedly the model implemented in Germany, a world leader in terms of solar electricity generation capacity.
The motivation of the "gross tariff" advocates is fairly simple to understand.
Firstly, most of them genuinely want to see our society move as quickly as possible from fossil-fuel dependency to clean, renewable energy sources - which of course I agree with. Secondly, there's the financial self-interest: panel buyers want faster payback on their "investment" and higher long-term profitability while manufacturers like BP want to sell more panels. And thirdly we have an environmental loopback effect where making panels more financially attractive encourages greater adoption which takes us one step closer to having a clean, renewable energy infrastructure.
However, despite being both an "environmentalist" and a purchaser of solar panels, I don't agree that a gross tariff scheme is an obviously right choice for Queensland as a whole community.
In order to deliver on the environmental potential, the installation of solar panels must succeed in reducing the overall demand for energy from non-renewable sources. And in order to reduce costs associated with the grid infrastructure itelf, that energy must be delivered at times of peak demand. As I see it, the gross tariff schemes being proposed would actually erode both of those benefits from the inside, because it reduces the incentive for the owners of the panels to minimise their own energy consumption. Taken to the extreme, it provides an avenue for wealthy high energy users (and especially those addicted to their air conditioning) to cheaply maintain or even increase their energy consumption. I have actually had conversations with somebody who sees that kind of thing as an opportunity.
(Related post: Does energy efficiency encourage greater consumption?)
In contrast, the net tariff scheme put forward by the state is designed to reward those who find ways to minimise their consumption (delivering the environmental benefit), especially during those hot, sunny times when their panels are producing the most power (delivering the peak load infrastructure cost benefit).
Australian taxpayers are already contributing $8,000 towards my panels through a federal scheme to stimulate growth in the PV industry. Why should my fellow Queenslanders pay me even more in a subsidy which I could squander by simply using more energy and defeating the purpose of all that investment in the first place?
---
Speaking of the bigger picture, I believe that the actual core problem here is that current retail energy prices are much, much lower than the true cost of the energy. Government subsidies to the coal industry, myopic belief in unlimited growth and a very bad habit of completely ignoring "externalities" have made it so. Gross tariff proposals make a certain amount of sense in that they come closer to recognising the complete value of the energy, but the proper objectives of such a scheme would be continually undermined by the disincentive to reduce consumption.
Maybe as a kind of middle-ground policy it would make sense for panel owners to be paid a modest flat rate for their gross production on the proviso that they sourced at least the same quantity of energy (or 100% of their consumption, whichever is lower) from GreenPower-accredited providers. That would help to direct funding into renewable energy projects. Mind you, panel owners could achieve almost exactly the same thing by simply not selling their RECs at the time of installation. (See my earlier post on that topic.)
Perhaps surprisingly, I'm leaning towards opposing "time-of-day" metering for retail electricity consumption at this point. The idea behind it is to charge consumers more for energy consumed during peak periods. Sounds sensible enough, but apart from smoothing the load on the distribution grid it actually favours the coal generators and erodes the benefit of having a substantial PV capacity. However if it could be shown that time-of-day metering reduced overall energy consumption and especially consumption of fossil fuels then it might be worth doing.
But the "elephant in the room" (to borrow a phrase I once heard used by Andrew McNamara) which apparently nobody is talking about is that over the lifetime of any new solar panel installation the retail price of energy is likely to go up dramatically. You can thank climate change, carbon trading, peak oil and population growth for that. Even without any kind of tariffs, that rise should significantly shorten the effective payback time for a PV installation through avoided energy costs in the future.
Thursday 13 March 2008
Discuss: growing food in cities, and using the internet to learn how
During the course of my work this week I had reason to visit a school in north-eastern New South Wales. That region has a reputation for attracting and fostering people with "alternative" views and values, particularly in regard to environmental protection and sustainable living. So it was that one of the teachers, knowing beforehand that I publish this blog, introduced me to a student who has a keen interest in permaculture and who is also active in a group centred around the Transition Towns concept (see link in my "highly recommended" sidebar).
Now, not that this blog has a huge world-wide audience or anything, I would like to give that student the opportunity to remain anonymous but at the same time see if I can't get a bit of discussion going here around a couple of the ideas that have come to mind as a result of our meeting.
I put that TT link over there ages ago and haven't looked at their site in months. I think they're clearly world leaders, forging a path to the future. What I'm not so sure about is how to make that path into a highway wide enough to take the cities along with the towns. I should revisit their site and see if there's been any progress on that subject.
One of the obvious things (to me) is that people in cities will need to grow food for themselves and their immediate community. More than that, they'll need to do so sustainably, recycling nutrients in efficient closed loops and doing it all with an absolute minimum of external energy inputs. In other words we need permaculture cities. Unfortunately the vast majority of city dwellers know nothing about growing anything.
Take me as an example: I have a borrowed copy of the 2nd edition of "Introduction to Permaculture" and recently bought the Digger's Club's "Australian Fruit & Vegetable Garden". I've been experimenting in the back yard for the past year or so, but so far have very little to show (or eat) as a result.
So, you thus-far anonymous student, if you're looking for school project ideas that combine IT with permaculture, you might consider starting an online library of training/instructional podcasts or other resources to help city folk like me with no horticultural knowledge transform our backyards and balconies into productive, sustainable food gardens. Seriously - was there ever a period in history prior to the present day where an entire generation of a civilisation had no idea how to grow their own food? We need that knowledge back again, and the internet provides a platform unlike anything else in human history for the distribution of knowledge.
The internet might well be our best defence against falling into another dark age as oil production falls. We stand to lose a great deal of our personal mobility. It just won't be feasible for people like me to travel hundreds of kilometers in a single day just to provide some brief specialist service. But if we can maintain and build on our communications infrastructure and the library of publicly-accessible knowledge then the physical isolation won't necessarily be a barrier to skills and ideas.
What I would like to do now is to invite you all to hit the comments and have a bit of a discussion about those two ideas and their intersection. Will city people need to grow their own food in the future? Can the internet be used effectively to deliver training in the essential garden skills and design principles? If you're a city person, what kind of online resources do you think would help you? If you're a gardening guru, how could you best capture and share what you have learned?
Now, not that this blog has a huge world-wide audience or anything, I would like to give that student the opportunity to remain anonymous but at the same time see if I can't get a bit of discussion going here around a couple of the ideas that have come to mind as a result of our meeting.
I put that TT link over there ages ago and haven't looked at their site in months. I think they're clearly world leaders, forging a path to the future. What I'm not so sure about is how to make that path into a highway wide enough to take the cities along with the towns. I should revisit their site and see if there's been any progress on that subject.
One of the obvious things (to me) is that people in cities will need to grow food for themselves and their immediate community. More than that, they'll need to do so sustainably, recycling nutrients in efficient closed loops and doing it all with an absolute minimum of external energy inputs. In other words we need permaculture cities. Unfortunately the vast majority of city dwellers know nothing about growing anything.
Take me as an example: I have a borrowed copy of the 2nd edition of "Introduction to Permaculture" and recently bought the Digger's Club's "Australian Fruit & Vegetable Garden". I've been experimenting in the back yard for the past year or so, but so far have very little to show (or eat) as a result.
So, you thus-far anonymous student, if you're looking for school project ideas that combine IT with permaculture, you might consider starting an online library of training/instructional podcasts or other resources to help city folk like me with no horticultural knowledge transform our backyards and balconies into productive, sustainable food gardens. Seriously - was there ever a period in history prior to the present day where an entire generation of a civilisation had no idea how to grow their own food? We need that knowledge back again, and the internet provides a platform unlike anything else in human history for the distribution of knowledge.
The internet might well be our best defence against falling into another dark age as oil production falls. We stand to lose a great deal of our personal mobility. It just won't be feasible for people like me to travel hundreds of kilometers in a single day just to provide some brief specialist service. But if we can maintain and build on our communications infrastructure and the library of publicly-accessible knowledge then the physical isolation won't necessarily be a barrier to skills and ideas.
What I would like to do now is to invite you all to hit the comments and have a bit of a discussion about those two ideas and their intersection. Will city people need to grow their own food in the future? Can the internet be used effectively to deliver training in the essential garden skills and design principles? If you're a city person, what kind of online resources do you think would help you? If you're a gardening guru, how could you best capture and share what you have learned?
Wednesday 12 March 2008
Tuesday 11 March 2008
Queenslanders receive cash incentive to tackle climate change
Update 13/4: Most of what I wrote in this post still makes sense, except that the actual model proposed by the government is slightly different to what I though it was. See today's post for more detail.
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Great headline, huh? I can't claim credit for it - somebody in the Premier's Office came up with that one to catch the media's attention for today's press release about feed-in tariffs for private solar electricity generation. (Thanks to Ian for pointing that one out to me.)
Like most government statements there's enough spin there to make you dizzy just looking at it. The goods news is that behind the bluster is some really good policy. And a catch, of course.
The announcement lauds the Queensland government's decision to "pay households and business 44 cents for every kilowatt-hour generated from solar power systems at work and at home and fed into the grid." At first glance it sounds like every panel on every roof suddenly becomes a great money-spinner. However you need to read carefully into the definition of "fed into the grid." In the context of the rest of the release it becomes clear that the 44c rate applies only to any additional energy produced by the panels in excess of the energy consumed by the household or business. Your panels have to make more energy than you use before the government (or utilities) spend a cent.
You'd know by now that I'm quite proud of my home's energy efficiency. Our bill just arrived confirming our consumption for the quarter at 7.8kWh per day. (By comparison, Australian government figures I found via Google seem to suggest that the average Aussie household uses around 18, and some friends of ours just got hit with a bill for something in the vicinity of 50kWh per day.) To produce enough energy to meet all of my own needs in a year, I would need to install a 2kW (peak output) array which is estimated to produce almost exactly 8kWh per day on average. Even with the discount negotiated by the Local Power buying group and the federal govt's eight grand rebate I'd be looking at an investment of around $11,000 just to get my quarterly bill down to zero!
If I wanted to actually get some of the 44c/kWh action I'd need to install an even larger 3kW array - an additional investment of 7 thousand for a yearly return of around $650. Premier Bligh's offer doesn't sound quite so generous now, does it?
So I need to explain why I said at the top of this that it's "really good policy". Thankfully the explanation is simple: this policy promotes interest and investment in renewable energy infrastructure, but more importantly it provides a strong incentive to increase efficiency and reduce demand in order to get household or business consumption down below the capacity of smaller PV systems which are presently affordable thanks to the federal government's $8K rebate scheme. For myself, I'll be taking the 4kWh per day threshold as a personal challenge.
Though I may have to wait until the kids leave home before that becomes feasible. Good thing the feed-in tariff legislation announced today is guaranteed for 20 years.
---
Great headline, huh? I can't claim credit for it - somebody in the Premier's Office came up with that one to catch the media's attention for today's press release about feed-in tariffs for private solar electricity generation. (Thanks to Ian for pointing that one out to me.)
Like most government statements there's enough spin there to make you dizzy just looking at it. The goods news is that behind the bluster is some really good policy. And a catch, of course.
The announcement lauds the Queensland government's decision to "pay households and business 44 cents for every kilowatt-hour generated from solar power systems at work and at home and fed into the grid." At first glance it sounds like every panel on every roof suddenly becomes a great money-spinner. However you need to read carefully into the definition of "fed into the grid." In the context of the rest of the release it becomes clear that the 44c rate applies only to any additional energy produced by the panels in excess of the energy consumed by the household or business. Your panels have to make more energy than you use before the government (or utilities) spend a cent.
You'd know by now that I'm quite proud of my home's energy efficiency. Our bill just arrived confirming our consumption for the quarter at 7.8kWh per day. (By comparison, Australian government figures I found via Google seem to suggest that the average Aussie household uses around 18, and some friends of ours just got hit with a bill for something in the vicinity of 50kWh per day.) To produce enough energy to meet all of my own needs in a year, I would need to install a 2kW (peak output) array which is estimated to produce almost exactly 8kWh per day on average. Even with the discount negotiated by the Local Power buying group and the federal govt's eight grand rebate I'd be looking at an investment of around $11,000 just to get my quarterly bill down to zero!
If I wanted to actually get some of the 44c/kWh action I'd need to install an even larger 3kW array - an additional investment of 7 thousand for a yearly return of around $650. Premier Bligh's offer doesn't sound quite so generous now, does it?
So I need to explain why I said at the top of this that it's "really good policy". Thankfully the explanation is simple: this policy promotes interest and investment in renewable energy infrastructure, but more importantly it provides a strong incentive to increase efficiency and reduce demand in order to get household or business consumption down below the capacity of smaller PV systems which are presently affordable thanks to the federal government's $8K rebate scheme. For myself, I'll be taking the 4kWh per day threshold as a personal challenge.
Though I may have to wait until the kids leave home before that becomes feasible. Good thing the feed-in tariff legislation announced today is guaranteed for 20 years.
Sunday 9 March 2008
Can't have your solar power cake and eat it too
Let me first give kudos to the people behind Local Power, a community-based buying group which is helping to bring a chunk of new solar electricity generation online. I applaud their initiative, commitment and professionalism. More than that, though, I've paid them a deposit to have a 1kW photovoltaic array installed on my own roof.
Curiously, following on the heels of the high levels of public interest in what this group has done, the Queensland government has announced that it will offer a similar kind of service in order to facilitate the installation of a thousand PV systems on roofs in the "sunshine state" at a reduced price. Note they're not actually providing funds for the gear - just the administrative service that's required to coordinate a bulk purchase and therefore a cheaper per-unit price.
I'll leave my thoughts about the significance and value of PV in the grand scheme of things for another post. For this one I want to focus on a tricky little aspect which green-minded solar panel buyers will need to be aware of. (The particulars are likely to vary in different situations but what I'm writing here is what I understand will apply to me. I'll edit and/or post again if I need to.)
Both the Local Power and Qld government schemes are for "grid-connected" solar photovoltaic electricity generating systems. The systems include an inverter which takes the low-voltage DC power from the panels and transforms it into 240V AC power that gets fed into the electricity grid. There's a dedicated meter which measures how much power your system has supplied to the grid, separate from the one you already have which measures how much power you consume in the running of your home.
Hypothetically, let's say that in some future 3 month period my home consumes 675kWh of energy and my panels supply 360kWh to the grid. As I understand it, when I get my electric utility bill I will see the readings for both meters. Normally Tariff 1 costs about 15.5c per kWh so without the panels I'd be charged about $105 for my energy. But with the panels producing power I get recognition for their contribution with a simple deduction from my Tariff 11 consumption. The nett use would be 315kWh at around $49.
Woohoo! My investment in panels has not only saved me money, but reduced my dependence on fossil fuels by 360kWh this quarter! I can sure feel proud of myself now, having invested in environmental protection and sustainability.
But wait a moment. I might be badly mistaken about my green energy credentials.
You see, most of the time when a PV system like this gets installed, the buyer signs a little bit of paper in return for an extra discount on the up-front cost. The amount of the discount varies but as an example the system I've ordered might be discounted by somewhere between $315 and $819. Neat, huh? How nice of the government to give me a bit of an extra bonus for investing in clean energy.
Listen up: this is not a bonus. This is not free money. The form that you are offered to sign is one which transfers your right to claim the "cleanness" of the energy your panels will produce over their lifetime to another party. You are paid market price for your Renewable Energy Certificates, or "RECs" as they are known. One REC is equivalent to one megawatt-hour (MWh) of renewable power. These RECs represent the legal right of the holder to claim that the power they used (or sold to somebody else) was clean. And if you signed that paper, you don't have them any more.
So in the case of my hypothetical electricity bill, though I do enjoy a financial benefit, every one of the 675kWh of energy that I consumed must have been supplied to the grid by coal-fired power stations! If I wanted to have a clear conscience about my energy use I'd still have to opt in for 675kWh of 100% certified GreenPower. In effect I would have to pay a bit extra each quarter to buy a portion of my own original RECs back again.
I hope that's not too confusing. Just to repeat: by selling my RECs when the system was installed, I gave up the right to claim the cleanliness of the energy my system produces. Though I get a financial benefit for the energy produced by the system over time, I would still have to opt in to GreenPower schemes for the entire amount of my personal energy consumption if I want to eliminate my dependence on dirty power generators.
It's worth pointing out that you're in no way obliged to sell your RECs. You can either hold on to them with a view to eventually selling them (during which time you would have to pay the GreenPower surcharge since you're intending to give up your right to the cleanliness of your panels' energy sometime in the future) or your can ignore the whole scheme entirely and just consider all of that clean energy to be yours for as long as you're using the panels. Whatever you do, there's a bit of a gamble and speculation involved and most of us don't have the time nor skill to track and trade these things to our financial benefit.
So if you do sign up for one of these systems - which I would generally applaud even though I think PV is only a tiny part of the overall solution to our energy and climate crisis - please be aware of the significance of the RECs scheme and what it means to sell those certificates. Otherwise you might end up being more dependent on fossil fuels than you hoped you would be, without even realising it.
Curiously, following on the heels of the high levels of public interest in what this group has done, the Queensland government has announced that it will offer a similar kind of service in order to facilitate the installation of a thousand PV systems on roofs in the "sunshine state" at a reduced price. Note they're not actually providing funds for the gear - just the administrative service that's required to coordinate a bulk purchase and therefore a cheaper per-unit price.
I'll leave my thoughts about the significance and value of PV in the grand scheme of things for another post. For this one I want to focus on a tricky little aspect which green-minded solar panel buyers will need to be aware of. (The particulars are likely to vary in different situations but what I'm writing here is what I understand will apply to me. I'll edit and/or post again if I need to.)
Both the Local Power and Qld government schemes are for "grid-connected" solar photovoltaic electricity generating systems. The systems include an inverter which takes the low-voltage DC power from the panels and transforms it into 240V AC power that gets fed into the electricity grid. There's a dedicated meter which measures how much power your system has supplied to the grid, separate from the one you already have which measures how much power you consume in the running of your home.
Hypothetically, let's say that in some future 3 month period my home consumes 675kWh of energy and my panels supply 360kWh to the grid. As I understand it, when I get my electric utility bill I will see the readings for both meters. Normally Tariff 1 costs about 15.5c per kWh so without the panels I'd be charged about $105 for my energy. But with the panels producing power I get recognition for their contribution with a simple deduction from my Tariff 11 consumption. The nett use would be 315kWh at around $49.
Woohoo! My investment in panels has not only saved me money, but reduced my dependence on fossil fuels by 360kWh this quarter! I can sure feel proud of myself now, having invested in environmental protection and sustainability.
But wait a moment. I might be badly mistaken about my green energy credentials.
You see, most of the time when a PV system like this gets installed, the buyer signs a little bit of paper in return for an extra discount on the up-front cost. The amount of the discount varies but as an example the system I've ordered might be discounted by somewhere between $315 and $819. Neat, huh? How nice of the government to give me a bit of an extra bonus for investing in clean energy.
Listen up: this is not a bonus. This is not free money. The form that you are offered to sign is one which transfers your right to claim the "cleanness" of the energy your panels will produce over their lifetime to another party. You are paid market price for your Renewable Energy Certificates, or "RECs" as they are known. One REC is equivalent to one megawatt-hour (MWh) of renewable power. These RECs represent the legal right of the holder to claim that the power they used (or sold to somebody else) was clean. And if you signed that paper, you don't have them any more.
So in the case of my hypothetical electricity bill, though I do enjoy a financial benefit, every one of the 675kWh of energy that I consumed must have been supplied to the grid by coal-fired power stations! If I wanted to have a clear conscience about my energy use I'd still have to opt in for 675kWh of 100% certified GreenPower. In effect I would have to pay a bit extra each quarter to buy a portion of my own original RECs back again.
I hope that's not too confusing. Just to repeat: by selling my RECs when the system was installed, I gave up the right to claim the cleanliness of the energy my system produces. Though I get a financial benefit for the energy produced by the system over time, I would still have to opt in to GreenPower schemes for the entire amount of my personal energy consumption if I want to eliminate my dependence on dirty power generators.
It's worth pointing out that you're in no way obliged to sell your RECs. You can either hold on to them with a view to eventually selling them (during which time you would have to pay the GreenPower surcharge since you're intending to give up your right to the cleanliness of your panels' energy sometime in the future) or your can ignore the whole scheme entirely and just consider all of that clean energy to be yours for as long as you're using the panels. Whatever you do, there's a bit of a gamble and speculation involved and most of us don't have the time nor skill to track and trade these things to our financial benefit.
So if you do sign up for one of these systems - which I would generally applaud even though I think PV is only a tiny part of the overall solution to our energy and climate crisis - please be aware of the significance of the RECs scheme and what it means to sell those certificates. Otherwise you might end up being more dependent on fossil fuels than you hoped you would be, without even realising it.
Stats Update
For the two weeks to 4th March:
Electricity averaging 7.51kWh per day (313W continuous)
Water averaging 188L per day
Averages for the quarter since Dec 28 are 7.72kWh (322 continuous) and 165L.
Electricity averaging 7.51kWh per day (313W continuous)
Water averaging 188L per day
Averages for the quarter since Dec 28 are 7.72kWh (322 continuous) and 165L.
Starting again, though not from scratch
It was about a year ago that I first became seriously concerned about the environment and the sustainability of human civilisation. For about six months my energy and activity built up, then they plateaued and eventually waned over summer. Now here we are approaching the March equinox and I think things are on the up again. I'm totally out of phase. Maybe I should live in the northern hemisphere.
In the latter part of last year I came into a bit of extra money. It was enough to offer lots of interesting possibilities, but not so much that I didn't have to think carefully about what I'd do with it. I kept a chunk of it in reserve in case the appalling mosquito plague of the previous summer repeated itself, in which case I'd have invested in a gizmo to help make going outdoors a less hazardous proposition. But thankfully summer was mild and the mozzies were less than awful and so the funds stayed in my bank account.
Over the same period though, my gardening and composting efforts pretty much stopped. I got the overflow from the south tank connected up to the street, and I ripped up four old sleepers and a previous owner's intricate irrigation system in preparation for a backyard renovation... but that was about it. The compost pile has had no turning or tending. And yesterday I found that my mulch heap has become home for cane toads and termites! That's going to be a challenge to sort out. But anyway...
Pragmatically speaking, living in a city and having a sporadically time-demanding job as I do, I can't guarantee regular time to devote to gardening during the week. So I need to be smart about the way I set things up and to make use of systems and solutions which don't require a lot of maintenance.
Realising this, I've finally given in and used my stash of cash to purchase a fancy compost bin to take over duty from the simple open-bottomed thin-walled mouse-eaten black plastic box I've been using up until now. I put it on a base of four large pavers sited nearer the back door so hopefully it'll be less inviting and accessible to the furry little bastards, and adding things to it in the evenings should be less of an, um, "adventure".
I have to say, though, that as I set about giving my new bin a good feed of starting materials I was rather impressed with the quality of the compost in the bottom of the old black bin. It was made from a huge pile of woody weeds, a large dose of hedge trimmings and half a dozen or so 4-litre buckets of already-putrefying kitchen scraps irregularly thrown in on top. After removing some of the sticks and stalks and chunks of onion, what I was left with pretty much fit the descriptions of good compost that you read in books: dark brown, spongy, slightly moist, little odour. About ten centimetres of that has gone in to the bottom of the new bin to hopefully give the thing a good kick-start.
And along with that I'm hoping to restart my gardening efforts. In the past year or so I've failed to grow heaps of things, but I've learned a fair bit along the way and am ready to have another go. In truth it's a little out of character for me to show that kind of long-term persistence. Sadly, though, the signs are increasingly suggesting that a backyard garden is going to be an invaluable asset in years to come.
In the latter part of last year I came into a bit of extra money. It was enough to offer lots of interesting possibilities, but not so much that I didn't have to think carefully about what I'd do with it. I kept a chunk of it in reserve in case the appalling mosquito plague of the previous summer repeated itself, in which case I'd have invested in a gizmo to help make going outdoors a less hazardous proposition. But thankfully summer was mild and the mozzies were less than awful and so the funds stayed in my bank account.
Over the same period though, my gardening and composting efforts pretty much stopped. I got the overflow from the south tank connected up to the street, and I ripped up four old sleepers and a previous owner's intricate irrigation system in preparation for a backyard renovation... but that was about it. The compost pile has had no turning or tending. And yesterday I found that my mulch heap has become home for cane toads and termites! That's going to be a challenge to sort out. But anyway...
Pragmatically speaking, living in a city and having a sporadically time-demanding job as I do, I can't guarantee regular time to devote to gardening during the week. So I need to be smart about the way I set things up and to make use of systems and solutions which don't require a lot of maintenance.
Realising this, I've finally given in and used my stash of cash to purchase a fancy compost bin to take over duty from the simple open-bottomed thin-walled mouse-eaten black plastic box I've been using up until now. I put it on a base of four large pavers sited nearer the back door so hopefully it'll be less inviting and accessible to the furry little bastards, and adding things to it in the evenings should be less of an, um, "adventure".
I have to say, though, that as I set about giving my new bin a good feed of starting materials I was rather impressed with the quality of the compost in the bottom of the old black bin. It was made from a huge pile of woody weeds, a large dose of hedge trimmings and half a dozen or so 4-litre buckets of already-putrefying kitchen scraps irregularly thrown in on top. After removing some of the sticks and stalks and chunks of onion, what I was left with pretty much fit the descriptions of good compost that you read in books: dark brown, spongy, slightly moist, little odour. About ten centimetres of that has gone in to the bottom of the new bin to hopefully give the thing a good kick-start.
And along with that I'm hoping to restart my gardening efforts. In the past year or so I've failed to grow heaps of things, but I've learned a fair bit along the way and am ready to have another go. In truth it's a little out of character for me to show that kind of long-term persistence. Sadly, though, the signs are increasingly suggesting that a backyard garden is going to be an invaluable asset in years to come.
Saturday 23 February 2008
Does energy efficiency encourage greater consumption?
My initial encounter with the work of Amory Lovins was everything he intended it to be: persuasive, compelling and inspiring. After watching his lectures it just seemed obvious that we should all be taking energy efficiency to the extreme in order to save heaps of money - not to mention the planet.
Googling about for a bit more info and context, though, it wasn't long before I came across some Lovins hatin'. This piece is a prime example. (The one I linked to - not the one you're reading now!) I know very little about the author, Bryce, and would have to agree with him when it comes to what I believe is the false hope in biofuels, but I really took issue with the last part of his essay where he recalls the work of a long-dead Briton:
Jevons' postulate is based on at least two assumptions: that the available supply of energy will continue to grow over time, and that demand for the service that the energy provides is also unlimited. Think about the context of the early 1800's for a minute, as the industrial revolution was ramping up.
I'm no economist, but I have a notion that around that point in history the main constraint on economic growth was labour productivity - ie how much raw material could be processed by the human (and I guess animal) workforce. Then suddenly, with the invention of the steam engine, the amount of material which could be processed under the direction of one person dramatically increased. Instead of energy from food being applied through muscle, we had energy from wood, coal and other combustibles being applied through machinery.
I don't know exactly what happened, but it seems reasonable to think that the take-up of the new technology would have initially been constrained by high up-front costs, high ongoing costs in terms of fuel and maintenance and the need to train operators. You can also imagine that due to simple economies of scale - and the seemingly unlimited abundance of fossil fuels waiting to be dug out of the ground - both the up-front and ongoing costs would have trended downwards in reasonably quick time.
As that happened, the unit cost of production fell, making a whole range of goods affordable to people who never could have afforded them in the past. A vast reserve of energy converged with a vast reserve of market demand and the end result is the energy-squandering consumerist culture we have today. Any increase in energy efficiency during the time from then until now would simply have lowered production cost and therefore met with increased demand which in turn increased overall energy consumption.
But I suspect that era is rapidly coming to an end.
For starters, we are now seeing constraints on energy availability every way we turn. Even if it weren't for the fact that we've consumed such a large portion of the planet's fossil fuel stores, the greenhouse effect is imposing a major restriction on our use of what remains. Practical, environmental and security concerns get in the way of a rapid expansion of the nuclear power industry. What's left is a smattering of accessible geothermal resources and true renewables like wind, solar and wave energy. For these reasons, I think that energy availability may become the primary constraint on the economy. Increasing energy-efficiency then becomes a pre-requisite for economic growth... but overall energy consumption will be constrained on the supply side. So the first of Jevons' assumptions is no longer true.
The other assumption - that the market will respond to increases in efficiency by simply using more of the service - is more subtle. Let's have another look at what Bryce had to say:
Getting back to Amory Lovins, though, air conditioning is a great point on which to end this post. You see, Lovins doesn't just advocate ongoing marginal improvements to the efficiency of air conditioners and cars. His vision is to design buildings that don't need to use energy to keep them cool, making the air conditioner pretty much obsolete in the process; to make cars which are so light and efficient (while also being roomy, strong and safe) that they can reasonably be powered by solar-generated electricity or a few handfuls of biofuel.
While it's true that our energy supplies are tightening up, the work of guys like Lovins means that there's the opportunity for improving the quality of life by continually learning to do more with less.
Googling about for a bit more info and context, though, it wasn't long before I came across some Lovins hatin'. This piece is a prime example. (The one I linked to - not the one you're reading now!) I know very little about the author, Bryce, and would have to agree with him when it comes to what I believe is the false hope in biofuels, but I really took issue with the last part of his essay where he recalls the work of a long-dead Briton:
The final – and most important – area in which Lovins has been consistently wrong is his claim that efficiency lowers energy consumption. And when it comes to arguing the merits of energy efficiency, Lovins’s prime nemesis is a dead guy – William Stanley Jevons – a British economist who in 1865 determined that increased efficiency won’t cut energy use, it will raise it. “It is wholly a confusion of ideas to suppose that the economical use of fuels is equivalent to a diminished consumption. The very contrary is the truth.” And in the 142 years since Jevons put forth that thesis, now commonly known as the Jevons Paradox, he’s yet to be proven wrong.It shocked and dismayed me at first. Now, after some consideration, I'm convinced that argument is fundamentally flawed when applied to the present day circumstances.
Jevons' postulate is based on at least two assumptions: that the available supply of energy will continue to grow over time, and that demand for the service that the energy provides is also unlimited. Think about the context of the early 1800's for a minute, as the industrial revolution was ramping up.
I'm no economist, but I have a notion that around that point in history the main constraint on economic growth was labour productivity - ie how much raw material could be processed by the human (and I guess animal) workforce. Then suddenly, with the invention of the steam engine, the amount of material which could be processed under the direction of one person dramatically increased. Instead of energy from food being applied through muscle, we had energy from wood, coal and other combustibles being applied through machinery.
I don't know exactly what happened, but it seems reasonable to think that the take-up of the new technology would have initially been constrained by high up-front costs, high ongoing costs in terms of fuel and maintenance and the need to train operators. You can also imagine that due to simple economies of scale - and the seemingly unlimited abundance of fossil fuels waiting to be dug out of the ground - both the up-front and ongoing costs would have trended downwards in reasonably quick time.
As that happened, the unit cost of production fell, making a whole range of goods affordable to people who never could have afforded them in the past. A vast reserve of energy converged with a vast reserve of market demand and the end result is the energy-squandering consumerist culture we have today. Any increase in energy efficiency during the time from then until now would simply have lowered production cost and therefore met with increased demand which in turn increased overall energy consumption.
But I suspect that era is rapidly coming to an end.
For starters, we are now seeing constraints on energy availability every way we turn. Even if it weren't for the fact that we've consumed such a large portion of the planet's fossil fuel stores, the greenhouse effect is imposing a major restriction on our use of what remains. Practical, environmental and security concerns get in the way of a rapid expansion of the nuclear power industry. What's left is a smattering of accessible geothermal resources and true renewables like wind, solar and wave energy. For these reasons, I think that energy availability may become the primary constraint on the economy. Increasing energy-efficiency then becomes a pre-requisite for economic growth... but overall energy consumption will be constrained on the supply side. So the first of Jevons' assumptions is no longer true.
The other assumption - that the market will respond to increases in efficiency by simply using more of the service - is more subtle. Let's have another look at what Bryce had to say:
While it’s true that improvements in energy efficiency on a microeconomic level – like replacing an old inefficient air conditioner with a newer high efficiency one – will cut consumption for that one location, when that same effort is spread over a macro scale the overall energy savings are usually swamped by overall increases in consumption. Thus the installation of more efficient air conditioners across an entire city or state, or country, allows people to use their air conditioners more and, since the cost of cooling suddenly becomes more affordable, more people install air conditioning.OK, that makes sense. It's probably reasonable to say that humanity will find some way to use all of the available energy and there will also be continuing demand for more. But with energy becoming less available, a balance is likely to be found.
Getting back to Amory Lovins, though, air conditioning is a great point on which to end this post. You see, Lovins doesn't just advocate ongoing marginal improvements to the efficiency of air conditioners and cars. His vision is to design buildings that don't need to use energy to keep them cool, making the air conditioner pretty much obsolete in the process; to make cars which are so light and efficient (while also being roomy, strong and safe) that they can reasonably be powered by solar-generated electricity or a few handfuls of biofuel.
While it's true that our energy supplies are tightening up, the work of guys like Lovins means that there's the opportunity for improving the quality of life by continually learning to do more with less.
Tuesday 19 February 2008
Fad or Fundament?
Have you noticed that the world is changing fast? For once I'm not talking about the biosphere - it's human society and politics I mean. Words based on "environment" and "sustainable" are starting to pervade the mass media, turning up in just about every political message at all levels of government and peppered through corporate communications. Advertising budgets are increasingly being spent on pointing out the "green" attributes of some product or service.
It seems that environmental groups have succeeded in using the greenhouse effect as a kind of lever to shift the massive inertia of social consciousness and direct it towards the long-term liveability of this planet. And the result has not just been all talk.
There are some great local examples, starting with the response to the water shortage of recent years. Not only have the residents of south-east Queensland succeeded in reducing their average per-capita consumption to one of the lowest rates in the developed world, we've maintained that discipline even with the rain of the past two months more than doubling the amount of water in our dams. Moreover, the sentiment of the majority of people I've spoken to is in line with official policy which says that conservative water use has become a permanent feature of life in this region!
Continuing with the theme of sustainable water use, one of the two main candidates standing for election to the office of Lord Mayor of Brisbane in a few weeks time is making a very big deal of his policies for minimising water wastage from leaking pipes and increasing the rebates for people who connect rainwater tanks for internal use in the home.
On the other side of politics, the incumbent mayor is earning a rare cheer from me for the spirit behind his latest announcement of funding to assist residents equip their homes with instantaneous energy meters of the type I've written about here in the past. I'm not totally thrilled with that particular approach (I'd rather see a loan/rent scheme) but I am thrilled with the stated objective of reducing the city's electricity consumption.
Both candidates are straining to one-up each other when it comes to public transport. Brisbane isn't large enough to have any direct control over railways but the next few years appear certain to see a very large number of new natural-gas powered buses on the city's roads and an expansion of the CityCat ferry fleet. Mr Incumbent is also touting a spending spree on bicycle paths and facilities.
I offer these examples as evidence of a major and accelerating shift in the public awareness of and concern for sustainability. I've written in the past about my belief that changing values is what brings about changes in behaviour, and I'm starting to become hopeful that values are indeed shifting in the right direction. Heck, I've even listened to speeches from federal parliament this week exhorting the nation to embrace the aboriginal peoples' attitude towards "the land", seeing oneself as literally a part of the environment and being always mindful of the need to care for it.
The question is whether this "trend" will continue. Are we really witnessing the early stages of the transformation of our wasteful, destructive, economically and ecologically irrational society into a responsible, efficient, ecologically-integrated civilisation with advanced culture and traditional wisdom as well as high technology? Well I hope so... because that's what it's probably going to take to avoid catastrophe.
So here's a litmus test for us to monitor our progress as a nation. The Australian Bureau of Agricultural and Resource Economics (ABARE) published a report in December 2007 which predicts that, on the basis of the policies and trends in effect at that time, Australia's energy use will grow by 1.6% per year through to 2030 (that's up about 44% compared to today) with around 92% of that energy being sourced from fossil fuels. Let me suggest that if these projections match our future reality, then we're in very big trouble. But...
If society is in fact changing, embracing values of sustainability, we will necessarily see our energy use grow by a smaller amount than predicted and possibly even declining by 2030. We must also see an major decrease in the proportion of our energy derived from fossil fuels. I'll be keep an eye out for future releases like this one from ABARE to see where we're headed.
In the meantime, we all need to support those politicians who are promoting reduced energy consumption, increased efficiency and a transition to renewable energy sources.
It seems that environmental groups have succeeded in using the greenhouse effect as a kind of lever to shift the massive inertia of social consciousness and direct it towards the long-term liveability of this planet. And the result has not just been all talk.
There are some great local examples, starting with the response to the water shortage of recent years. Not only have the residents of south-east Queensland succeeded in reducing their average per-capita consumption to one of the lowest rates in the developed world, we've maintained that discipline even with the rain of the past two months more than doubling the amount of water in our dams. Moreover, the sentiment of the majority of people I've spoken to is in line with official policy which says that conservative water use has become a permanent feature of life in this region!
Continuing with the theme of sustainable water use, one of the two main candidates standing for election to the office of Lord Mayor of Brisbane in a few weeks time is making a very big deal of his policies for minimising water wastage from leaking pipes and increasing the rebates for people who connect rainwater tanks for internal use in the home.
On the other side of politics, the incumbent mayor is earning a rare cheer from me for the spirit behind his latest announcement of funding to assist residents equip their homes with instantaneous energy meters of the type I've written about here in the past. I'm not totally thrilled with that particular approach (I'd rather see a loan/rent scheme) but I am thrilled with the stated objective of reducing the city's electricity consumption.
Both candidates are straining to one-up each other when it comes to public transport. Brisbane isn't large enough to have any direct control over railways but the next few years appear certain to see a very large number of new natural-gas powered buses on the city's roads and an expansion of the CityCat ferry fleet. Mr Incumbent is also touting a spending spree on bicycle paths and facilities.
I offer these examples as evidence of a major and accelerating shift in the public awareness of and concern for sustainability. I've written in the past about my belief that changing values is what brings about changes in behaviour, and I'm starting to become hopeful that values are indeed shifting in the right direction. Heck, I've even listened to speeches from federal parliament this week exhorting the nation to embrace the aboriginal peoples' attitude towards "the land", seeing oneself as literally a part of the environment and being always mindful of the need to care for it.
The question is whether this "trend" will continue. Are we really witnessing the early stages of the transformation of our wasteful, destructive, economically and ecologically irrational society into a responsible, efficient, ecologically-integrated civilisation with advanced culture and traditional wisdom as well as high technology? Well I hope so... because that's what it's probably going to take to avoid catastrophe.
So here's a litmus test for us to monitor our progress as a nation. The Australian Bureau of Agricultural and Resource Economics (ABARE) published a report in December 2007 which predicts that, on the basis of the policies and trends in effect at that time, Australia's energy use will grow by 1.6% per year through to 2030 (that's up about 44% compared to today) with around 92% of that energy being sourced from fossil fuels. Let me suggest that if these projections match our future reality, then we're in very big trouble. But...
If society is in fact changing, embracing values of sustainability, we will necessarily see our energy use grow by a smaller amount than predicted and possibly even declining by 2030. We must also see an major decrease in the proportion of our energy derived from fossil fuels. I'll be keep an eye out for future releases like this one from ABARE to see where we're headed.
In the meantime, we all need to support those politicians who are promoting reduced energy consumption, increased efficiency and a transition to renewable energy sources.
Thursday 7 February 2008
Wet wet wet
I bought a rain gauge a couple of months ago. Managed to resist the impulse to start making daily records. Well, up until a week ago, anyway.
The way our gutters are set up, we can capture the rainfall from about 160 square metres of roof. That means for every millimetre of rain in the gauge about 160L flows into the tanks.
Over the past five days we've had 90mm of rain. That's almost fifteen thousand litres!
Beyond just my own backyard, the whole region is breathing a little easier with significant flows into our water storage dams. From a low of around 17% late last year, storage has almost doubled to around one third of capacity.
The way our gutters are set up, we can capture the rainfall from about 160 square metres of roof. That means for every millimetre of rain in the gauge about 160L flows into the tanks.
Over the past five days we've had 90mm of rain. That's almost fifteen thousand litres!
Beyond just my own backyard, the whole region is breathing a little easier with significant flows into our water storage dams. From a low of around 17% late last year, storage has almost doubled to around one third of capacity.
Saturday 26 January 2008
Stats Update
Average daily consumption for the past 29 days: 7.56kWh of electricity, 160L of town water.
Rainwater in storage: approx 6.4kL.
Per-day stats are one way to think about consumption of resources, but it's a bit of a mental leap to associate those numbers with our actual behaviour. I've started another column on my spreadsheet which puts the electricity use into a different perspective, converting it to an average continuous load.
Our 7.56kWh/day figure is equivalent to using 315W continuously - like having five of the old 60W incandescent light bulbs (or the common halogen downlights) burning day and night.
Rainwater in storage: approx 6.4kL.
Per-day stats are one way to think about consumption of resources, but it's a bit of a mental leap to associate those numbers with our actual behaviour. I've started another column on my spreadsheet which puts the electricity use into a different perspective, converting it to an average continuous load.
Our 7.56kWh/day figure is equivalent to using 315W continuously - like having five of the old 60W incandescent light bulbs (or the common halogen downlights) burning day and night.
Tuesday 22 January 2008
Sustainable Cooking
I've been pondering the issue of energy for cooking - the various energy sources and the technology for using them in the kitchen. Got a few comments and a couple of conclusions to share.
First, burning gas. If we're talking about the fossil fuel kind of gas, I'm opposed to it on the basis that it's a non-renewable, polluting source of energy. Pragmatically speaking it may be an essential part of our transition to sustainability but in the long-term the use of "natural" gas in the kitchen has to stop. I should also mention that in absolute energy terms it's rather inefficient: lots of energy used to extract and transport it, then lots of heat wasted into the air without performing any useful work.
Second, burning wood (or other biomass). In some cases wood is probably the best choice, but I suspect that'll be a minority. Wood is renewable, of course. It's also somewhat polluting especially in areas with dense populations. It's inefficient in terms of being able to direct the heat energy into the cooking but in cold climates that becomes a benefit rather than a problem. Not a good choice for my home though.
Next, solar. Do a web search for "solar oven" and you'll find lots of innovation around the basic theme of using the sun's heat to cook food in an insulated vessel. Absolutely top marks for being clean and sustainable. Not so great for cloudy weather, though, and hard to control in terms of temperature and therefore cooking time. I could imagine this technology becoming more common in the future if other energy systems are struggling to deliver the needs of society... but probably not my own family eating sun-cooked roast veges this coming winter.
Finally, heat from electricity - it's a broad topic. You have to look at both how the electricity is produced and how it is used. The production part of the discussion is well-trodden ground... everybody knows coal is dirty and non-renewable while wind/solar/wave etc offer far cleaner and sustainable sources. No, the really interesting bit is in how the electricity is used.
Most of us have heard that using our microwave oven is a more energy-efficient cooking option than using the standard electric oven or hotplate. That makes sense at first glance. It's not as cut and dried as it sounds, though: consider the case of my own microwave oven.
It's rated at 900W cooking power, which means in theory that it can generate lots of heat directly inside the food instead of heating the materials and air surrounding the food. But if it's putting 900W into the food, why is it drawing 1400W from my AC socket? 500W of power - more than third of the total draw - is being wasted by the machine, lost as heat into my kitchen without touching the food. That's not really very impressive. I've no idea whether other microwave ovens on the market perform any better.
What I do know is that induction cooking is often touted as the safer, more efficient alternative to traditional electric hotplates or gas burners. The technology is vaguely similar to microwave cooking, but instead of using radio waves to transmit energy into the food it uses magnetic fields to transmit energy into the metallic cookware. Proponents like to point out the 85-90% efficiency of converting electrical energy into useful heat (ie heat in the cookware, in contact with the food). Sure beats the 65% that my microwave is capable of.
But I reckon there's an even better electrical cooking technology that's being overlooked. It's cheap, and simple, and already well established in the marketplace. It's your regular old electric frypan. An electric pan has an embedded element which converts 100% of the energy it consumes into heat in the cookware. A portion of that energy is lost as heat radiates away from the pan, but the same could be said of induction cooking technology.
With some simple design improvements - mostly focusing on insulation - highly efficient cooking vessels with embedded electrical heating elements could be the eco-friendly kitchen technology of choice in the future, powered of course using electricity from clean, renewable sources.
First, burning gas. If we're talking about the fossil fuel kind of gas, I'm opposed to it on the basis that it's a non-renewable, polluting source of energy. Pragmatically speaking it may be an essential part of our transition to sustainability but in the long-term the use of "natural" gas in the kitchen has to stop. I should also mention that in absolute energy terms it's rather inefficient: lots of energy used to extract and transport it, then lots of heat wasted into the air without performing any useful work.
Second, burning wood (or other biomass). In some cases wood is probably the best choice, but I suspect that'll be a minority. Wood is renewable, of course. It's also somewhat polluting especially in areas with dense populations. It's inefficient in terms of being able to direct the heat energy into the cooking but in cold climates that becomes a benefit rather than a problem. Not a good choice for my home though.
Next, solar. Do a web search for "solar oven" and you'll find lots of innovation around the basic theme of using the sun's heat to cook food in an insulated vessel. Absolutely top marks for being clean and sustainable. Not so great for cloudy weather, though, and hard to control in terms of temperature and therefore cooking time. I could imagine this technology becoming more common in the future if other energy systems are struggling to deliver the needs of society... but probably not my own family eating sun-cooked roast veges this coming winter.
Finally, heat from electricity - it's a broad topic. You have to look at both how the electricity is produced and how it is used. The production part of the discussion is well-trodden ground... everybody knows coal is dirty and non-renewable while wind/solar/wave etc offer far cleaner and sustainable sources. No, the really interesting bit is in how the electricity is used.
Most of us have heard that using our microwave oven is a more energy-efficient cooking option than using the standard electric oven or hotplate. That makes sense at first glance. It's not as cut and dried as it sounds, though: consider the case of my own microwave oven.
It's rated at 900W cooking power, which means in theory that it can generate lots of heat directly inside the food instead of heating the materials and air surrounding the food. But if it's putting 900W into the food, why is it drawing 1400W from my AC socket? 500W of power - more than third of the total draw - is being wasted by the machine, lost as heat into my kitchen without touching the food. That's not really very impressive. I've no idea whether other microwave ovens on the market perform any better.
What I do know is that induction cooking is often touted as the safer, more efficient alternative to traditional electric hotplates or gas burners. The technology is vaguely similar to microwave cooking, but instead of using radio waves to transmit energy into the food it uses magnetic fields to transmit energy into the metallic cookware. Proponents like to point out the 85-90% efficiency of converting electrical energy into useful heat (ie heat in the cookware, in contact with the food). Sure beats the 65% that my microwave is capable of.
But I reckon there's an even better electrical cooking technology that's being overlooked. It's cheap, and simple, and already well established in the marketplace. It's your regular old electric frypan. An electric pan has an embedded element which converts 100% of the energy it consumes into heat in the cookware. A portion of that energy is lost as heat radiates away from the pan, but the same could be said of induction cooking technology.
With some simple design improvements - mostly focusing on insulation - highly efficient cooking vessels with embedded electrical heating elements could be the eco-friendly kitchen technology of choice in the future, powered of course using electricity from clean, renewable sources.
Wednesday 16 January 2008
High Tech, Low Power and Less Nasty
I have deliberately kept my work and my blog separate. The high tech company I work for has a very strict policy about the way employees represent it in public and it's a line I never want to cross.
Suffice for me to say, my employer has just released a new model of ultra-portable no-compromise laptop computer. It has a full-size screen and keyboard, runs the full version of our latest operating system, uses a fully modern Intel processor... and according to the published specs has an average power consumption of just 8W. Yes I have a tradition of liking this company's products but that little stat particularly impressed me.
It's also nice to see attention given to things like the materials choices (making use of aluminium for its recycling value, eliminating PVCs and BFRs etc) and packaging (smaller packaging increases transport efficiency, materials also selected for recycling).
And the best thing is that it's not just my employer who's doing this - lots of other companies are making actual improvements in their environmental impact. I wonder how far they can go with it by 2050.
Suffice for me to say, my employer has just released a new model of ultra-portable no-compromise laptop computer. It has a full-size screen and keyboard, runs the full version of our latest operating system, uses a fully modern Intel processor... and according to the published specs has an average power consumption of just 8W. Yes I have a tradition of liking this company's products but that little stat particularly impressed me.
It's also nice to see attention given to things like the materials choices (making use of aluminium for its recycling value, eliminating PVCs and BFRs etc) and packaging (smaller packaging increases transport efficiency, materials also selected for recycling).
And the best thing is that it's not just my employer who's doing this - lots of other companies are making actual improvements in their environmental impact. I wonder how far they can go with it by 2050.
Tuesday 8 January 2008
Stats Update
Our mains water consumption for the past 11 days has averaged out to...
187L per day!
That's the total for the five of us, not per person. This is in line with the drop I saw in the last readings period after the tanks were connected to the laundry and toilet. Looks like sub-200 territory is here to stay, at least while there's water in the tanks.
With that qualification in mind, I'm going to start reporting our tank reserves along with these stats. With a specified minimum diameter of 2.2m and a current water height of 110cm in two tanks, we have approx 8.3kL in storage.
Looking at electricity, our hot water system narrowly avoided needing a boost late last week. I had a shower one evening in water that was merely "warm" but with a pause in the rain the next morning the temperature quickly went back up into "ouch" territory. Tariff 33 consumption remains at 0kWh.
Our general consumption is definitely up a bit from the previous trend though. The water pump would be contributing to that. We're using fans to keep ourselves cooler in the warm weather. And maybe we've slacked off a bit with turning things of and generally being frugal. For the past 11 days Tariff 11 usage has averaged 7.4kWh per day.
Just for comparison, here's a graph of our average daily usage per quarter (as per the electricity bill) for the past two years or so. The final column represents the current usage. Would love to get that blue bar down significantly but I'm not sure how I can do that without tossing out the fridge and not cooking food any more.
187L per day!
That's the total for the five of us, not per person. This is in line with the drop I saw in the last readings period after the tanks were connected to the laundry and toilet. Looks like sub-200 territory is here to stay, at least while there's water in the tanks.
With that qualification in mind, I'm going to start reporting our tank reserves along with these stats. With a specified minimum diameter of 2.2m and a current water height of 110cm in two tanks, we have approx 8.3kL in storage.
Looking at electricity, our hot water system narrowly avoided needing a boost late last week. I had a shower one evening in water that was merely "warm" but with a pause in the rain the next morning the temperature quickly went back up into "ouch" territory. Tariff 33 consumption remains at 0kWh.
Our general consumption is definitely up a bit from the previous trend though. The water pump would be contributing to that. We're using fans to keep ourselves cooler in the warm weather. And maybe we've slacked off a bit with turning things of and generally being frugal. For the past 11 days Tariff 11 usage has averaged 7.4kWh per day.
Just for comparison, here's a graph of our average daily usage per quarter (as per the electricity bill) for the past two years or so. The final column represents the current usage. Would love to get that blue bar down significantly but I'm not sure how I can do that without tossing out the fridge and not cooking food any more.
Pipes and Pumps, part 3
I've recently stumbled across the controversial figure of Amory Lovins, a high-profile American advocate of radical energy efficiency improvents through integrative design, improved technology and really obvious (once they're pointed out to you) common-sense actions. In March 2007 Lovins gave a series of five evening lectures at Stanford University and these are available for free download as podcasts through iTunes. I found these less than a week after my pump had been installed... and boy did I wish afterwards that those two events had occurred in the opposite order.
In the Tuesday night lecture on improving energy efficiency in industry, Lovins focused fairly heavily on pipes and pumps. Apparently a very large percentage of the electrical energy used by industry is consumed in the motors of pumps. The point is made that due to the compounding energy losses between electrical generation (usually in a coal-fired power station) and consumption in the motor, even a relatively small improvement in end-use efficiency will be multiplied back through the chain to deliver a far more significant drop in generating capacity requirements and associated pollution emissions etc.
In the pursuit of those end-use efficiency improvements, Lovins laid down a number of basic principles for designing energy-efficient pumping systems. I encourage you to watch the lectures for yourself, but my quick summary would have to include:
- If pipework looks neat, it's probably inefficient
- Short, fat, straight pipes are far more efficient than long, thin pipes with corners in them
- Engineers tend to optimise pipes and pumps separately focusing on up-front cost, when an overall cost reduction can be achieved by optimising them as a system for efficiency
- By optimising the efficiency of the system you can specify a much smaller pump which costs far less to buy, run and maintain
- It's usually best to design the pipework *first* and then lay out the equipment around them
That first point especially hit home. Have a look at the pictures in the previous post or two - I actually insisted that the installer do a "proper" job and fit two additional 90-degree bends in the pipe that takes water to the toilet instead of allowing it to curve smoothly (but untidily). I'm quite sure that if I'd watched this lecture beforehand I'd have spent some time carefully designing and specifying the pipes and pump which are going to be a fixture of our home for some years to come.
Oh well. On the bright side, check out the water use stats I'm about to publish in a separate post.
In the Tuesday night lecture on improving energy efficiency in industry, Lovins focused fairly heavily on pipes and pumps. Apparently a very large percentage of the electrical energy used by industry is consumed in the motors of pumps. The point is made that due to the compounding energy losses between electrical generation (usually in a coal-fired power station) and consumption in the motor, even a relatively small improvement in end-use efficiency will be multiplied back through the chain to deliver a far more significant drop in generating capacity requirements and associated pollution emissions etc.
In the pursuit of those end-use efficiency improvements, Lovins laid down a number of basic principles for designing energy-efficient pumping systems. I encourage you to watch the lectures for yourself, but my quick summary would have to include:
- If pipework looks neat, it's probably inefficient
- Short, fat, straight pipes are far more efficient than long, thin pipes with corners in them
- Engineers tend to optimise pipes and pumps separately focusing on up-front cost, when an overall cost reduction can be achieved by optimising them as a system for efficiency
- By optimising the efficiency of the system you can specify a much smaller pump which costs far less to buy, run and maintain
- It's usually best to design the pipework *first* and then lay out the equipment around them
That first point especially hit home. Have a look at the pictures in the previous post or two - I actually insisted that the installer do a "proper" job and fit two additional 90-degree bends in the pipe that takes water to the toilet instead of allowing it to curve smoothly (but untidily). I'm quite sure that if I'd watched this lecture beforehand I'd have spent some time carefully designing and specifying the pipes and pump which are going to be a fixture of our home for some years to come.
Oh well. On the bright side, check out the water use stats I'm about to publish in a separate post.
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