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".
Showing posts with label biofuels. Show all posts
Showing posts with label biofuels. Show all posts
Saturday, 31 May 2008
Tuesday, 13 November 2007
Hope for Hydrogen as a Fuel?
Ages ago I posted something about hydrogen, with the basic point being made that hydrogen is not an energy source but an energy carrier and that the fundamental problem with the idea of using hydrogen to power cars etc is that you have to put more energy into making it than you can get out of burning it.
Today though, there is some positive news. Researchers have been able to harness natural microbial action (ie bacteria which munch on organic matter and fart hydrogen instead of methane) and give the process a major efficiency boost with the addition of a small amount of electricity. The result was that the hydrogen released carried between two and six times as much energy as the electricity they had to put in to the system. (The rest of the energy was originally in the organic matter, captured from the Sun.)
At first glance this is potentially a great result, especially compared with biofuels as we know them today which apparently consume more fuel in their production than they provide as the end product. Microbes could munch on all kinds of organic waste and release energy-carrying hydrogen for us to utilise. The process has a much higher efficiency, potentially transforming what was originally solar energy into something we can use in cars.
Next steps: make the process a lot faster. At the moment it's too slow to be useful on any practical scale. But at least it's some positive news.
Today though, there is some positive news. Researchers have been able to harness natural microbial action (ie bacteria which munch on organic matter and fart hydrogen instead of methane) and give the process a major efficiency boost with the addition of a small amount of electricity. The result was that the hydrogen released carried between two and six times as much energy as the electricity they had to put in to the system. (The rest of the energy was originally in the organic matter, captured from the Sun.)
At first glance this is potentially a great result, especially compared with biofuels as we know them today which apparently consume more fuel in their production than they provide as the end product. Microbes could munch on all kinds of organic waste and release energy-carrying hydrogen for us to utilise. The process has a much higher efficiency, potentially transforming what was originally solar energy into something we can use in cars.
Next steps: make the process a lot faster. At the moment it's too slow to be useful on any practical scale. But at least it's some positive news.
Sunday, 28 October 2007
Fuelish Fantasies
One of my favourite bloggers, Greenpa, is a professional scientist who has lived a low-impact lifestyle for 30-odd years. His latest post is a stunner, making a convincing argument about why the dreams of the biofuels industry are more like naive fantasies. Please take a few minutes and have a read.
Then get back to reducing your energy dependence while you still have a chance.
Then get back to reducing your energy dependence while you still have a chance.
Tuesday, 5 June 2007
Understanding Energy - Part 2 of 2
Yesterday's bottom line was this: all the Earth's energy comes from the Sun, it provides life with the ability to grow and to modify the materials of the Earth, and the majority of it eventually heads back out into space as waste heat.
The ancient civilisations of places like Egypt and South America seemed to understand this much better than we do today. Modern man knows clever words like "photosynthesis" but has lost the deep understanding that the Sun is ultimately what puts leaves on the trees and life in our bones.
My best guess at why this is comes down to the discovery of fire, and of "non-living" things which could be burned. Of course I'm referring to coal, oil and natural gas.
Fire is a chemical reaction in which energy that was previously holding atoms together to form molecules is released as heat. Because there's a high concentration of heat energy in one place it's possible for us to channel some of it into causing desirable changes (such as pushing a piston in an engine, melting metal in a furnace or cooking food on a BBQ) before it dissipates and becomes "lost".
For many thousands of years the primary source of chemical energy which humans could harness by setting it alight was wood. Trees spend years soaking up solar energy and converting it to chemical energy that holds together the atoms which form the molecules that comprise its living tissues. At this level the connection between the Sun and the energy available to us in a wood fire is still somewhat intuitive. It's fairly obvious that the trees have to grow before they can be burned.
But coal, oil and gas don't have that same obvious relationship to the Sun. Instead of waiting for a tree to grow you can just dig them up and burn them. And what's more, the amount of chemical energy they contain is far greater than in their equivalent weight of wood. The industrial revolution was unleashed upon the world when people started to figure out more sophisticated ways of using that stored chemical energy to cause changes in materials and motion. That revolution never stopped - we are still living it at full throttle today.
There's just one little problem. Do you remember the two rules of the energy game from yesterday's post?
1. Energy cannot be created or destroyed.
2. Whenever energy is used, some of it gets "lost" and can't be used again.
All that energy in oil didn't just magically appear. Scientists are pretty darn sure that coal and oil and natural gas were formed from the accumulation, over hundreds of millions of years, of solar energy converted by plants into chemical energy and then trapped underground in landslides, floods or similar events. That's why they're called "fossil fuels".
It's like the Earth has an internal rechargeable battery. It's capable of storing an unimaginable amount of energy, and it's in a form which is wonderfully convenient for us to use. It took hundreds of millions of years to charge it up, but in the span of a couple of hundred years we've managed to run the battery down to about 50% charge remaining and at this rate it'll be fully exhausted by about the end of this century.
Let me say that again. We've consumed hundreds of millions of years worth of stored solar energy in just a few centuries, and now we're starting to run out.
The discussion about how much fossil fuel energy remains to be dug up and burned is a complicated one and is made worse by the unfortunate side-effect that we call climate change. I'm going to side-step the whole question of exactly when fossil fuels will cease to be able to meet our energy needs for transport and electricity production - but it will inevitably happen. In many parts of the world energy supply is already struggling to keep pace with demand.
But what else is there?
Governments and corporations the world over are turning to "biofuels" to try and compensate for falling oil production. But the math just doesn't add up: the rate of conversion from sunlight to chemical energy is far too slow to allow it to meet the current demand for oil. Besides which, studies seem to show that in many cases you use about as much oil producing the crop (for powering farm machinery etc) as you get back from the crop in the final product, making the whole enterprise a waste of oil and food at this point in time. Technological advances may make the process more efficient in the future, though, so continued research is worthwhile.
Solar photovoltaic technology - which uses tricks of physics to convert sunlight falling on a substance directly into electricity - has a similar problem. The technology keeps getting better but there's a limited amount of the raw materials needed to make the panels and producing them consumes significant amounts of energy. We probably can't produce enough of them and they don't give back enough energy to make them a silver bullet solution to our electricity dependency, but again more research is needed.
Heating water with solar collectors is a no-brainer and I applaud moves from the Queensland government to phase out the old electric-powered type. Wish it would happen sooner.
Using wind to generate electricty (converting kinetic energy from the moving air into electrical energy in the turbine) is also a pretty smart idea. The wind moves because the Sun heats the air, so tapping into that energy flow is sustainable in the true sense of the word. There are some concerns about the amount of energy used in construction vs the amount of energy the turbine can harness over its lifetime, but those issues can probably be solved through engineering.
Hydro-electric systems are also driven by the Sun. It's the Sun which heats the water and causes it to evaporate. It's the Sun which drives the wind that carries the vapour up over the higher land, imbuing it with gravitational potential energy. As the water flows down again towards sea level we can extract some of that energy to turn a turbine and convert it to electricity.
Wave and/or tidal energy. Waves are caused by the wind, which in turn is powered by the Sun, and there's a colossal amount of kinetic energy in the movement of the water. Harnessing that's a great idea. The tides are due to the gravitational pull of the Moon on the water. Taking energy from that system will actually cause the Moon to orbit more slowly and crash into Earth... but that's going to happen eventually anyway and it's unlikely we'll make any significant impact. (No pun intended.)
Geothermal (hot rocks). Not, strictly speaking, a renewable resource but definitely a clean one. Worth looking at where the geology is appropriate.
Nuclear. Ah, had to get to this eventually. Ultimately, nuclear energy is a form of stored energy that was locked into atoms by long-dead stars. It's completely natural but - like molten lava or the Sydney funnelweb spider - not something you want to get too close to. It's interesting to note that some of the geothermal heat which people want to harness was actually released during the radioactive decay of unstable nuclei. There is a lot of nuclear energy available to us here on Earth but like fossil fuels there are undesirable side-effects and it's not a renewable resource.
And that, pretty much, is it. We need to stop using fossil fuels now due to global warming but we will simply run out of oil soon anyway. Nuclear technology will continue to play a role in the global energy mix for a very long time, and it's possible that new developments could greatly reduce the risks associated with radioactive waste and other concerns. The rest of them are all important because none of them can supply so much energy in such a convenient form as fossil fuels have done for the past couple of centuries.
There's a lot of work needed to secure energy supplies and maintain a habitable planet, even just for the rest of this century. I've started doing my bit and you can too.
Thanks so much for reading this far. Questions, comments, corrections all are welcome.
The ancient civilisations of places like Egypt and South America seemed to understand this much better than we do today. Modern man knows clever words like "photosynthesis" but has lost the deep understanding that the Sun is ultimately what puts leaves on the trees and life in our bones.
My best guess at why this is comes down to the discovery of fire, and of "non-living" things which could be burned. Of course I'm referring to coal, oil and natural gas.
Fire is a chemical reaction in which energy that was previously holding atoms together to form molecules is released as heat. Because there's a high concentration of heat energy in one place it's possible for us to channel some of it into causing desirable changes (such as pushing a piston in an engine, melting metal in a furnace or cooking food on a BBQ) before it dissipates and becomes "lost".
For many thousands of years the primary source of chemical energy which humans could harness by setting it alight was wood. Trees spend years soaking up solar energy and converting it to chemical energy that holds together the atoms which form the molecules that comprise its living tissues. At this level the connection between the Sun and the energy available to us in a wood fire is still somewhat intuitive. It's fairly obvious that the trees have to grow before they can be burned.
But coal, oil and gas don't have that same obvious relationship to the Sun. Instead of waiting for a tree to grow you can just dig them up and burn them. And what's more, the amount of chemical energy they contain is far greater than in their equivalent weight of wood. The industrial revolution was unleashed upon the world when people started to figure out more sophisticated ways of using that stored chemical energy to cause changes in materials and motion. That revolution never stopped - we are still living it at full throttle today.
There's just one little problem. Do you remember the two rules of the energy game from yesterday's post?
1. Energy cannot be created or destroyed.
2. Whenever energy is used, some of it gets "lost" and can't be used again.
All that energy in oil didn't just magically appear. Scientists are pretty darn sure that coal and oil and natural gas were formed from the accumulation, over hundreds of millions of years, of solar energy converted by plants into chemical energy and then trapped underground in landslides, floods or similar events. That's why they're called "fossil fuels".
It's like the Earth has an internal rechargeable battery. It's capable of storing an unimaginable amount of energy, and it's in a form which is wonderfully convenient for us to use. It took hundreds of millions of years to charge it up, but in the span of a couple of hundred years we've managed to run the battery down to about 50% charge remaining and at this rate it'll be fully exhausted by about the end of this century.
Let me say that again. We've consumed hundreds of millions of years worth of stored solar energy in just a few centuries, and now we're starting to run out.
The discussion about how much fossil fuel energy remains to be dug up and burned is a complicated one and is made worse by the unfortunate side-effect that we call climate change. I'm going to side-step the whole question of exactly when fossil fuels will cease to be able to meet our energy needs for transport and electricity production - but it will inevitably happen. In many parts of the world energy supply is already struggling to keep pace with demand.
But what else is there?
Governments and corporations the world over are turning to "biofuels" to try and compensate for falling oil production. But the math just doesn't add up: the rate of conversion from sunlight to chemical energy is far too slow to allow it to meet the current demand for oil. Besides which, studies seem to show that in many cases you use about as much oil producing the crop (for powering farm machinery etc) as you get back from the crop in the final product, making the whole enterprise a waste of oil and food at this point in time. Technological advances may make the process more efficient in the future, though, so continued research is worthwhile.
Solar photovoltaic technology - which uses tricks of physics to convert sunlight falling on a substance directly into electricity - has a similar problem. The technology keeps getting better but there's a limited amount of the raw materials needed to make the panels and producing them consumes significant amounts of energy. We probably can't produce enough of them and they don't give back enough energy to make them a silver bullet solution to our electricity dependency, but again more research is needed.
Heating water with solar collectors is a no-brainer and I applaud moves from the Queensland government to phase out the old electric-powered type. Wish it would happen sooner.
Using wind to generate electricty (converting kinetic energy from the moving air into electrical energy in the turbine) is also a pretty smart idea. The wind moves because the Sun heats the air, so tapping into that energy flow is sustainable in the true sense of the word. There are some concerns about the amount of energy used in construction vs the amount of energy the turbine can harness over its lifetime, but those issues can probably be solved through engineering.
Hydro-electric systems are also driven by the Sun. It's the Sun which heats the water and causes it to evaporate. It's the Sun which drives the wind that carries the vapour up over the higher land, imbuing it with gravitational potential energy. As the water flows down again towards sea level we can extract some of that energy to turn a turbine and convert it to electricity.
Wave and/or tidal energy. Waves are caused by the wind, which in turn is powered by the Sun, and there's a colossal amount of kinetic energy in the movement of the water. Harnessing that's a great idea. The tides are due to the gravitational pull of the Moon on the water. Taking energy from that system will actually cause the Moon to orbit more slowly and crash into Earth... but that's going to happen eventually anyway and it's unlikely we'll make any significant impact. (No pun intended.)
Geothermal (hot rocks). Not, strictly speaking, a renewable resource but definitely a clean one. Worth looking at where the geology is appropriate.
Nuclear. Ah, had to get to this eventually. Ultimately, nuclear energy is a form of stored energy that was locked into atoms by long-dead stars. It's completely natural but - like molten lava or the Sydney funnelweb spider - not something you want to get too close to. It's interesting to note that some of the geothermal heat which people want to harness was actually released during the radioactive decay of unstable nuclei. There is a lot of nuclear energy available to us here on Earth but like fossil fuels there are undesirable side-effects and it's not a renewable resource.
And that, pretty much, is it. We need to stop using fossil fuels now due to global warming but we will simply run out of oil soon anyway. Nuclear technology will continue to play a role in the global energy mix for a very long time, and it's possible that new developments could greatly reduce the risks associated with radioactive waste and other concerns. The rest of them are all important because none of them can supply so much energy in such a convenient form as fossil fuels have done for the past couple of centuries.
There's a lot of work needed to secure energy supplies and maintain a habitable planet, even just for the rest of this century. I've started doing my bit and you can too.
Thanks so much for reading this far. Questions, comments, corrections all are welcome.
Saturday, 2 June 2007
Notes from Caboolture Sustainable Living Fair
Well that was interesting. CREEC wasn't hard to find, and I was pleased to see it's quite close to the Burpengary train station. I might find myself heading that way for a bike/train outing every now and then to participate in some of their events. It was about 22km from my place by car.
I went along to this fair with a few priorities in mind:
1. Find out more about growing food in the back yard and/or community gardens
2. Ask about distribution schemes for locally-grown produce
3. Try to make contact with people who live nearby and are focused on sustainable living
4. Maybe clarify the Greens' position on alternative nuclear energy technologies (there are some which don't produce waste that lasts for thousands of years and are almost useless for making weapons... but you don't hear about them much)
Amazingly enough, I scored four out of four.
I met some very nice and enthusiastic people from Permaculture Caboolture (not sure whether they're technically a club, society or what) who have heaps of information to share about growing food and who know heaps of other people to link up with to promote food gardening at home or in community gardens or in school programs. I'll be following up on a number of the suggestions I received and will be sure to note them here online.
There's apparently a meeting somewhere in Brisbane this coming week regarding a program which teaches organic gardening and food preparation to primary school children as part of their routine curriculum. Will make an effort to get along and check that out.
Regarding local food distribution, there's an organic farm at Beerwah which sells "subscriptions": each week you give them $60 and they give you a big box of assorted veges. The Permaculture Caboolture people are hoping to start a monthly organic farmers market at CREEC starting on the 14th July. And another bloke is talking about establishing a community garden program at Petrie, which would also link up with the regular markets which are held out that way.
And I did enjoy a chat with a guy on the Australian Greens stand about the theoretical possibility of safe, clean nuclear energy production using technologies which are quite unlike the uranium fuel cycle that everybody associates with the term "nuclear". I was very pleased with the open-minded and sensible reaction - he'd even heard of thorium before I mentioned it.
A few other quick observations to wrap up:
I went along to this fair with a few priorities in mind:
1. Find out more about growing food in the back yard and/or community gardens
2. Ask about distribution schemes for locally-grown produce
3. Try to make contact with people who live nearby and are focused on sustainable living
4. Maybe clarify the Greens' position on alternative nuclear energy technologies (there are some which don't produce waste that lasts for thousands of years and are almost useless for making weapons... but you don't hear about them much)
Amazingly enough, I scored four out of four.
I met some very nice and enthusiastic people from Permaculture Caboolture (not sure whether they're technically a club, society or what) who have heaps of information to share about growing food and who know heaps of other people to link up with to promote food gardening at home or in community gardens or in school programs. I'll be following up on a number of the suggestions I received and will be sure to note them here online.
There's apparently a meeting somewhere in Brisbane this coming week regarding a program which teaches organic gardening and food preparation to primary school children as part of their routine curriculum. Will make an effort to get along and check that out.
Regarding local food distribution, there's an organic farm at Beerwah which sells "subscriptions": each week you give them $60 and they give you a big box of assorted veges. The Permaculture Caboolture people are hoping to start a monthly organic farmers market at CREEC starting on the 14th July. And another bloke is talking about establishing a community garden program at Petrie, which would also link up with the regular markets which are held out that way.
And I did enjoy a chat with a guy on the Australian Greens stand about the theoretical possibility of safe, clean nuclear energy production using technologies which are quite unlike the uranium fuel cycle that everybody associates with the term "nuclear". I was very pleased with the open-minded and sensible reaction - he'd even heard of thorium before I mentioned it.
A few other quick observations to wrap up:
- A lot of paper brochures being given away - how ironic.
- Good representation from Caboolture Shire Council, but with an unsurprising emphasis on economic considerations and "waste management" as opposed to true sustainability.
- I was surprised to see fast food and pre-packaged drinks on sale. (Thumbs up to the organic sausage sizzle though for good taste and the single paper napkin.)
- Local businessman pushing a carbon sink program: $40 for 17 trees, 100 year expected lifespan. It's probably a good thing.
- Greens guy reckons that ethanol being produced for fuel in Qld is derived from the waste material left over from sugar production as opposed to the sugarcane juice itself. I need to do some more research: that might tip the overall energy balance in favour of that particular scheme... but you can bet your Porsche that it's not scalable to the point where it replaces even a small fraction of the state's fuel requirements.
Friday, 11 May 2007
NSW bets the farm on ethanol
Significant news from south of the border: New South Wales is set to become the first state to mandate the use of ethanol in petrol.
About the only positive thing I can come up with in response to this is that increasing demand might spur investment and innovation, which in turn might lead to the development of a biofuels industry that:
About the only positive thing I can come up with in response to this is that increasing demand might spur investment and innovation, which in turn might lead to the development of a biofuels industry that:
- doesn't compete directly with food production
- doesn't encourage deforestation and land degradation
- doesn't increase the already massive stress on our waterways
- doesn't require fossil fuel input for fertilisers and machinery
- has a chance of producing more than a couple of percent of our transport fuel requirements
Saturday, 28 April 2007
No Silver Bullets (re Peak Oil)
My previous post was about the tension between the growing demand for oil and predictions of declining availability, and the relationship of oil consumption to global warming.
I expect that many people reading that post would quickly reassure themselves by thinking about one or more of the following:
- biofuels (especially ethanol for use in existing cars)
- electric, hybrid or hydrogen-powered vehicles
- coal liquefaction (literally converting coal into a fluid form similar to oil)
Here's why none of those make me worry much less, if at all.
1. Biofuels
The basic idea is neat: instead of giving carbon a one-way trip from oil to the atmosphere, lets grow plants to take CO2 out of the air then convert it to fuel which when burned puts the carbon back where it came from. The overall amount of CO2 in the air stays constant and we don't need oil.
But already we've hit a fatal flaw with biofuels: in fact the production of ethanol from, say, corn requires massive inputs of oil in the form of fertilisers, pesticides and fuel for agricultural machinery and transport. It also requires significant electrical input which - especially in Australia - basically means burning coal. So we're still consuming oil and adding CO2 to the atmosphere even before the ethanol gets into our petrol tanks.
Fatal flaw #2 is so obvious I'm stunned we are even bothering to attempt growing fuel. Our cars and trucks and planes and ships consume enormous amounts of fuel. Even if we dedicated all the productive land on the planet to growing fuel crops we would only manage to produce a fraction of the fuel we need to keep everything running at the current pace - let alone meet the exponential demand predicted for the future.
There is some research being done into growing algae in tanks or ponds as an alternative to land-based fuel crops. This may lead to a significant, sustainable biofuel industry and I'd be encouraged by that. But from what I've read it's still not likely to ever be enough to match our current appetite for oil.
2. High tech cars
It's true. We can make cars which don't need to burn oil.
Some people are keen on cars similar to the ones we have today but which burn hydrogen gas (H2) instead. There's no "C" in hydrogen, so when you burn it you just get H2O. Water vapour. But hydrogen gas is highly explosive (can you say "Hindenburg"?) and it's very difficult to handle. Oh yeah, and water vapour is a much more powerful greenhouse gas than is carbon dioxide.
So there's a lot of attention on using hydrogen in fuel cells - basically little modules of hardware that generate electricity through chemical reactions and which you'd either swap in and out of your car like rechargable batteries in a camcorder, or top up with additional hydrogen. Fuel cells are real enough (they're used in the Space Shuttle, for example) but the technology needs a fair bit of development before it's suitable for use in everyday transportation.
Sounds good, huh? Uh-oh, here it comes.
Hydrogen's fatal flaw when it comes to the global warming / peak oil dilemma is that it generally isn't a source of energy but a carrier of energy. Hydrogen can't be mined*, it has to be produced. The simplest way to produce it is to push an electric current into water so that you give the hydrogen atoms the energy they need to escape their bonds to the oxygen atoms. That's how it acquires the energy which we want to use later on when we burn it in an engine.
Fuel cells and electric vehicles get lassoed with the same rope now. All these vehicles depend on large inputs of electrical energy. Hopefully you recall that our electrical consumption is already a major concern because of the CO2 we emit when we generate it. Unless we come up with a revolutionary large-scale way to produce electricity, these cars would simply drive us from the peak oil frying pan into the global warming fire.
3. Coal liquefaction
I only learned about this one recently, but it's old technology. During one of the Great Wars the British were astonished that their attacks on the German sources of oil didn't bring the Nazi machine to a halt. The Germans had prepared by switching to production of liquid hydrocarbons from coal.
The world does have heaps of coal (though calculations for "Peak Coal" are already being debated) and I get the impression that it's relatively simple and efficient to convert it to a liquid. On the positive side, this may help alleviate the shortage of raw material for plastics and fertilizers etc. But of course burning the stuff in cars is just as bad as burning it in power stations. As a greenhouse-friendly replacement for oil, coal is also fatally flawed.
Three bullets: shiny-looking, but definitely not silver.
* I am simplying things a fair bit with regards to hydrogen as an energy carrier but it's generally true that getting usable H2 on a very large scale would require massive energy input and that would predominantly come from coal at this point in time.
I expect that many people reading that post would quickly reassure themselves by thinking about one or more of the following:
- biofuels (especially ethanol for use in existing cars)
- electric, hybrid or hydrogen-powered vehicles
- coal liquefaction (literally converting coal into a fluid form similar to oil)
Here's why none of those make me worry much less, if at all.
1. Biofuels
The basic idea is neat: instead of giving carbon a one-way trip from oil to the atmosphere, lets grow plants to take CO2 out of the air then convert it to fuel which when burned puts the carbon back where it came from. The overall amount of CO2 in the air stays constant and we don't need oil.
But already we've hit a fatal flaw with biofuels: in fact the production of ethanol from, say, corn requires massive inputs of oil in the form of fertilisers, pesticides and fuel for agricultural machinery and transport. It also requires significant electrical input which - especially in Australia - basically means burning coal. So we're still consuming oil and adding CO2 to the atmosphere even before the ethanol gets into our petrol tanks.
Fatal flaw #2 is so obvious I'm stunned we are even bothering to attempt growing fuel. Our cars and trucks and planes and ships consume enormous amounts of fuel. Even if we dedicated all the productive land on the planet to growing fuel crops we would only manage to produce a fraction of the fuel we need to keep everything running at the current pace - let alone meet the exponential demand predicted for the future.
There is some research being done into growing algae in tanks or ponds as an alternative to land-based fuel crops. This may lead to a significant, sustainable biofuel industry and I'd be encouraged by that. But from what I've read it's still not likely to ever be enough to match our current appetite for oil.
2. High tech cars
It's true. We can make cars which don't need to burn oil.
Some people are keen on cars similar to the ones we have today but which burn hydrogen gas (H2) instead. There's no "C" in hydrogen, so when you burn it you just get H2O. Water vapour. But hydrogen gas is highly explosive (can you say "Hindenburg"?) and it's very difficult to handle. Oh yeah, and water vapour is a much more powerful greenhouse gas than is carbon dioxide.
So there's a lot of attention on using hydrogen in fuel cells - basically little modules of hardware that generate electricity through chemical reactions and which you'd either swap in and out of your car like rechargable batteries in a camcorder, or top up with additional hydrogen. Fuel cells are real enough (they're used in the Space Shuttle, for example) but the technology needs a fair bit of development before it's suitable for use in everyday transportation.
Sounds good, huh? Uh-oh, here it comes.
Hydrogen's fatal flaw when it comes to the global warming / peak oil dilemma is that it generally isn't a source of energy but a carrier of energy. Hydrogen can't be mined*, it has to be produced. The simplest way to produce it is to push an electric current into water so that you give the hydrogen atoms the energy they need to escape their bonds to the oxygen atoms. That's how it acquires the energy which we want to use later on when we burn it in an engine.
Fuel cells and electric vehicles get lassoed with the same rope now. All these vehicles depend on large inputs of electrical energy. Hopefully you recall that our electrical consumption is already a major concern because of the CO2 we emit when we generate it. Unless we come up with a revolutionary large-scale way to produce electricity, these cars would simply drive us from the peak oil frying pan into the global warming fire.
3. Coal liquefaction
I only learned about this one recently, but it's old technology. During one of the Great Wars the British were astonished that their attacks on the German sources of oil didn't bring the Nazi machine to a halt. The Germans had prepared by switching to production of liquid hydrocarbons from coal.
The world does have heaps of coal (though calculations for "Peak Coal" are already being debated) and I get the impression that it's relatively simple and efficient to convert it to a liquid. On the positive side, this may help alleviate the shortage of raw material for plastics and fertilizers etc. But of course burning the stuff in cars is just as bad as burning it in power stations. As a greenhouse-friendly replacement for oil, coal is also fatally flawed.
Three bullets: shiny-looking, but definitely not silver.
* I am simplying things a fair bit with regards to hydrogen as an energy carrier but it's generally true that getting usable H2 on a very large scale would require massive energy input and that would predominantly come from coal at this point in time.
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