Light switches

Lighting is a great place to start talking about simple, economical things that everybody can do to reduce energy consumption and hence greenhouse gas emissions and other pollution related to electricity generation.

Literally all it takes is a tiny bit of attention to switch off lights that don't actually need to be on. According to the government lighting presently accounts for about 12% of the average Australian household's greenhouse gas emissions - a large enough chunk to justify trying to cut it back.

Switching off is easy, it's effective, and it actually increases your bank balance without a cent of up-front investment. In the Brady household we've taken this to heart and are making a conscious effort to only use lights when we actually need to - for a large part of most evenings there are only three bulbs switched on in the house.

But you can approach most resource use problems from two directions: you can reduce demand (switch off lights to use less electricity) or you can increase efficiency (find a way to get more light from less electricity). And it so happens that Australia is getting right behind a more efficient lighting technology: the compact fluorescent light bulb.

Standard "incandescent" bulbs make light through brute force. They slam electrons into atoms of tungsten metal, which responds by converting most of the energy into waste heat. But if you throw enough electrons at it the tungsten gets really hot and starts to give off some light in addition to all the heat. No disrespect to Mr Edison, but what he invented is essentially a heater which glows.

"CF" bulbs are basically miniature, folded up versions of the long skinny tubes which most of us have in our kitchens and which congregate in large numbers on the ceilings of offices and public buildings. By using materials which are naturally inclined to emit light (as opposed to using a dull grey metal) they convert a much greater fraction of their energy input into light and only a small amount into waste heat.

CF bulbs use about a fifth of the energy of an incandescent bulb which produces the same amount of light. And that's why in a few years time we Aussies won't be able to buy the old kind any more.

The major drawback is the cost. We have installed 25 CF bulbs here at an average cost of roughly $5 to $8 each. But the manufacturers claim that the combination of reduced electrical bills and much longer lifespan means they'll more than pay for themselves in the end.

If finding the money to replace all your bulbs up front is a challenge, there's still plenty you can do. Start, of course, by switching off lights you don't really need turned on. Consider buying a small number of CF bulbs to install in the sockets that get used most - probably in the lounge, the dining room and the bedroom. Or you could replace your incandescent bulbs one at a time as they burn out.

We've only made the big switch recently, so it's going to take a while before we notice any difference in our electricity bills. I'm considering checking my own meter once a week or so and crunching some numbers. Will keep you "posted".