Friday, June 06, 2008

renewable energy

There isn't any. All the energy in the world comes from the sun. That's not some poetic way of expressing it - it's hard every day science. So it really doesn't make any difference whether we dig up solar energy which is stored in millions of years old fossil fuels or stick a piece of glass and metal out in the desert and collect the suns rays direct. There is still a zero gain in energy over what would have happened anyway.

Now, there are undoubtably different costs involved with different sources of energy (atmospheric pollution being the one we are currently most exercised by) but in the end they are all inefficient (as all systems are) and chuck out low grade unusable energy (heat) as a biproduct. If you look at the development of civilisation you can see how we never think very far ahead as to the consequences of technological progress. Once there were a lot of trees and wood was considered inexhaustable but they did run out in many of the more developed countries or at least run low to the point of irrevocably changing the environment. Then coal was discovered which seemed pretty inexhaustable. But although, air pollution was a very real local problem during the industrial revolution, nobody really thought about polluting the whole atmosphere - it was so big people just thought of it as infinite. Now we worry about the proportion of CO2 in the air but the alternatives that are being trotted out are just falling into the same trap of a century ago of thinking of systems so big they might as well be infinite.

Take an innoculous solar panel. What harm can it possibly be doing? It just sits there and turns suns rays into useful energy. Fine. In the same way that a coal powered steam engine is fine. Both work well in isolation. But let's be realistic about our current and future power requirements. Take a look at the per capita energy use of different countries ( and you see a pattern: the more developed the country the more power per head. Now look where China and India are: down near the bottom and the world average is well down there as well. So forget your energy saving lightbulbs, we are going to need more energy, a lot more energy. Per person. With a world population increasing exponentially. And energy requirements in the most developed countries still increasing. So we don't need a few solar panels. We could cover the Sahara with solar panels and it wouldn't be enough in ten or fifty years. And when you get to that scale you will get environmental effects (some that you just didn't think about: like what happens to the climate when you concentrate all that heat in one place) And don't forget the cost on resources of building them, transporting them, maintaining and replacing them.

Ultimately any effort to use the solar energy which is falling on the Earth anyway is doomed because this energy is already providing the fuel for the natural systems in place: the biosphere, water cycle etc. So we can't cut back (nobody is going to accept that we go back to a more primitive phase of our development) and we can't get enough energy from any Earthbound sources. All we are doing is cannibalising the planet and everything is degrading in the process. We need to forget about being careful and concentrate our dwindling resources on long term fixes which actually add to the energy on the planet (solar panels in orbit would be a good place to start). It's going to be expensive and use precious resources but ultimately it will save far more. I read a website which stated 'straight faced' that it would "only need an area the size of France" covered with solar panels to meet our energy needs. Fine, but put it in space not on precious land down here. That way we continue to get all the solar energy incoming that we would have anyway and our power needs from a separate source.

Take the War as a comparison. Resources were very tight. So the choice is whether to spend money on munitions to fight on the front or to protect shipping convoys in the Atlantic bringing new resources. We can fight against using up our existing resources too fast or we can invest them in bringing in new resources.

I heard a really good comment on Radio 4 that the amount of CO2 we can 'safely' add to the atmosphere before the effect is really horrendous is one trillion tonnes. The question, he said, is not "How much can we cut back?" but "How quickly will we reach the 1Tn mark?" and then "What are we going to do with the next 1Tn tonnes?" It has taken us a couple of hundred years since the industrial revolution to hit the half Tn and will take a few decades for the next half Tn.