I do worry about the sort of argument that hopes there is some wonder product that will get us back to the good old days where we can squander energy with impunity. It is interesting to see the efficiencies of photovoltaic and compare it with plants and solar hot water, I would love to see the same sort of technological leap, similar to blue leds, where science said it couldn't be done and then one guy sorts it out in 18 month's or so. fantastic! But it is very easy to get washed along with the overall enthusiam for the idea.
The real issue is how we can reduce the heat we produce, or to paraphrase, the energy we consume and that will be a problem however the energy is consumed.
Realistically, our expectation of lifestyle must change markedly, and the lot of our children will be even more abstemious. I travelled over 250 miles today in a car to an electrical show in Coventry and spent an hour in a traffic jam on the way back. My only defence is I went with a friend but such a cavalier attitude to distance really isn't viable for too much longer. If we combine a reduction in usage with some of the truly marvellous ways we have of acknowledging our understanding of the phyical processes around us then we genuinely might build a society that has a future.
That said, as Mr Drury sang, to those of a certain age. 'There ain't half been some clever bastards!'
