Oil is apparently still too cheap for the punters to start seriously conserving energy.

I was talking to a plumber friend the other day who was telling me about all the tricks that are used to prevent the waste water in high-rise buildings causing problems after it's flushed (potential problems include damaging pressure surges). I said why don't they just remove the impediments, put a turbine at the bottom and generate some power out of all those wasted flushes! I was only joking but he said he'd never heard of anyone trying that - so we coined a name for this idea, the "turd-bine"...

Excellent - maybe you should patent the idea (and name).

But I think these sorts of schemes (combined with energy efficient designs) to extract small amounts of available energy that are readily available will become more and more worthwhile.

I expect that in 40 years time every building will have solar panels, better insulation and an array of energy harvesting and energy efficient devices within and supporting it - by and large being self-sufficient in energy.