The key to reducing our energy use, and hence our contribution to climate change and our exposure to energy insecurity, is efficiency.

Efficiency is easy and available now. It doesn't rely on new technologies or multi-billion pound investments, high risks or low politics. It's not sexy either, but it works.

The government's own figures say the UK could quite easily use 30% less energy, with no huge changes.

Interesting, then, that even trains are getting in on the act. The BBC (see link) reports that trains are using their braking power to return electricity to the overhead power lines. The train companies are also working out how to do the same for 'third rail' systems.

This method, equivalent to what hybrid cars do, could save 15% of the train companies' electricity bill. That's like 1 train in 7 running for free.