Following-on from the story about energy-generation in India, it seems there is a similar thing we could do in the UK… and it was invented in France maybe fifty years ago.
A guy called Jean Pain took a large amount of plain brush wood and chipped it into small fragments. He then placed this into a steel tank (about 6 by 3 metres) where it began to compost.
By placing pipes through the centre of the tank he was able to extract hot water. He also extracted the methane gas generated by the composting process, which he used for cooking and for running his truck.
A single tank of 50 cubic metres provided gas and hot water for 18 months.
Using bacteria to convert the wood into heat and gas in this way generates more energy than you would get simply by burning the material.
Here is a diagram of how it works:
And you can read the wikipedia entry here.
There is also a documentary about Jean Pain here: