If you live on a windy small island or in a desert miles from grid power, it's a good idea to set up your own renewable energy plant. For people living in towns, it's generally not feasible. It's worth considering solar preheat for your hot water, but solar electric panels are hardly worth the investment apart from their questionable greenness. (Governments like them as they need large industrial setups to make; many of the manufacturers are owned by oil companies).
Luckily there's an easy answer in the UK, you can simply buy renewable electricity through the grid from someone like www.good-energy.co.uk . You pay more for the power than running off nuke-juice, but you don't need the investment in hardware or the aggro of arguing with your local council about planning permission for a wind gen mast. I think it's a great idea, and it gets me out of situations when some self righteous ultra green turns up at a workshop and hassles me about recreational welding.