We have solar panels on our roof that heat our water.
Now they never seemed a great financial investment but they do reduce our gas and electricity use significantly. Maybe such panels should be made much more of a standard fitting on new houses. Sometimes we have so much hot water we can't use it all - I'd love to be able to sell our hot water to our neighbours in some way - it seems silly that we have abundant hot water and they may be using fossil fuels to heat the water for their bath or shower in the house next door! It's not difficult to imagine ways of building new housing where such green technology is shared in some way. Surely the future will have more of such green technology?
So it's a shame that the firm that installed our solar panels has ceased trading - it seems that it's difficult to make money in the UK out of the green future.