I used to live in a listed thatched property in an exposed location which is heated by electric storage heaters. Looking up its Energy Performance Certificate online, I see a wind turbine is recommended at a cost of £15,000 to £25,000 which would give a “typical yearly saving” of £725. Of course solar panels could not be fixed to the roof.

There is an interesting vertical axis in development that is just a column. As you know tall metal chimneys vibrate due to vortex shedding so have spiral ribs running up them that somehow alleviate this. However by encouraging the vibration, making it resonate instead of damping it the movement can be harnessed by a generator. The idea is to have lots of poles in a field looking like a fence and not interfering with crop growing or grazing. This is probably the only sort the National Parks parasites would let me have.