But as protesters fought (so far successfully) the plans for four turbines at Rushey Mead, it has emerged that the reason these things are springing up everywhere is the huge subsidies they attract from the government.
We are told on the one hand the Green Park turbine powers 1,000 homes.
On the other we are told it is one of the least efficient in the country and was built to earn a big subsidy.
If they are so good surely we should have hundreds of them and can stop worrying about burning fuel.
It seems the truth is no one actually knows. And if they do, they seem to have a political point to make which contaminates their view.
Offering these huge subsidies serves simply to make a murky issue even murkier.