Wind power. The question was about why wind machines seldom seem to be running, questioning if maintenance might be the problem, all that oil and grease.
The reason is demand, of lack of it. The only way to keep the machines running full time is by installing massive banks of storage batteries so the energy can be used when people want it. The wind seldom blows exactly when the electricity is needed.
Since the cost of the machines and running them is so high, the cost of installing batteries would bankrupt the owners.
Were it not for the laws, economics would dictate and there would be a lot less wind farms. National average electric cost is somewhere around 10 cents per kWh. Wind power cost without batteries is around 15 cents per kWh.
Don't forget about all the environmental issues surrounding batteries!
Should you dig out the whole truth, look at both sides of every story you will usually find that the only thing green is the color of the money.