Each one of those “Windmills” costs a couple of million dollars. In terms of energy produced they can NEVER recover that cost alone.Maintenance, insurance, market, land aquisition etc, . Basically that energy cannot be stored and must be used somewhere as it is produced. At the present level of the technology it is nothing but a scam.When you see those windmills sitting idle you are watching a multi-million dollar factory effectively shuttered, producing no product. Who can afford to do that? Smile taxpayer. IOW to see who benefits...follow the money.
We know a couple people who live off the grid; they use wind and solar to supplement their propane powered generator to charge the storage batteries that powers their inverter. Propane costs approximately 3 times as much per BTU as natural gas. When they had their system designed they made the assumption that the generator would be supplementing the wind and solar power. It doesn’t work that way for them except for about two months in the middle of the summer.
It was two miles to the nearest utility pole and they could have had those lines strung for less than what their off the grid system cost. But the contractor who set up their system convinced them it would be cheaper in the long run. Within a few months they realized that they had made a mistake. Even in that limited type of system where it almost looks like it would work out... you really have to look at the numbers thoroughly and take system maintenance and ongoing expenses into account. Our friends were blinded by their desire to be energy independent