How Many Windmills Does It Take to Power the World?

Power densities are a measure of the land required for both energy sources and energy users. The current infrastructure matches the small footprint of energy sources against the large footprint of energy users. With the drive toward renewable energy sources, this relationship is about to be reversed with consequences few people understand.

Though nowadays people sometimes rail against the deployment of wind generators because they mar the view, such deployments are the logical outcome of our desire to move away from fossil fuels. We may be concerned about the greenhouse gasses and toxic pollution emitted by coal-fired power plants, but most people do not worry about such plants ruining their view unless they live very nearby. Neither do they worry about coal mines unless, of course, they live in proximity to them, and only a very small segment of the population does.


But windmills can be put anywhere there is sufficient wind. And, that often conflicts with the aesthetic desires of people who must look at them and deal with the attendant disruption that servicing them causes. It’s not just that coal-fired power plants can be plunked down pretty much wherever we want them. It’s also that watt for watt they are far more compact than their equivalent in wind turbines.

Let’s take a 500-megawatt power plant which by itself can power a city of 300,000. (A megawatt is one million watts.) It will sit astride a fairly large plot of land. A coal-fired plant near me is just under that capacity (495 MW) and sits on about 300 acres. Most of that land, however, is essentially devoted to undeveloped transmission right-of-way filled with ponds, woods and streams. Only a small portion is covered by plant facilities including coal storage. I estimate less than 30 acres.

Scitizen