What if the electricity from a wind farm is generated mainly when there’s no economic use for it? It can’t be stored, so it is simply wasted.
As the California experience documents below, wind generation and grid load have different patterns.
A similar condition prevails in upstate New York, as admitted by General Electric. (See GE’s System Performance Evaluation to the NY State Energy Research and Development Authority.) Likewise in our area. The result is that even though a turbine or wind farm is usually touted for its rated capacity, only about 10% of that represents electricity that is usable.
That’s right. Not the 1.5 MW - 2.0 MW turbine capacity touted by wind brokers and pro-wind media. Not even 20-30% of that amount, which results after factoring in the lack of optimal wind (efficiency factor) prevalent in our area. But only about 10%, or 0.15 MW, will be expected to be usable from a 1.5 MW turbine, because the electricity it generates will be generated mostly at night and other times of least economic use for it, when electricity demand on the grid is lowest.
When you read that a wind farm of 40 turbines, each rated at 1.5 MW, will generate 60 MW of electricity, you should understand how misleading these numbers actually are, when it comes down to electricity that is actually usable. In our area, dividing by ten wil give more realistic estimates.
By using rated capacity as the basis for usuable generation estimates, wind brokers exaggerate by a factor of 10 or more.
Thanks to Moorsyde Wind Farm Action Group, an excellent resource on wind power.