September 19, 2017 Editor The Wall Street Journal Re: Erin Ailworth, Wind Power Wins Converts in Rural U.S., Sept. 6, 2017
Dear Editor: In her paean to wind power (WSJ, 9/6/17) Erin Ailworth shows that she has never ridden a wind-powered subway or elevator which might have to wait for many hours, or even days for wind power to kick in. She would surely have said something about the port-a-potties. Power from wind varies dramatically with wind speed, as anybody can tell by merely looking at the power curves from any turbine manufacturer on the planet. If the wind speed increases from 10 mph to 20 mph, the power increases by a cool factor of eight. If the wind speed drops from 20 mph to 10 mph, the power it produces drops by 87.5%. Such variations are at odds with the necessity of keeping the grid voltage constant within a few percent, and the frequency constant within 0.03%. In the electricity business, stability is the key ingredient. Nuclear, coal, and natural-gas combined-cycle plants provide baseline voltage. Hydropower kicks in when afternoon demand increases. Wind machines disrupt grid voltage and frequency, and the grid must be stabilized by (usually) natural gas peaking generators running nowhere near their peak efficiency. These are some of the are large costs that are not figured into the LCOE numbers generated in Lazard’s computers and regurgitated by Ms. Ailworth. In the spirit of sobering up the troops, let me present two utterly uncontroversial facts about wind power. 1. By design, the year-round average power from wind turbines is about 35% of the nameplate power. 2. Year-round average power of industrial wind “farms” in good wind sites is a pathetic 5 thousand watts per acre (12.5 kW/ha), regardless of the size of the turbines. For reference, New York City’s average demand is about 10 billion watts. Go figure.
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