The U.S. wind turbine industry had a phenomenal month in April, with all its factors coming together to breeze past coal’s capacity factor.
14 Jul 2017 – Green Tech Media
The Energy Information Administration’s Electric Power Monthly (Tables 6.7.A and 6.7.B) put wind at 44.8 percent, slightly above coal’s 43.4 percent — and just below the 45.7 percent of the nation’s combined-cycle natural-gas plants.
A closer look at these contributing factors will help give better context for this achievement, so we’ll review each in turn.
As seen from the chart above, the United States’ wind fleet saw its highest capacity factors around April, roughly corresponding to the nation’s lowest period of electricity demand (Electric Power Monthly, Table 1.2.A). This pushes down on dispatchable generation, causing fossil generators to experience their turbine capacity factors reaching annual lows around this time.
Last year, these factors pummeled coal’s capacity factor below 40 percent in both March and April, allowing wind to slip ahead of it, largely unnoticed, for a brief stretch.
Wind has not yet topped coal’s capacity factor in the fall months, though it made its closest approach in November 2015 (39.0 percent versus 43.6 percent). A combination of mild weather and low natural-gas prices will probably be needed for wind to hit this next milestone.
That said, coal’s capacity factor remains well above that of wind on an annual basis (52.7 percent versus 34.7 percent in 2016), and grid modelers generally take pains to distinguish between intermittent and dispatchable power.
March and April were both marked by higher-than-average wind speeds across key portions of the United States. April’s wind speed anomaly, based on Vaisala’s 5-kilometer (3-mile) resolution Numerical Weather Prediction data set, is reproduced below.