Wind Power Now US’s Most-Used Renewable Energy Source

In 2019, annual wind generation in the U.S. exceeded hydroelectric generation for the first time, with wind power the country’s top renewable power source, the Energy Information Administration reports.

Annual wind generation totaled 300 million megawatt-hours (MWh) last year, exceeding hydroelectric generation by 26 million MWh. Wind generation has increased steadily during the past decade, in part, because of the Production Tax Credit (PTC), was extended.

Annual hydroelectric generation has fluctuated between 250 million MWh and 320 million MWh in the past 10 years, indicating a stable capacity base and variable annual precipitation.

Additions 10,000 MW

Wind capacity additions tend to come online during the fourth quarter of the year, most likely because of tax benefits, according to EIA. Wind capacity additions totaled 10,000 megawatts in 2019 (3,800 MW installed in the fourth quarter), making 2019 the second-largest year for wind capacity additions, second only to 2012. As of the end of 2019, the U.S. had 103,000 MW of wind capacity, with 77% installed in the past decade.

The U.S. has 80,000 MW of hydroelectric capacity, most of which has been operating for several decades. Only 2,000 MW of hydroelectric capacity has been added in the past 10 years, and some of those additions involved converting previously non-powered dams.

Annual changes in hydroelectric generation are primarily the result of variations in annual precipitation patterns and water runoff. While weather patterns also affect wind generation in different regions, capacity growth has been the predominant driver of annual changes in wind generation.

Hydropower greatest during spring

Hydroelectric generation is typically greatest in the spring when precipitation and melting snowpack increase water runoff. Seasonal wind patterns vary across the country, but wind generation is usually greatest in the spring and fall, according to EIA.

Although total installed wind capacity surpassed total installed hydroelectric capacity in 2016, but it wasn’t until last year wind generation surpassed hydroelectric generation.

The average annual capacity factors for the hydroelectric fleet between 2009 and 2019 ranged from 35% to 43%. The average annual capacity factors for the U.S. wind fleet were lower, ranging from 28% to 35%.

Capacity factors are the ratio of the electrical energy produced by a generating unit for a specified period of time, to the electrical energy that could have been produced at continuous full power operation during the same period.