Renewables form an essential source of energy for America, and wind power is their rising star. During the past two decades, wind-generated power moved from a negligible source to supplying over 40 percent of the electricity produced from renewables. Wind toppled hydroelectric in 2019 as the most-used renewable energy source for electricity generation.
Power from renewable sources provided 17.5 percent of all U.S. electric power in 2019, according to the U.S. Energy Information Administration (EIA). Electricity produced from coal declined by half during the past dozen years, but renewables and natural gas grew. Renewables doubled their share of the market during that period, primarily thanks to wind power.
Wind blowing keeps electricity flowing
Humans unlocked wind power when our ancient ancestors first used sails to power their boats across open waters. But harnessing that natural energy and converting it into electricity on a commercial scale is a relatively new phenomenon. The technology for building massive turbines capable of supplying industrial power came into its own in the early 1980s.
These modern turbines rise hundreds of feet above the ground and support massive blades up to 200 feet (60 meters) in length. Those blades rotate as the wind blows across them, and the turbines produce electricity. So, wind speed controls the amount of power a turbine produces.
Optimal wind speeds for turbines are between about 30 to 55 miles per hour. However, if wind speeds are much higher than 55 miles per hour, the turbines need to shut down to avoid mechanical damage. Likewise, they won’t produce electricity if the wind speed drops too low. But the power produced is not directly proportional to wind speed. The turbine output is equivalent to the cube of wind speed, so if wind speed drops by half, then power output falls by about 88 percent.
How much power?
The USA is the second-largest producer of wind-generated electricity in the world with an installed capacity of about 100 GW (Gigawatts). China holds the first place spot
USA wind power generated 300 billion kilowatt-hours (KWh) of electricity in 2019 from approximately 58,000 turbines, about 5.2 million KWh per turbine. So, each turbine is powering 470 homes according to the EIA’s estimates of average home electricity needs.
Geography and altitude
Higher wind speeds mean more electricity, but we can’t bring the wind to us, so wind farms must go to where the wind blows. It turns out that this is a function of both geography and altitude.
Onshore wind farms face an altitude problem. Close to the ground topography, trees, and buildings disrupt the wind flow and make wind power generation less effective. This disruption creates the need to mount wind turbines high in the air to avoid ground disturbances. Of course, going higher cost more, so prudent operators must reach a balance. In, 2018 the average height of new wind turbines was 290 feet.
More critical than altitude is geography. Some places get more wind than others. For the United States, the sweet spot is a north/south trending swath of States stretching from the Dakotas to Texas. The map below shows average annual wind speeds at 262 feet above ground level. The purple and red areas represent the fastest wind speeds. Four of the five states with the largest share of wind-generated electricity are in this sweet spot.
Economics
Wind power benefits from government subsidies, but so do solar and fossil fuels. However, these wind power subsidies start phasing out in 2020. This loss of profit will affect the expansion of wind farms but probably won’t stop the addition of future wind generation capacity. Several large European projects are currently proceeding without subsidies. The consensus is that the loss of subsidies will make wind less competitive but not uncompetitive.
Coal use for electricity generation has steadily declined for six straight years, and its market share fell from about 50 percent to 23 percent in the last decade. But as coal consumption dropped, natural gas and renewables stepped in to fill the gap, and the wind has been the shining star of growing renewable resources. The economics will get tougher as subsidies phase out, but wind power still has a bright future.
ArcheanWeb:
Can we quit fossil fuels? (Source: ArcheanWeb) – https://archeanweb.com/2020/01/23/can-we-quit-fossil-fuels/ Also:
Coal slumps as renewable energy surges (Source: ArcheanWeb) – https://archeanweb.com/2020/06/16/coal-slumps-as-renewable-energy-surges/ Also:
Sources:
Electricity explained – Electricity in the United States (Source: U.S Energy Information Administration) – https://www.eia.gov/energyexplained/electricity/electricity-in-the-us.php Also:
How Much Power Does a Wind Turbine Generate? (By Kevin Lee; Sciencing) – https://sciencing.com/much-power-wind-turbine-generate-6917667.html Also:
The top 10 countries in the world by wind energy capacity (By Jack Unwin; Power Technology) – https://www.power-technology.com/features/wind-energy-by-country/ Also:
Wind explained: Where wind power is harnessed (Source: .S Energy Information Administration) – https://www.eia.gov/energyexplained/wind/where-wind-power-is-harnessed.php Also:
Does Wind ‘Work’ Without Subsidies? (By Jessica McDonald; FactCheck.ORG) – https://www.factcheck.org/2019/07/does-wind-work-without-subsidies/ Also:
Feature Image: Blood Hill wind farm (Modified) – By Stephen Craven, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=4851226