A wind turbine’s performance – how much electricity a wind turbine produces compared to its maximum possible production – is almost entirely dependent on the availability of wind resources, which depend on both the time of year and the geographic region.
A power plant’s output is often expressed as a percentage of the maximum possible production in a given period of time, a metric known as capacity factor. Nationwide, between January 2016 and August 2022, wind turbine capacity factors peaked in March and April and were lowest in July and August.
Unlike fossil fuel power plants such as coal or natural gas power plants, wind power plants have no fuel costs to generate electricity, so the electricity they produce is almost entirely determined by the available wind resources. The performance of wind turbines is not only influenced by wind speed, but also by wind direction, wind stability and turbine height.
Due to geographic differences in wind resource potential, wind generation varies from region to region. We grouped states into regional groups that share similar wind capacity factor patterns. The Lower Plains region of Texas, Oklahoma, Kansas and New Mexico has the largest share of US wind capacity at 44% (as of August 2022). Due to the concentration of wind capacity in the Lower Plains, the national wind power pattern closely follows the seasonal wind power pattern of the Lower Plains: power peaks in spring, decreases in summer, and increases again in fall and winter.
The Upper Plains region has the second largest share of US wind capacity at 29%. The Upper Plains also generally follow the same seasonal pattern as the Lower Plains.
The Interior East region (13% of US capacity) follows the same pattern, but with a larger drop in the summer months than the Lower and Upper Plains.
The seasonal pattern is quite different in the West Coast region (10% of US wind capacity), where the pattern is primarily driven by a concentration of wind capacity in California. Wind capacity factors in the west coast region increase later in the spring and peak in the summer months before steadily decreasing in the fall and winter. This pattern results from the interaction of cold air from the Pacific current with ocean breezes and the location of California’s wind turbines, which are generally located near coastal mountain passes.
The Southwest, East Coast and New England have capacity factors slightly below the national average and have fewer wind turbines. Collectively, these three regions accounted for 4% of the country’s wind capacity as of August 2022.
We publish data on capacity, generation and capacity factor at national level in our Electricity monthly. We publish state-level statistics in our state power profiles. Many data series are also available in our Electric Data Browser.
Main responsible: M Tyson Brown