Wind energy takes advantage of a renewable resource that is in great supply in many parts of the world, wind. It requires no combustion, is non-polluting and, except during original fabrication, emits no greenhouse gasses. Wind has been used throughout history to provide power, from the earliest sailing vessels that used it for transportation, to medieval windmills that used wind to grind grain or pump water, to isolated farms, ranches, and homes that use wind power for electricity in lieu of being connected to the grid, to current wind farms consisting of hundreds of wind turbines that supply power to the electric grid.
However, wind power does have a number of challenges. Since power generation depends on wind speed, which is not constant, its feasibility in some geographic locations is limited. In general, an average wind speed of over 10 mph (4.5 m/s) is required. In addition, the most suitable areas for wind power tend to be located great distances from major cities which requires investment in transmission infrastructure. And, since the wind generally blows harder at night, power generation is maximum at the time when power demand is relatively low. Other issues that must be overcome are the fact that large land areas are required and the perception that wind farms are an eyesore.
According to the NREL (National Renewable Energy Laboratory), the United States has a theoretical onshore wind potential capacity of 11,000 GW. This compares to a total US electricity capacity of approximately 1,000 GW. Thus, less than 10% of total theoretical capacity could meet all electrical power needs in the US. At the end of 2021, the US had a cumulative 136 GW of installed wind energy capacity out of a total 839 GW worldwide. Although this was enough for the US to be the second-leading market in terms of cumulative capacity, behind China, wind still only supplied 9.1% of total electrical consumption.
The new frontier for wind development is the offshore, which the NREL estimates has a potential capacity of 4,300 GW in the US. Wind speed is generally greater offshore, and wind turbines typically don't compete with other uses for the site. Development costs tend to be higher as the design is more challenging, installation requires additional specialized equipment, and transmission lines must be laid underwater. Europe has taken the lead in developing offshore wind farms, with large developments in the UK, Germany, Denmark, and Portugal. The largest offshore wind farm in the world at the end of 2021 was Hornsea 2, located off the Yorkshire coast of the UK, with capacity of 1.3 GW. The first offshore wind farm to start operation in the US is Deepwater Wind's 30-megawatt Block Island Wind Farm which began generating electricity in December 2016.
Given the technological advances that have occurred over the last several decades, unsubsidized new onshore wind developments at the end of 2021 cost, on average, less than the least expensive new plant using conventional sources, which is a gas-fired combined cycle plant. At the low end of the cost range, i.e., in those locations and conditions that are best suited for wind power, new wind power with available subsidies is cheaper than running an existing combined cycle plant.
Given its renewable and non-polluting nature, decreasing cost, and political and social pressure to address climate change issues, demand will undoubtedly continue to increase for wind power.
The Wind Power Topics package provides information on a variety of wind power topics of general interest to the American public. Key references are provided that can be used to find more detailed information.