Wind Power
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 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 and ranches that use wind power in lieu of being connected to the grid, to current wind farms consisting of thousands 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 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.
The world's first wind farm consisted of 20 wind turbines and total power capacity of 0.6 MW, installed on Crotched Mountain in southern New Hampshire in December 1980. The Altamont Pass near San Francisco, California, developed in the 1980s, was once the largest wind farm in the world in terms of capacity and still has the largest concentration of wind turbines in the world. Alta Wind Energy Centre in Tehachapi, Kern County, California, is the largest wind farm in the United States with an installed capacity of 1,550 MW. And the Gansu Wind Farm Project in China is the largest wind farm in the world, consisting of a group of 18 wind farms in various stages of construction. Installed capacity as of the end of 2021 was 10,000 MW with a final planned capacity of 20,000 MW when completed.
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, which the NREL estimates has a potential capacity of 4,300 GW in the US, is offshore. Wind speed is generally greater offshore, and wind turbines generally 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. Maintenance costs are also higher. However, offshore land leases tend to be less expensive than purchasing or leasing onshore land. 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 Block Island Wind Farm. This is a 30-megawatt offshore wind farm located approximately three miles southeast of Block Island, Rhode Island, consisting of 5 turbines on fixed foundations. The wind farm is designed to generate over 125,000 megawatt hours annually, enough to power over 17,000 homes. First electricity from Block Island was generated 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.