Diversified Electricity Generation
Wind power generation technologies have experienced significant growth in recent decades. Today’s wind farms range from dozens up to thousands of electricity-producing wind turbines. The largest wind farm in the world is the Gansu Wind Farm in China, which has a projected generation capacity of 10 GW from around 7,000 turbines. The Alta Wind Energy Center in California is the largest wind farm in the United States, with a 1.5 GW generation capacity.
The global installed capacity of wind power generation grew from approximately 59 GW in 2005 to 432 GW in 2015, according to the Global Wind Energy Council (GWEC). As of 2015, the countries with the largest cumulative wind generation capacity were China with 33.6 percent of the total capacity, followed by the United States with 17.2 percent and Germany with 10.4 percent.
While the vast preponderance of wind generation facilities are on land, offshore wind generation tripled in capacity from 2011-2015. Although offshore generation accounted for only 12 GW in 2015, primarily in the United Kingdom and Germany, it represents an emerging area of innovation and development.
The cost of wind power has dropped by an average of 7 percent per year since 1985, comprising an overall cost reduction of over 90 percent during that period. Wind is becoming an increasingly important part of the power generation mix, especially in Europe. Denmark generates approximately 40 percent of its electricity demand via wind power. It has a 20 percent penetration in Portugal, Spain, and Ireland, and has reached 5.6 percent in the United States. Remarkably, wind accounts for nearly 45 percent of the electrical power in Texas during peak conditions.
Technological advances in both blade and tower design and materials sciences have provided efficiency gains and cost reductions for wind power. At the simplest level, taller towers are more productive and allow greater geographic coverage of onshore wind turbines. Capacity factor, which reflects the fraction of the year that a turbine is operating at peak power (average output/peak output), is the most common measurement of turbine efficiency. The capacity factor for US wind projects increased from 31.2 percent during 2004–2011, to 41.2 percent in 2014, and is continuing to increase. General advances in manufacturing, construction technology, and techniques benefit the wind power industry directly, as do materials that allow for lighter turbines—all of which will continue to increase the economic viability of wind-based power generation technologies.