The wind is rapidly becoming a practical source of energy for electric utilities around the world. In the U.S., development of commercial wind power plants (also referred to as wind power stations) has been carried out largely by independent firms operating under the 1978 Public Regulatory and Policy Act (PURPA) either as independent power producers (IPP) or as qualifying facilities (QF). In the post-2000 period utilities have been investing directly in wind power plants and operating them like conventional generation. In the early 1980s utilities were concerned about many technical and economic issues regarding the integration of wind power plants into existing grids, which are highly-interactive networks of generating stations, transmission lines, and distribution wires. They feared possible adverse impacts from wind generation on critical performance and economic factors such as power quality, grid stability, automatic generation control, spinning reserve requirements, and capacity credits. As operating experience with wind power plants accumulates, many of these early fears are being dispelled.
Since 1980 the installed capacity of wind power plants in the United States has grown dramatically surpassing 25,000 MW in 2008. This rise was kindled by financial incentives from federal and state governments and by rising prices for fossil fuels. More of this rapid growth is expected in the future, as other climate change drives the low carbon and other emission reductions. A similar process began in Europe in the early 1990s, and installed wind capacity there grew faster than the United States, driven by clean energy concerns and the lack of indigenous fossil fuel resources. By the end of 2007, installed capacity in Europe had exceeded 57,100 MW, 61 percent of the global total. World-wide, wind turbines totaling almost 100,000 MW of capacity are now generating 184 TW-hr of bulk power annually.