Using the energy of the wind to drive the sails of a windmill and generate power, either mechanical or electrical. Wind-driven turbines attached to the sails convert wind energy into electricity. The electrical energy may be stored in a battery to provide constant energy supplies independent of wind conditions.
Wind turbines may be used a stand-alone electricity supply (with battery storage) or connected directly to a main power grid. Wind energy is an attractive renewable energy option in regions characterized by windy environments.
Fossil fuels are finite and are responsible for a significant amount of the world's pollution and environmental degradation. In comparison to fossil and nuclear based energy, renewable energy sources such as wind power cause negligible environmental degradation, and will sooner or later necessarily need to be relied upon for energy and for sustainable development.
Wind power is becoming more popular throughout rural Europe. An offshore wind farm has been constructed in Denmark, which aims to producing 50% of its national electrical needs from wind by 2030.
India aimed towards having the equivalent of more than 3,000 average-sized turbines working by the end of the 1990s.
California's 16,000 turbines provide enough electricity to power all the homes in a city the size of San Francisco. During the 1990s, wind power capacity in the United States grew by an average of 26% per year, with 35% growth in 1998, making it the fastest growing electricity sector. In 1999 the US Energy Secretary announced plans to increase wind power generation in the US to meet 5% of its electricity needs by 2020. It was reported in 2001 that the second largest wind farm in the world will be constructed on King Mountain in Texas. Over a 20 year life the facility is expected to prevent 20 million tons of carbon dioxide that would be generated by a fossil-fuelled power plant.
In real terms, wind power can probably never provide more than 10 or 20% of the US supply, as it cannot really replace base-load plants. In addition, the windiest places in the US are usually far from where energy demand is greatest and transmission lines are costly.