Overview of Wind Energy
How is wind created?
Uneven heating of the Earth’s surface by the sun causes the wind. The warmer air in some places rises. The resulting low pressure area draws in cooler air.
Wind patterns are affected by the spin of the planet, weather patterns, and terrain.
Wind energy potential increases very rapidly with increasing wind speed. If fact, if wind speed doubles the energy content goes up by a factor of eight.
Wind systems and cost.
The costs of small wind turbines has not dropped very much in the last 15 years, principally because small wind systems have not been granted the subsidies that are available for large wind turbines and solar modules.
Because of new U.S. subsidy programs for purchasers of small wind turbines and new technology breakthroughs, the future prospects for cost reductions in small wind turbines are the best they have been in twenty years.
Homeowners in California and Illinois can now receive rebates or grants covering over half of the installed cost of a small wind turbine. Similar programs are emerging in New Jersey, New York, and Massachusetts. Other states will follow.
How can we use wind?
Large wind turbines are used primarily in arrays, called “windfarms.” These huge machines require high wind resources because they must compete with conventional generation (coal, natural gas, oil, and nuclear) at the wholesale level. Large wind turbines are generally not used in “off-grid” applications.
Small wind systems are used primarily for individual homes, businesses, or facilities; on-grid or off-grid. Though they cost relatively more than large turbines, small wind turbines can be used in areas with modest wind resources because they compete at the retail level.
The future of large wind systems.
Large wind turbines have gotten much bigger and much less expensive in the last 15 years. They can already produce electricity less expensively than power from coal or nuclear power plants. Some experts expect large wind turbines to be the least expensive way to produce electricity within ten years.