Living organisms require available energy to stay alive, such as the energy humans get from food. Civilisation gets the energy it needs from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The processes of Earth's climate and ecosystem are driven by the radiant energy Earth receives from the sun and the geothermal energy contained within the earth.
Wind power in an open air stream is thus proportional to the third power of the wind speed; the available power increases eightfold when the wind speed doubles. Wind turbines for grid electric power therefore need to be especially efficient at greater wind speeds.
Wind is the movement of air across the surface of the Earth, affected by areas of high pressure and of low pressure.
The global wind kinetic energy averaged approximately 1.50 MJ/m2 over the period from 1979 to 2010, 1.31 MJ/m2 in the Northern Hemisphere with 1.70 MJ/m2 in the Southern Hemisphere. The atmosphere acts as a thermal engine, absorbing heat at higher temperatures, releasing heat at lower temperatures. The process is responsible for production of wind kinetic energy at a rate of 2.46 W/m2 sustaining thus the circulation of the atmosphere against frictional dissipation.
Through wind resource assessment it is possible to provide estimates of wind power potential globally, by country or region, or for a specific site. A global assessment of wind power potential is available via the Global Wind Atlas provided by the Technical University of Denmark in partnership with the World Bank.
Unlike 'static' wind resource atlases which average estimates of wind speed and power density across multiple years, tools such as Renewables.ninja provide time-varying simulations of wind speed and power output from different wind turbine models at an hourly resolution.
More detailed, site specific assessments of wind resource potential can be obtained from specialist commercial providers, and many of the larger wind developers will maintain in-house modeling capabilities.