An analysis of the potential of Wind Energy Conversion Systems

Abstract

Wind Energy Conversion Systems (WECS) are solar systems because the sun drives the atmospheric circulation. About 20 TW of wind energy flows poleward annually, over land in temperate latitudes, in the 500 m deep atmospheric boundary layer. An average 500 GW of electricity could be generated by massive exploitation of the U.S. Great Plains wind field. There are, however, large fluctuations in available wind power. There are frequent 20% variations in annual supply; annual periodicity brings most wind power during the spring; there are storm cycles; and there is a diurnal cycle. Gusts and turbulence also require filtering to meet normal power requirements. Several schemes are evolving to tame this erratic wind power supply. Modern technology is refining horizontal-axis turbines of a wide size range. Progress is also being made toward producing an economical vertical-axis turbine. Standards for turbine performance evaluation and installation site selection are now being developed. Yet it will be a few years before proven systems can significantly affect national energy supplies. Eventually, mass-produced WECS may cost $1000 per installed, rated kW, but the wind does not often flow at turbine-rated speed. With some storage or filtering, problems with wind variability may be overcome. Then WECS electricity production may be as economical as other electric generators. No serious hazards or environmental impacts should slow WECS development.