Dear Solar Guy, Some areas of the state are windier than others. How windy does it have to be for wind energy to be economical? Windy Rivers, Muleshoe, TX. ----------------------------- Dear Windy, The amount of electrical power obtained from the wind varies as the cube of the wind speed. This means if the wind speed increases from 10 to 13 mph (increases by 30%), the potential power would increase by a factor of about 1.3 x 1.3 x 1.3 = 2.2. Therefore, such a modest increase in wind speed results in a large increase in potential power output. In this case the cost of the electricity obtained would be decreased by a factor of about 2.2 for the higher speed case ..... thus a very substantial improvement in economics. Another factor is the cost of competing power. It isn't really possible to specify a threshold wind speed above which wind energy is economical. But currently, wind systems in the Delaware Mountains of west Texas produce economic power to feed into the grid with the average wind speeds of about 22 mph that prevail there. A location with at least 20 mph average wind speed should produce competitive electricity for the grid. On the other hand, for small-scale applications which are not close to the grid, average wind speeds of 15 mph or higher will result in economic wind energy. Note this 1.33 to 1 ratio between the speed for the two applications (15 vs 20) results in about a 2.35 to 1 ratio in power. Thus, even though the lower wind speed stand-alone site has a smaller wind energy potential, it is economical because it doesn't have to compete with cheap power from the grid. Hope you have a good site nearby. The Solar Guy P.S. Texas has very good-to-excellent wind energy potential in many regions. There are several companies supplying wind energy equipment in Texas and there are several major wind projects completed or in progress by electric utilities in the state, including those by CSW, TxU and LCRA. Also, West Texas A&M University in Canyon operates a major wind energy test facility.