Wednesday, June 17, 2009

How To Get Wind Turbines To Work Harder

From ScienceDaily:
How much usable energy do wind turbines produce? It is a question that perplexes engineers and frustrates potential users, especially on windless days. A study published this month in the International Journal of Exergy provides a formula for answering this vexing question....

...Ahmadi and Ehyaei point out that wind turbines have to compete with many other energy sources, primarily fossil fuels but also other renewable energy sources such as solar and biomass technology. As such, a wind turbine has to be cost effective in order to be environmentally effective....

...They have carried out an exergy analysis of turbines sited in two cities in Iran, Tehran and Manjil, where wind speeds are very different. Tehran has low average wind, whereas Manjil is a windy city. Their formula offers optimized values for wind turbine rotation speed, which can be altered depending on wind speed. The results are a theoretical boost of 20% efficiency at both sites and a decrease in "wasted" energy of 80%....MORE