Mother Earth News recently published a guide to vertical axis wind turbines at their site. Vertical axis wind turbines have been in the news lately, from the Bluenergy SolarWind Turbine, to the Nova Aerogenerator, to Mariah Power’s new Windspire, which is about to start one year of rigorous performance testing with the National Renewable Energy Laboratory (NREL) in Colorado.
The Mother Earth News article goes into quite a bit of depth on these turbines – explaining in detail the different principle designs (Savonius rotor and the Darrieus model), but their overall assessment is not good. The bottom line seems to be that vertical axis wind turbines (or VAWT’s) are “less efficient, and it takes more materials and labor to make the things.” According to the author while responding to the question, “Are there any situations in which a vertical model would be a better choice than a horizontal?,” the answer is, “Not today. Simply because there’s nothing reliable, there’s nothing cost-effective, there are no performance results, there’s no reality. That could change.”
However, they acknowledge that people are coming up with new VAWT designs all the time – there’s room for less efficient designs if the final price is right. He “honestly thinks that in a year or two, we may see a design that actually works and works for 20 years or so like it should.”