...The Chaska, Minn.-based company Sheer Wind thinks it has a design that could bring the cost of wind power down to a price competitive with natural gas. Daryoush Allaei, Sheer Wind's chief technical officer, told DNews that a utility-scale system of these wind turbines — that is a 100 to 500 MW power plant — the cost could be as low as 1 cent per KWh. For comparison, conventional tower and blade wind power plants cost about 45 to 80 cents per KWh and natural gas plants cost about 2 to 3 cents per KWh.
The company's Invelox captures wind using wide-mouthed funnels. Inside, passageways turn the wind horizontally and taper it into a narrow space, which naturally accelerates the flow. The higher speed wind is then channeled into a turbine positioned at ground level. According to the company, the system works even if wind speeds are slow at the top. For example, a wind entering at 10 mph is increased to 40 mph by the time it enters the turbine. After passing through the turbine, the wind is exhausted back into the environment at 15mph.
The unit is about 50 percent shorter than traditional wind towers and the turbine blades on the generator are 84 percent smaller — as a result, equipment and maintenance costs are lower.