Physorg: A quiet wind turbine developed in Scotland is now available in the US and Canada. Its developers say that the roof-based turbine can provide significant power for homes and commercial buildings alike. Originally designed by Scotland-based Renewable Devices, the Swift wind turbine is being sold in the US by Cascade Engineering of Grand Rapids, Mich. Unlike many existing small wind turbines, the Swift turbine is designed to reduce noise. At seven feet in diameter, it consists of …