Abstract: Wind turbine rotors and wind turbine blades having the startup capability of a drag-type turbine and the increased tip speed of a lift-type turbine are provided. The rotor includes a plurality of elongated blades, each of the blades having a first portion mounted to a mast at a first radial distance from the mast and a second portion mounted to the mast at a second radial distance from the mast, less than the first radial distance. Each blade includes a first chord length, a second chord length, and a third chord length between the first and second chord length. The third chord length is less than the first chord length and less than the second chord length. The blades may be helical. Aspects of the invention provide a self-starting, Darrieus-type rotor for enhanced wind energy capture.

Abstract: Methods and systems for providing wind energy density for a location, for example, for locating a wind turbine at the location are provided. The method includes the steps of a) providing a location for consideration; b) identifying at least one meteorological station, for example, nearest the location; c) determining a wind speed for the at least one meteorological station; d) determining surface roughness characteristics of an area around the at least one meteorological station; e) calculating geostrophic wind speed about an area around the at least one meteorological station from the wind speed and the surface roughness characteristics of an area around the at least one meteorological station; f) determining surface roughness characteristics of an area around the location; and g) calculating a wind energy density for the area about the location from the calculated geostrophic wind speed and the surface roughness characteristics of the area around the location.