Since then researchers have been experimenting with innovative new windmill designs. Besides streamlining the conventional multiblade windmills to ones with only two or three blades and equipping them with servomotors to keep them facing the wind, other designs also look hopeful. The Darrieus and Savonius rotors can draw energy regardless of the wind direction. The eggbeater shape of the Darrieus and the S-shape of the Savonius allows them to not need servomotors to rotate them with the wind. In tests the Darrieus windmills have been found to be more efficient and less expensive than propeller types.
Wind power looks to be one of the most promising of the alternative sources of energy.
New designs in windmills make them more efficient. They do not take up a great deal of land. It is a very clean process. The initial costs of a wind farm are about half the cost of a nuclear power plant that produces the same amount of energy. Though the feasibility of using solar energy is constrained by location, weather and time of year in many parts of the world solar energy is a competitive resource.