A wind energy conversion system (WECS) is any of a variety of mechanisms that are operated by the force of wind against blades or sails that are mounted on a support body that is, in turn, mounted for rotation about a shaft. Wind flowing past the WECS causes the blades to rotate, and such rotation is transferred to an electrical generating means whereby the WECS converts wind energy into electrical energy. WECSs have been proposed and built in a wide variety of types, types such as horizontal axis head on, vertical axis and the like.
While wind energy is considered to be a primary replaceable source of energy, wind energy conversion has not achieved its fullest use for many reasons. These reasons include economics, noise, safety, television interference, and aesthetics, among others. However, one principal reason for such lack of popularity is associated with the low efficiency with which WECSs have converted wind energy into electrical energy.
This low efficiency often manifests itself in large, noisy WECSs that can only be located at special sites. In fact, site location is an important drawback and consideration in WECS design. Wind conditions as well as proximity to population become extremely important design considerations associated with the present WECSs. Such design considerations often limit, or even obviate, the use of WECSs to generate power.
The present inventor has observed that the inefficiency with which present WECS designs convert wind energy to electric power is associated with several design characteristics of such present WECSs. These design characteristics include support body shape, blade shape as well as blade location on the support body.
In the past, the blades of a WECS have been straight, that is, similar in shape to the blade illustrated in FIG. 1. The shape of the prior blades has inhibited the efficiency of the energy conversion process in many situations. In some instances, the blade is erroneously oriented with respect to the wind, and thus is inefficient for one situation while being efficient for another. It has also been found that these present blades are subject to a variety of extraneous loads, that result in lead-lag motions, flapping and/or pitching. These motions generally reduce the efficiency of a WECS, and may cause damage to the machine. Such motions may also influence the overall design of the WECS in an adverse manner. Furthermore, the blade shape and orientation of present WECSs does not make efficient use of the wind energy in many situations, situations such as varying wind conditions that vary over the blade as an entity or at various locations on the blade. The blade shape and orientation may also create turbulence, or like air flow disruptions adjacent to the blade. Such air flow disruptions can inhibit the efficiency of a WECS.
In addition to being straight, many of the prior art WECS blades are located in a position on the supporting body that prevents the blades from being as efficient as possible. For example, some blades are located at the up-wind location on the body as illustrated in FIG. 2, while others are located at the down-wind end of the supporting body as illustrated in FIG. 3. The inventor has found that locating the blades as illustrated in FIGS. 2 or 3 does not make the most efficient use of the air flowing past the system, and, in some instances, may even inhibit the efficiency of the overall device. In fact, the inventor has found that, in addition to failing to make the most efficient energy conversion, the location and shape of the blades on present WECSs may actually exacerbate inefficient operation in some situations.
Therefore, there is a need for a wind energy conversion system that makes more efficient use of wind energy than presently-available wind energy conversion systems. Specifically, there is a need for such a WECS that has the blade-supporting body thereof and the blades thereof designed to operate in the most efficient manner for a wide variety of situations.