Two-axis tracking fresnel lens solar oven and stove

Abstract

A two-axis tracking solar concentrator system includes a sunlight concentrator, a Fresnel lens, a two-axis solar tracker, sunlight reflectors, an enclosure, a sunlight conversion device, and other components. The lens has very long focal length so that all concentrated sunlight will enter the sunlight conversion device through a small window. The elevation rotation axis goes through the focal point so that the sunlight conversion device will remain at the same horizontal level all the time. The concentrated sunlight makes it easy to achieve a needed temperature. The two-axis tracking design eliminates the need of frequent adjustment. An offset design permits having the sunlight conversion device under shade, so that people do not have to expose themselves to sunlight to do solar cooking. The enclosure significantly reduces the risk of burns and fires. It also makes it very easy to control the heating or cooking process.

What is claimed is: 
     
         1 . A method for converting sunlight to heat or electricity comprising:
 a. receiving sunlight into a solar concentrator enclosure through a fresnel lens having an optical center length and a focal point at a distance longer than the optical center length;   b. reflecting the sunlight within the solar concentrator enclosure at a distance from the fresnel lens approximate to the optical center length of the fresnel lens;   c. passing the sunlight through an sunlight window aperture of the solar concentrator enclosure to the focal point of the fresnel lens; and   d. converting the sunlight into heat or electricity in a sunlight conversion device that is not moving in an elevation direction.