A parabolic dish concentrator from a telecomunication anttena

In Mexico, Telcom, a big telecommunication company, is removing due to the installation of new systems, hundreds of parabolic antennas made by aluminum and other light materials without further future use. Now, the adaptation of those parabolic antennas as parabolic dishes to be used as solar concentrators for thermal conversion of solar energy is being investigated This paper presents experimental and theoretical advances of research focused on the determination of the focal zone's dimensions and of the optimal shape of the receiver. It is the intent to have low cost, parabolic dishes with high surface's reflectances and high receiver's efficiencies. The antenna's dimensions are 3.32 m in diameter, with focal length of 0.83 m, which gives an aperture angle of 90 degrees. To determine experimentally the deviation of the actual focal zone from the ideal one, a laser scanning technique was used. For the theoretical analysis, a software package for facilitated optical analysis of 3-D distributed solar energy concentrators called CIRCE2 was used The flux distributions for two different shape receivers were analyzed and the error function of the concentrator was determined giving a value of sigma = 2 mad The results indicate that a simplified and cheap system can be built with those antennas to allow the conversion of solar to thermal energy for working temperatures of the order of 1000 K.