Design and Construction of a Parabolic Dish in Mexico

A parabolic dish concentrator for electricity generation is currently under development at the Instituto de Investigaciones Ele´ctricas (IIE) of Mexico, a government-owned research organization. The concentrator is 7.5 meters in diameter with focal length to diameter ratio of 0.6. The reflective surface consists of 12 facets made of fiberglass with a reflecting surface made of aluminum sheet with a solar reflectance of 86%. The system will use a 9 kW Stirling engine to produce electricity from concentrated solar radiation. The paper describes preliminary and final design characteristics of the parabolic dish structure. Criteria for facet design, material selection, and structural configuration are reviewed. A detail explanation of tooling, substrate preparation and facets assembly is also presented. The key features and requirements of the tracking system, Stirling motor and control unit are also described.