Effects of environmental factors on the conversion efficiency of solar thermoelectric co-generators comprising parabola trough collectors and thermoelectric modules without evacuated tubular collector

摘要

Solar thermoelectric co-generators (STECGs) are an attractive means of supplying electric power and heat simultaneously and economically. Here we examine the effects of environmental factors on the conversion efficiencies of a new type of STECG comprising parabolic trough concentrators and thermoelectric modules (TEMs). Each TEM array was bonded with a solar selective absorber plate and directly positioned on the focal axis of the parabolic concentrator. Glass tubular collectors were not used to encase the TEMs. Although this makes the overall system simpler, the environmental effects become significant. Simulations show that the performance of such a system strongly depends on ambient conditions such as solar insolation, atmospheric temperature and wind velocity. As each of these factors increases, the thermal losses of the STECG system also increase, resulting in reduced solar conversion efficiency, despite the increased radiation absorption. However, the impact of these factors is relatively complicated. Although the electrical efficiency of the system increases with increasing solar insolation, it decreases with increasing ambient temperature and wind velocity. These results serve as a useful guide to the selection and installation of STECGs, particularly in Guangzhou or similar climate region.