Design and testing of a low-level concentrator

Abstract

One way to promote the increased use of renewable energy technology for the purpose of energy production is to drive down the cost of renewable energy on par or even less than energy derived from fossil fuels. One technology which has the potential to meet this requirement is concentrated photovoltaic technology. As such, the scope of this dissertation was to investigate photovoltaic concentrator systems with particular note to low-level concentrators. As part of the study, a prototype system was designed and constructed in order to investigate its performance. The prototype system consisted of a concentrator module which holds up to four Fresnel lenses that concentrate sunlight on to the receiver. The module is mounted onto a dual-axis tracker which maintains its orientation directly perpendicular to the incident radiation from the sun. An experiment carried out in this study over a number of days was used to compare the energy delivered by four identical poly-crystalline solar cells subjected to different conditions. The cumulative energy output of a cell fixed in a south-facing orientation, and inclined at 45∘, was used as a reference to calculate the percentage change in the cumulative energy output of the three other cells: one tracking the sun on both axes and another two receiving concentrated illumination through the use of the Fresnel lenses. These last two cells, which tracked the sun as well, were mounted on different heatsinks to investigate the effect of heat on cell performance. The results showed that the cell mounted on the large heatsink, and subjected to concentrated illumination, performed the best with an average percentage increase of 63.60% over the cumulative energy output of the non-tracking cell.