Electrical Rating--Long-Term Performance Potential of Photovoltaic Systems

Owing to diverse photovoltaic technology and dynamic nature of meteorological data, a number of factors affect the performance of photovoltaic systems. The highly efficient concentrated photovoltaic (CPV) system can only respond to beam radiations of solar energy, unlike stationary silicon-based conventional photovoltaic (PV) panels. The availability of solar energy, and share of beam/diffuse radiations, varies from region to region, depending upon weather conditions. However, the rated performance as instantaneous maximum efficiency at STC (standard testing conditions) or NOCT (nominal operating cell temperature) in the laboratory, does not depict the true system performance under changing field conditions. The energy planners are interested in actual field performance, in terms of total delivered energy. Therefore, despite highest efficiency, CPV installations seem to be limited to desert regions, with high beam radiations availability and favorable working conditions. In this chapter, the performance potential and feasibility of CPV system is reported for long term operation in tropical weather conditions, in terms of proposed electrical rating parameter, giving total energy delivered as kWh/m2.year. From 1-year field operation of two in-house built CPV units, electrical rating of 240.2 kWh/m2.year is recorded for CPV operation in Singapore, the first ever reported CPV performance in this region, which is two folds higher than the stationary PV.