Concentrating photovoltaic systems

The first section of this chapter introduces the principles of concentrating photovoltaic (CPV) technology. Since there is a huge diversity in system designs, the most common principles are outlined and examples for CPV systems are presented. The second section discusses the most important impacts on the performance of CPV systems. In contrast to standard photovoltaic (PV), the influence of the cell temperature on the output power is much less important. On the other hand, multijunction solar cells are used in high-concentration systems and therefore daily and seasonal changes in the spectrum have a stronger impact on the energy output compared to flat-plate PV. However, it is discussed that these effects must be seriously considered for the instantaneous power output but over a full year of energy production there is an averaging effect and the most dominant influence remains the irradiance. Sections 10.3 and 10.4 deal with the evaluation of CPV technology. Here, stand ards are an essential prerequisite. International Electrotechnical Commission standards for CPV technology are currently under development and drafts are already published. The sections give insight into the standards and detailed information about the benefits of these standards and provide examples of how to use them. Further, recent results of module, system and power station evaluation, applying these standards for the first time, are presented.