ESTIMATION OF THE INFLUENCE OF DEW CONDENSATION ON ANNUAL ENERGY GENERATION OF A CONCENTRATOR PV SYSTEM: ANALYSIS OF DATA OVER TWO YEARS

摘要

In our previous analysis, using data from June 2004 to May 2005, we found that the annual energy generation of our concentrator photovoltaic (CPV)system was reduced by 1.2% by dew condensation. To clarify the influence of dew condensation on the energy generation, the present study performedadditional analysis using new data from °Ctober 2005 to September 2006, and compared the results to those of the previous analysis. The °Ccurrence of dewcondensation was derived from daily curves of the module efficiency and fill factor of the CPV system. The daily energy generation of the system wasestimated by correcting the measured values of the module efficiency to the ideal value for the same month. Because the module efficiency of CPV systemsusing three-junction cells is strongly influenced by seasonal variations in the spectrum of direct solar irradiance, ideal daily efficiency curves were createdeach month using data measured for days with clear skies. It was found that the reduction in annual energy generation of the CPV system was 2.0%,whereas it was 1.2% in the previous study.