PERFORMANCE RESULTS OF THE FIRST GRID-CONNECTED, THIN-FILM PV INSTALLATION INBRAZIL: TEMPERATURE BEHAVIOUR AND PERFORMANCE RATIOS OVER SIX YEARS OFCONTINUOUS OPERATION

摘要

To investigate the long-term performance of a building-integrated amorphous silicon thin-film PVinstallation in a moist maritime climate with warm winters and hot summers, we designed and installed a 2kWpsystem using frameless BIPV-type, double-junction, same bandgap pin-pin PV modules. The PV system wasretrofitted to a University building that houses the Laboratorio de Energia Solar (LABSOLAR) at UniversidadeFederal de Santa Catarina in Florianopolis (27°S, 48°W), facing true north at latitude tilt. The installation is fully and continuously monitored since start up in 1997, with DC and AC electrical parameters, as well as horizontal and plane-of-array radiation levels and ambient and back-of-module temperatures logged at four-minute intervals. Ourresults demonstrate that after the first year of outdoor exposure, when the Staebler-Wronski degradation effect leadsthe output performance to a stabilised level, the effect of operating temperature on system performance isnegligible. DC and AC performance ratios over the six years of continuous operation reported in this paper wererespectively 91.4% and 81.5%, with back-of-module temperatures reaching over 70°C. We argue that in warm andsunny climates of tropical countries like Brazil, where the building stock in residential suburbs presents large areas suitable for PV integration, the lower conversion efficiency of a-Si PV technology might not be such a drawback (as might be the case in countries like Japan and Germany, where available roof areas are smaller and radiation levels lower), because it is counterbalanced by this technology’s good performance under the high operating temperatures prevailing especially in BIPV applications.