Design and development of an environment for photovoltaic module efficiency tests under different conditions of radiation and temperature
Willi Gonçalez Osaka1; Luís Mauro Moura2; Wellington Meira Dancini dos Santos1
1 IFPR; 2 PUCPR
doi:10.20906/CPS/COB-2015-1588
Resumo
Besides the significant potential of solar photovoltaics (PV) technology in Brazil, some characteristics have limited your more expressive growth, such as low efficiency of PV cells, long time of return on investment and uncertainties about its real performance. This occurs because PV efficiency evaluations are carried out in laboratories to simulate environmental conditions and uses fixed values in accordance to NBR 12136, which does not represent the most Brazilian weather conditions. In this process important parameters to evaluate PV efficiency are neglected, such as the temperature, wind speed and irradiation, resulting in a significant difference between the nominal and real efficiency. The main goal of this work was design and develop an indoor evaluation environment which was able to perform studies and simulations on its efficiency by optimizing its thermal and radiative properties. This environment was built using a matrix 6x4 of 500 W halogens lamps, resulting in 12 kW. All the lamps were controlled by a PWM circuit of 12 kW, which allowed the radiation adjustment of the solar simulator. This apparatus was inserted in a chamber of the Thermal Systems Laboratory (LST) of PUCPR, in order to stabilize the room temperature at 25 ° C and reduce external interference on the results, such as the wind speed and shadows caused by clouds. The measurements were performed by a charge controller (Maximum Power Point), a pyranometer to measure radiation in the photovoltaic module, thermocouples to measure the temperature in several points of the module and anemometer to measure the wind speed. To validate the indoor evaluation environment was defined a mathematical model for predicting the PV module efficiency and describe its behavior in accordance to temperature rises. The results showed a significant correlation between the mathematical model and the experimental results obtained with the solar simulator.
Palavras-chave: PV; efficiency; temperature