Impactos da temperatura e irradiância em células solares de silício policristalino

Abstract

The accurate knowledge of the solar cells parameters dependence on irradiance and temperature is of vital importance for the performance assessment of photovoltaic modules and development of new devices. Many works have been published so far to understand the aforementioned dependence, but significant discrepancies have been found. Therefore, in order to clarify these discrepancies, the temperature and irradiance impacts on seven polycrystalline silicon solar cells were studied through a minutious experimental characterization in the range 600-1000 𝑊/𝑚2 and 25-55oC, using a solar cell characterization platform equipped with vacuum chunk and temperature control, developed during this work, and posterior computational extraction of the single diode parameters using the Differential Evolution optimization technique, resulting in a very low fitting error between experimental and simulated I-V curves. The results indicated that the temperature effects are stronger for all the single diode parameters except for the photocurrent. Series resistance was found to be better described by an exponential decrease with increasing temperature, remaining almost constant as irradiance changed. Shunt resistance showed a linear decrease for increasing temperature, and remained almost constant for different irradiances. The diode saturation current exhibited an exponential increase for higher temperature values and remained almost unchanged for increasing irradiance. The diode ideality factor remained almost unchanged for both temperature and irradiance changes. The photocurrent showed a linear increase for both temperature and irradiance increase, but it was much more accentuated for the latter. Also, it was observed that the errors and uncertainties associated with the characterization procedure and parameter extraction were small, so that the employed methodology produced results that can be regarded as reliable representatives of the real behavior of polycrystalline silicon solar cells under the temperature and irradiance range studied.