Temperature coefficients of degraded crystalline silicon photovoltaic modules at outdoor conditions

Abstract

The temperature effect on photovoltaic modules is usually quantified by means of some coefficients relating the variations of the open‐circuit voltage, of the short‐circuit current, and of the maximum power to temperature changes. In this paper, comprehensive experimental guidelines to estimate the temperature coefficients when measurements are performed outdoors are given. In addition, a correction procedure is applied to the short‐circuit current to cancel out the influence of the fluctuations in the irradiance level. The experimental results shown in this paper refer to several single‐crystalline silicon modules that have been operating for 21 years. Consequently, the estimated values of the temperature coefficients also account for module ageing processes. The coefficients of determination achieved in the case of the temperature coefficients of the open‐circuit voltage and the maximum power are very close to one. Results concerning the temperature coefficients of the short‐circuit current are also suitable if they are previously corrected.

Analysis of the degradation of amorphous silicon‐based modules after 11 years of exposure by means of IEC60891:2021 procedure 3

“…From the results of this comparative, we must conclude, as other authors have stated in the literature, 53 that there is a dependence of the estimated degradation rate on the method of correction used, and this fact requires further study. One possible reason are the high uncertainty associated to the determination of the required parameters to apply some of these methods, 54 In any case, in order to identify the most suitable correction procedure to be used when estimating degradation rates, it is necessary to perform a detailed comparative study among all the several approaches published in the literature, even testing them with modules of different technologies. This can be done using each correcting method to translate an initial measured curve to the conditions of another target curve, also measured, and comparing the corrected curve to the measured target one.…”

“…From the results of this comparative, we must conclude, as other authors have stated in the literature, 53 that there is a dependence of the estimated degradation rate on the method of correction used, and this fact requires further study. One possible reason are the high uncertainty associated to the determination of the required parameters to apply some of these methods, 54 specially if their determination is performed based on outdoor measurements.…”

Analysis of temperature coefficients and their effect on efficiency of solar cell modules for photovoltaics-powered vehicles

“…In order to determine the TC of solar cell modules, the characteristics of solar cell modules are recorded in the range of 25 • C-65 • C, with an interval of 1 K and irradiance of 1000 W cm 2 , according to the IEC60891 [22]. In this paper, the experimental data for TCs of various solar cell modules [16,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] are compared with the calculated results. According to Piliougine et al [23], TCs of Si solar cell modules are shown to be constant in the temperature range between 28 • C and 48 • C. However, the poorer performance Si and Ge solar cells have shown further poorer TCs for open-circuit voltage and fill factor in the higher temperature range above 360 K according to Singh and Ravindra [24].…”

“…In this paper, the experimental data for TCs of various solar cell modules [16,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] are compared with the calculated results. According to Piliougine et al [23], TCs of Si solar cell modules are shown to be constant in the temperature range between 28 • C and 48 • C. However, the poorer performance Si and Ge solar cells have shown further poorer TCs for open-circuit voltage and fill factor in the higher temperature range above 360 K according to Singh and Ravindra [24]. Therefore, vehicles need better performance and better TC solar cell modules on hot days.…”

In situ quantification of temperature and strain within photovoltaic modules through optical sensing

“…However, these techniques lack flexibility and generally have high costs associated 6,7 . From a thermal perspective, thermocouples, resistive‐based temperature detectors (RTDs) or infrared thermography can be used to monitor temperature variations during processing and in the field 8–10 . Incorporating large quantities of these sensors on to or into the laminate can be quite invasive while (dis)continuous outdoor monitoring using thermography can be costly and impractical.…”