Modeling and Simulation of the Influence of Interconnection Losses on Module Temperature in Moderate and Desert Regions

Photovoltaic (PV) modules in desert environments benefit from higher irradiation levels and, therefore, better energy yield. However, higher irradiation leads to higher temperature and higher electrical losses in module interconnections, which could influence the lifetime and energy yield of PV modules. The electrical losses in module interconnection act as heat sources. The interconnections' electrical properties are also affected by solar cell temperature. In this paper, we simulate and evaluate the performance of the interaction between thermal and electrical losses in module interconnections and the influence of tab on module power and temperature. We compare the impact of tab losses on module power and temperature under different irradiation and ambient temperature levels, as well as compare the module in Qatar and Germany as desert and moderate climates. We show that the thermal influence of tab on module power is maximum 0.8%
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compared to a module without any thermal influence from tab, which, in this case, are the thermal coefficients of the tab and temperate elevation due to joule heating. This change is 0.2%
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and 0.6%
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for Qatar and Germany during one year, respectively. As a solution for desert applications, apart from full-cell layout, we have evaluated modules with half-cell design due to increased optical gains and reduced electrical losses. We determined the optimum tab width for the modules with half-cell and full-cell design and for two to five busbars under normal operating cell temperature (NOCT) conditions. We show that in NOCT conditions, the optimized tab width on half-cell modules is almost half of the tab width for full-cell modules. Furthermore, the temperature of half-cell modules is always less than that of full-cell modules for the similar tab widths. By considering the optimum tab width for half-cell and full-cell modules, an average increase of 0.2 °C is simulated, which is due to the higher active area and narrower tabs and, thus, higher irradiance and thermal loads.