Outdoor comparison of rooftop grid-connected photovoltaic technologies in Marrakech (Morocco)

For the first time in Morocco after 32 month of outdoor measurements, the comparison of performance of three grid-connected silicon-based PV technologies is presented. The three PVGCS have similar nominal rated powers and use the same inverter and this work shows that under such conditions, the comparison can be made indifferently on the basis of AC yields or on the basis of DC performance ratios. Our results show that in Marrakech, in winter, pc-Si (polycrystalline) yields achieve 11% more than a-Si/µc-Si (amorphous on microcrystalline) but it generates 7% less than mc-Si (monocrystalline). In summer, pc-Si yields perform 4% less than a-Si/µc-Si, but 7% more than mc-Si. Relative performance of a-Si/µc-Si increases by nearly 0.6% per °C against its two other bulk-silicon competitors, supporting that a-Si/µc-Si cells operate with a positive temperature power coefficient. Analysis of the daily data show that: (i) a-Si/µc-Si cells daily performance degrade 1.1% faster that mc-Si, (ii) a-Si/µc-Si cells daily performance degrade 0.2% faster that pc-Si, (iii) pc-Si cells daily performance degrade 0.9% faster that mc-Si. Cumulative yearly PV yields show that: (i) a-Si/µc-Si solar cells AC yearly yield performs around 1.5% more than the mc-Si one but degrades yearly nearly 1.5% faster than the former, (ii) that a-Si/µc-Si solar cells AC yearly yield performs around 2.2% less than the pc-Si ones and degrades yearly nearly 0.8% faster than the former, (iii) pc-Si solar cells AC yearly yield performs around 3.8% more than the mc-Si ones but degrades yearly nearly 0.8% faster than the former. The use of relative PV yields will be extended for other Moroccan sites for which have the same data without solar radiation measurements.