The Energy and Environmental Performance of Ground-Mounted Photovoltaic Systems—A Timely Update

Given photovoltaics’ (PVs) constant improvements in terms of material usage and energy efficiency, this paper provides a timely update on their life-cycle energy and environmental performance. Single-crystalline Si (sc-Si), multi-crystalline Si (mc-Si), cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS) systems are analysed, considering the actual country of production and adapting the input electricity mix accordingly. Energy pay-back time ( EPBT ) results for fixed-tilt ground mounted installations range from 0.5 years for CdTe PV at high-irradiation (2300 kWh/(m 2 ·yr)) to 2.8 years for sc-Si PV at low-irradiation (1000 kWh/(m 2 ·yr)), with corresponding quality-adjusted energy return on investment ( EROI PE -eq ) values ranging from over 60 to ~10. Global warming potential (GWP) per kWh el averages out at ~30 g(CO 2 -eq), with lower values (down to ~10 g) for CdTe PV at high irradiation, and up to ~80 g for Chinese sc-Si PV at low irradiation. In general, results point to CdTe PV as the best performing technology from an environmental life-cycle perspective, also showing a remarkable improvement for current production modules in comparison with previous generations. Finally, we determined that one-axis tracking installations can improve the environmental profile of PV systems by approximately 10% for most impact metrics.

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