Safe grounding system design for a photovoltaic power station

A safe and cost-efficient grounding system design of a 3 MWp photovoltaic power station according to IEEE Std 80-2000 is presented. Grounding analysis is performed by considering the metal parts of the photovoltaic panel arrays foundations as auxiliary ground electrodes. Utilizing also horizontal ground conductors, required solely for the interconnections of the metal support structures of the photovoltaic panel arrays, both safety and cost-efficiency in grounding system design have been achieved. It is shown that in large-scale photovoltaic power stations where the metal parts of the panel arrays foundations are concrete encased the concrete resistivity is not an important parameter in evaluating the safety performance of the grounding system.