Sensitivity analysis of the carbon payback time for a Brazilian photovoltaic power plant

Abstract Decreasing upfront costs, governmental policies, and promises to reduce greenhouse gas emissions have provoked a sharp increase in the installed capacity of photovoltaic (PV) plants worldwide. In Brazil, PV plant installation has been growing since 2014, stimulated by the Ministry of Energy and Mines auctions dedicated to this technology. Net emissions vary depending on the emissions from the grid where PV plants are installed, and little is known about their actual payback times in tropical areas. This study calculates the carbon payback time of a 3.0 MWp PV power plant with a sensitivity analysis. We conclude that the PV plants installed in northeast Brazil are beneficial to climate change mitigation whether the PV module is mono-Si or poly-Si, manufactured abroad or not and, considering uncertainties about emissions from alternative technologies, especially hydropower.