Estimation of rooftop solar photovoltaic potential of a city

Abstract

A methodology for estimating the rooftop solar photovoltaic potential for a region has been described. The methodology has been applied and illustrated for the Indian city of Mumbai (18.98°N, 72.83°E). It uses high-granularity land use data available in the public domain and GIS-based image analysis of sample satellite images to estimate values of the Building Footprint Area (BFA) Ratio. Photovoltaic-Available Roof Area (PVA) Ratio has been estimated by simulations in PVSyst and has been compared with relevant values from the literature. Solar irradiance (DNI and DHI) and ambient temperature data have been taken from Climate Design Data 2009 ASHRAE Handbook. Liu Jordan transposition model has been used for estimating the plane-of-array insolation. Effect of tilt angle on the plane-of-array insolation received has been studied to make an optimum choice for the tilt angle. Micro-level simulations in PVSyst have been used to estimate effective sunshine hours for the region of interest. The installed capacity, annual and daily generation profiles and capacity factor have been estimated for PV panels with different rated solar cell efficiency and power–temperature coefficient values.The results show a potential of 2190MW for Mumbai city with median efficiency panels, at an annual average capacity factor of 14.8%. Daily and monthly variation of the generation from the Rooftop PV Systems has been studied. Comparison with sample daily load profiles shows that large scale deployment of Rooftop Solar Photovoltaic Systems can provide 12.8–20% of the average daily demand and 31–60% of the morning peak demand for different months, even with median conversion efficiency panels. This method can be used to obtain the PV potential for any region.