Building photovoltaic (PV) technologies have been widespread developed. However, the quantitative impact of PV panels on both urban climate and energy balance needs to be investigated. This study adopts the Weather Research and Forecasting model to discuss coupling effects of rooftop PV panels on thermal climate and electricity balance for cooling, and provides installation strategies accordingly. Numerical simulations with five rooftop PV coverage fractions of solar panels for a clear-sky are conducted at a high spatial resolution. Results indicate that rooftop PV panels cool Singapore by a maximum of 1.0 °C during the daytime, and no impact on nocturnal air temperature is observed. PV coverage fractions of 75%–100 % and 75 % are recommended for the North-East area and other four areas to decrease air temperature at least 0.8 °C and 0.4 °C respectively. The electricity offset percentages (EOP) are linearly related to rooftop PV coverage fractions. To maximize the cooling energy offset, 75 % PV coverage is sufficient for most regions of Singapore, while 100 % is recommended for the West and East. By leveraging the dual effects on city cooling and energy balancing, East/West/North-East regions follow the principle of a rooftop PV coverage fraction of 100 %, while 75 % is suggested in the Central/North areas.
Read full abstract