Impacts of 2019–20 Australian bushfires on solar photovoltaic generation using high-resolution simulations

As a key component of the clean energy transition, solar photovoltaic (PV) generation is expanding rapidly. Atmospheric aerosols affect solar resources, reducing usable radiation and decreasing PV potential. To investigate the aerosols role on Australian PV potential, the WRF-Solar model is used to simulate the 2019 climate, focusing on the summer bushfire season. Four experiments with different aerosol configurations were conducted, in a 10-km grid spacing domain in continental Australia and a 2-km nested domain over New South Wales. The control experiment (no aerosols) is compared with three experiments that incorporate climatological and time-varying aerosol optical depth (AOD) from the Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA2) and Himawari-8 satellite. The results of the simulated global horizontal irradiance (GHI) and direct normal irradiance (DNI) are evaluated against observations. The resultant PV power potential for each experiment is estimated using a resource-to-power conversion model. During the bushfire season, the inclusion of MERRA2 AOD significantly improved the simulation of solar irradiance, especially the DNI, compared to ground stations (up to 83% bias improvement) and satellite-derived irradiance (up to 18% improvement in the root mean square deviation). The inclusion of Himawari-8 AOD data is also beneficial, but its spatio-temporal coverage is highly limited due to the large number of gaps from cloudy pixels. Reductions of up to 16% in the PV power potential were evident in the experiment including MERRA2 3-hourly AOD compared to the control experiment, demonstrating the importance of including time-varying aerosols when simulating the PV energy production.