Estimation of future changes in photovoltaic potential in Australia due to climate change.

Solar photovoltaic (PV) energy is one of the fastest growing renewable energy sources globally. However, the dependency of PV generation on climatological factors such as the intensity of radiation, temperature, wind speed, cloud cover, etc can impact future power generation capacity. Considering the future large-scale deployment of PV systems, accurate climate information is essential for PV site selection, stable grid regulation, planning and energy output projections. In this study, the long-term changes in the future PV potential are estimated over Australia using regional climate projections for the near-future (2020–2039) and far-future (2060–2079) periods under a high emission scenario that projects 3.4 ◦C warming by 2100. The effects of projected changes in shortwave downwelling radiation, temperature and wind speed on the future performance of PV systems over Australia is also examined. Results indicate decline in the future PV potential over most of the continent due to reduced insolation and increased temperature. Northern coastal Australia experiences negligible increase in PV potential during the far future period due to increase in radiation and wind speed in that region. On further investigation, we find that the cell temperatures are projected to increase in the future under a high emission scenario ◦(2.5 C by 2079), resulting in increased degradation and risks of failure. The elevated cell temperatures significantly contribute to cell efficiency losses, that are expected to increase in the future (6–13 d yr−1 for multi-crystalline silicon cells) mostly around Western and central Australia indicating further reductions in PV power generation. Therefore, long-term PV power projections can help understand the variations in future power generation and identify regions where PV systems will be highly susceptible to losses in Australia.

Figure 4. Historical and projected changes in the cell temperature and number of days beyond 15% relative cell efficiency losses over Australia. Panel (a) represents the mean daily maximum cell temperature over Australia for the historical period (1990–2009). Panels (b) and (c) represent the relative change in the mean daily maximum cell temperature for the near future period (2020–2039) and the far future period (2060–2079) obtained with respect to the historical period (1990–2009). Panel (d) represents the maximum cell temperature for the historical period (1990–2009). Panels (e) and (f) represent the relative change in the maximum cell temperature for the near future period (2020–2039) and the far future period (2060–2079) obtained with respect to the historical period (1990–2009). Panel (g) represents the climatological total number of days/year cell temperature exceeds the threshold temperature for minimum 15% reduction in relative cell efficiency for the historical period (1990–2009). Panels (h) and (i) represents the relative change in number of days/year the cell temperature exceeds the threshold temperature for minimum 15% reduction in relative cell efficiency for the near future period (2020–2039) and the far future period (2060–2079) obtained with respect to the historical period. Stippling indicates a significant change (according to section 2.4).