Can rooftop solar panels cover increased electricity loads during heatwaves?

With climate change, it is expected that frequency and intensity of extreme weather events will increase. An example of extreme weather event is heat waves, which are defined as three or more consecutive days of unusually high temperatures. These long periods of hot weather have serious effects on health and have caused many mortalities in the past. To better cope with such weather conditions, many people have installed air-conditioners. However, when many such cooling appliances are all switched on at the same time and industry is operating, the electricity demand peaks, often leading to great stress on the network. Understanding the impact of heatwaves on the health of the electricity network is therefore important, especially as these types of events are expected to increase. We have analysed the impact of heatwave on electricity consumption in Queensland, and investigated rooftop solar panels as an option to reduce peak demand during such weather events. Two analyses were undertaken for the February 2017 heatwave for two levels of details: a global analysis at the state level and a detailed analysis on a low voltage network. The first study compares the electricity demand for the whole state of New South Wales during the heatwave event and quantifies the contribution of solar panels output in reducing electricity demand. It showed that the peak consumption was reduced by about 4% (where PV generated 597 MW over half an hour) thanks to the rooftop solar panels contribution. The second study focusses on the consumption of nine individual premises located in a same street in Townsville. The contribution of the solar panels in reducing the households’ demand from the grid varied quite significantly amongst the different users, from 0.6% to 25%, with a median of 3.5%. While the first study gives an estimate of how much solar panels can help reduce the demand on the state overall, the second one which is location specific takes into account the network constraints in terms of consumption and production of electricity. This location-specific study highlights the importance of understanding where, when and how electricity is consumed and produced. It provides a better estimate when considering solar panels to alleviate the impact of extreme weather events which can be used when planning the network