Hmm… one of the key arguments made by the LNP and their supporters is the need for coal (and, to a lesser extent, gas) power stations to provide reliability. Even their nod at a renewables option – the Snowy 2.0 project – is about providing reliable baseline power.
So what does the Australian Energy Market Operator say? “Extreme weather over summer could reduce the output of COAL, GAS and HYDRO power generators and cause problems with the reliability of electricity supply”
Coal, in particular, doesn’t work well when the weather gets hot. They need to be cooled, nearly always by water. When that water gets warm, it doesn’t cool as well, and the coal-based power systems start to shut down. Gas turbines have similar problems – not as severe, but they exist. Hydro’s problem is that drought reduces the size of water reservoirs, which means that there may not even be available water to run through the generators. This isn’t a big deal for stored-power hydro stations (which refill their reservoirs), but is a big problem for regular hydro plants.
Fun fact: the major power disruptions over the last few years have been because of failures with either coal or gas stations, or due to disruptions in the network. The adoption of solar, in particular, can be credited for preventing daytime power disruptions.