Western Australia's rooftop solar now state's 'biggest power station'

Data published this week by Curtin University in Australia has revealed that the sheer volume of rooftop solar capacity installed in the state of Western Australia (WA) is such that, collectively, solar power comprises the state’s de facto largest power station.

Figures published by the Australian Clean Energy Regulatory late last year show that WA has more than 192,000 solar power systems installed, and research from Curtin University shows that there is 500 MW of PV capacity connected to the state’s South West Interconnected System (SWIS).

In 2015, some 1,750 new residential solar installations were added to the SWIS each month, with rooftop solar now installed on 20% of all homes in WA. According to Curtin University sustainability professor Peter Newman, that figure could grow to 50% by 2020.

Newman said that WA’s utilities have been caught napping when it comes to solar’s surge, and have tied themselves into coal and gas contracts for 20 to 30 years while also trying to figure out what to do with a previously mothballed but modernized – yet rarely switched on – old power stations, Muja A and B.

As things stand, WA’s electricity network is some 66% over capacity, partly due to solar’s growth but also because of the utilities’ shortsightedness. Curtin University energy lecturer professor Philip Jennings told the Guardian Australia that WA has "effectively built another very large power station on the rooftops of Perth", which has served to throw the government’s calculations out of whack.

Jennings added that utilities would be keen offload their old power stations, but stressed: "At the present situation I don’t think anyone would take them even if they gave them away for nothing." The energy profile of WA has changed to such an extent that privatization of energy assets is becoming the least attractive option.

"Every time they put up the tariff for coal-fired power in WA, it just encourages people to put solar on their rooftops," said Jennings. "The general take-up rates are not in the wealthy suburbs [of Perth]; they are in the mortgage belt. People factor solar into the cost of building a house."