Australia’s coal dependent electricity grid will lose 60 per cent of its coal plants over the next eight years, requiring urgent investment in renewables and batteries, the country’s energy market operator has warned.

The Australian Energy Market Operator also said A$12.8bn ($8.8bn) must be urgently spent on new transmission lines to accommodate a rapid increase in renewables. In total, AEMO expects around A$320bn of investment will be needed to upgrade and operate a low carbon grid by 2050.

Australia’s main grid is dominated by coal power, which supplies around 60 per cent of the eastern states’ electricity. But the shift to renewables has been rapid, driven largely by households installing solar panels on their roofs.

The lack of a national energy policy under the previous pro-coal conservative government has deterred investment and led to warnings of an unstoppable but disorderly transition to a renewables-dominated grid.

Power companies have already said they plan to withdraw 8 gigawatts of coal-fired capacity by 2030. But AEMO now expects other coal closures will be brought forward, and 14 gigawatts of coal capacity will be withdrawn by 2030.

“To maintain a secure, reliable and affordable electricity supply for consumers through this transition to 2050, investment is required for a nine-fold increase in grid-scale wind and solar capacity, triple the firming capacity (dispatchable storage, hydro and gas-fired generation) and a near five-fold increase in distributed solar,” AEMO chief executive Daniel Westerman said in a statement.

AEMO now expects more than 80 per cent of the main grid’s electricity to come from renewables by 2030.