BNEF said Australia had one of the world's lowest levelised cost of electricity for onshore wind and solar.

The Australian National University forecast future prices of new renewable energy generators would fall to $50 a megawatt hour in the 2020s.

The ASX forward prices for NSW between the 2020 March quarter and 2021 December quarter run to an average of $75.73 a megawatt hour for coal-fired power.

Globally, the levelised cost of electricity for wind farms was $US55 per megawatt hour for the first half of 2018, down 18 per cent from the same time last year, while solar power has also fallen 18 per cent to $US70 per megawatt hour. Only offshore wind generation failed to fall significantly, dipping 5 per cent in costs year on year

EY believes Australian renewable energy will cost the same or be cheaper than fossil fuels as soon as 2020.