Data on the sources of power in the National Electricity Market showed that at 11.50am on Wednesday, renewables were providing 50.2% of the power to Queensland, New South Wales, Victoria, Tasmania and South Australia – the five states served by the market.

Rooftop solar was providing 23.7% of all the power demand, followed by wind at 15.7%, large-scale solar with 8.8% and hydro at 1.9%.

At the same time, coal was still the largest provider of electricity on the grid, with power stations fed with black coal generating 35.7% and brown coal plants at 13.5%.

First reported on RenewEconomy, the milestone was spotted using an online tool called OpenNEM that monitors the grid in real-time using data from the Australian Energy Market Operator.

Dylan McConnell, of the University of Melbourne’s Climate and Energy College and who helped develop the tool, said: “We will start to see this happening more frequently. It was just a snapshot in time, but it’s indicative of an underlying trend in the system.”

Renewables maintained the 50% mark for only about 10 minutes and over the entire day contributed 31.2% of the electricity used across the five states.

McConnell said spring months have generally been times of high renewables output, when demand was not being driven either by customers wanting to heat or cool homes.

A continuous rollout of rooftop solar electricity was a key driver, McConnell said.

The milestone reflects a rapid acceleration on renewable energy deployment across Australia in recent years that has seen record-breaking levels of investment.

In 2018, a report from the Clean Energy Regulator has shown more than 2m small solar systems were installed, next to 3.5 gigawatts of large renewables projects accredited against Australia’s 2020 renewable energy target.

The report said Australia was now ahead of schedule in meeting the large-scale target of 33,000 gigawatt hours of renewables generation by 2020.

Other analysts say that clean energy could make-up 35% of Australia’s electricity needs within two years.

Kane Thornton, chief executive of the renewable energy industry’s Clean Energy Council, said: “It is a fantastic achievement to have more than half of the National Electricity Market powered by renewable energy, and it’s worth celebrating.

“A decade from now it will be completely normal as more renewable energy and storage projects are built to replace retiring coal-fired power stations.

“At the beginning of the decade South Australia’s power system ran on more than 50 percent wind and solar for the first time, but today it happens all the time.

“Renewables and storage can do everything our old coal plants can do, just cheaper, cleaner and more reliably.”