ROOFTOP solar panels could power South Australia’s entire electricity grid during minimum demand times within a decade, posing possible issues for the stability of the system.

A report from the Australian Energy Market Operator (AEMO), to be released today, estimates that by 2023-24, “demand” from the grid for electricity from traditional energy generators could fall to zero at times.

Minimum demand time refers to the lowest point during a minimum demand day.

This could have serious implications for the long-term maintenance of and investment in the power grid and power generation in SA, which has the highest penetration of rooftop solar in the nation.

AEMO managing director Matt Zema said his agency would be looking into what the forecast meant for system security and reliability.

“By the summer of 2023-24, rooftop photo voltaic (PV) generation could be sufficient to meet all demand in that region, at the minimum demand time,” Mr Zema said.

“These observations from the 2015 National Electricity Forecasting Report (NEFR) reflect both the changing generation mix, and increasing consumer engagement when it comes to choice and energy supply solutions.

“The level of generation from wind and rooftop PV technologies is significant in areas of the network and will continue to grow to meet the Renewable Energy Target.

“The challenge for the industry is how to integrate these renewable energy sources into the grid, while maintaining the levels of reliability and power quality which consumers expect.”

Mr Zema said that these challenges were not unique to Australia and similar issues were being played out in other markets around the world.

From now until 2017-18, the power output of residential rooftop solar in SA is expected to increase by a third, from 753 gigawatt hours to 1005, and commercial solar is expected to more than double, from 109 to 284.

This is despite previously generous State Government feed-in tariffs being phased out.

In 2013-14 rooftop solar accounted for 5.9 per cent of South Australia’s energy generation, with 45.5 per cent gas, 31.2 per cent wind and 17.3 per cent coal. Alinta Energy announced last week it would shut down its coal fired power stations at Port Augusta by March 2018.

The AEMO report showed that on SA’s lowest demand day last year — Boxing Day at 1.30pm to be precise — rooftop solar was sufficient to supply 36 per cent of grid demand.