South Australia’s rooftop solar systems met 99.9 percent of the state’s total electricity demand at 1:30 p.m. on August 31, the Australian Energy Market Operator said.
The burst of daytime generation reduced operational demand from the grid to just two megawatts. It also helped set a new winter minimum for operational demand across Australia’s National Electricity Market.
Batteries were charging as the sun produced more power than the grid needed at that moment. Battery charging accounted for about 10.5 percent of total generation across the market, while wholesale prices were negative in every region.
The milestone also shows why a renewable-powered grid needs flexible storage and transmission. South Australia is learning how to balance a growing supply of electricity from homes, businesses and larger renewable projects.
