Australia's solar farms are switching off far less often at times of negative prices, as a rapid build-out of large and home batteries soaks up surplus midday power. According to the Australian Energy Market Operator's (AEMO) Quarterly Energy Dynamics report for the September quarter, analysed by RenewEconomy, solar economic offloading fell by 54% year on year.
Fewer shutdowns at midday
Economic offloading happens when solar and wind farms turn down their output because prices have fallen too far below zero. In the third quarter of 2026, solar offloading fell by an average of 177 MW compared with a year earlier. As a share of average solar availability, it dropped from more than 16% to 5.9%.
The biggest change came in Queensland, where solar offloading fell by 63%, or 139 MW, to an average of 81 MW. New South Wales recorded a 61% fall and South Australia 24%. Victoria was the exception, with a 52% rise.
AEMO said: "This reduction reflected higher grid-scale battery charging and increased daytime operational demand."
Batteries overtake gas
The same report shows how quickly storage is changing the National Electricity Market. Grid-scale batteries supplied 8% of total generation in the quarter, more than gas-fired generation at 5.1%, for the first time in any quarter. On average, batteries charged 13.4 GWh a day during daylight hours and discharged 10.9 GWh into the evening peak.
"Increased battery charging and discharging contributed to significantly lower evening peak prices," said Violette Mouchaileh, AEMO Executive General Manager Policy and Corporate Affairs, with batteries setting prices in almost half of dispatch intervals, up from 18% a year earlier.
Standalone grid-scale battery capacity has tripled in a year. Home battery installations have also surged with the help of a federal rebate, and most new solar farms are now being built with co-located batteries.
Solar keeps growing
Grid-scale solar averaged 2,211 MW in the quarter, up 30% on a year earlier, and reached an all-time peak of 8,290 MW on August 27. Rooftop solar capacity across the market reached about 27 GW from 3.9 million installations, up 12% year on year.
The grid is the new bottleneck
Not every measure improved. Network curtailment, which happens when output is limited by grid constraints, faults or security issues, doubled to a record average of 281 MW for wind and solar combined. Grid-scale solar curtailment nearly tripled to 169 MW, or 6.7% of solar availability, with southern New South Wales most affected.
What it means
For Asia-Pacific markets, Australia offers a clear lesson: batteries are the fastest way to turn surplus midday solar into revenue and lower evening prices. They have cut market-driven shutdowns of solar farms by more than half in a single year. But as price-driven losses fall, grid-driven losses are rising, so transmission capacity is now the main risk for solar developers. New projects that pair solar with storage and secure strong grid connections will be best placed.
Source: RenewEconomy and pv magazine, based on AEMO's Quarterly Energy Dynamics report for Q3 2026.
