During the recent heatwave that hit much of Australia, air conditioning systems were hard at work – and rooftop solar power systems played their part in reducing the strain on the power grid while making air conditioning greener and more cost-effective to use.
How much electricity was provided by rooftop solar panels?
From approximately 4:30am last Monday, January 5, 2026, to the same time this morning (January 12), rooftop solar contributed 18.8% of total electricity demand in the National Electricity Market (NEM – QLD, NSW/ACT, VIC, SA and TAS) and Western Australia’s South-West Interconnected System (SWIS). Utility-scale solar increased another 10.3%.
The maximum contribution of rooftop solar systems installed in NEM regions was 46.9% at 12 noon on Monday, January 5, followed by 45.9% at midday on Wednesday, January 6. Overall, all renewable energies covered 49.9% of demand in the reporting period.
Here’s what happened in every state and territory over that period (except NT – I don’t have the numbers), based on data from Open Electricity:
Queensland:
- Demand coverage through solar roofs: 14.7%
- Solar power consumed: 226 gigawatt hours (GWh)
- Maximum contribution: 37.9% (January 6, 12 p.m.)
- Total share of renewable energy: 41.6%
New South Wales/ACT
- Demand coverage through solar roofs: 16.4%
- Solar power consumed: 290 GWh
- Maximum contribution: 47.1% (January 6, 12:30 p.m.)
- Total share of renewable energy: 44.7%
Victoria
- Demand coverage through solar roofs: 16%
- Solar power consumed: 202 GWh
- Maximum contribution: 59.4% (January 5, 12 p.m.)
- Total share of renewable energy: 51.3%
Tasmania:
- Demand coverage through solar roofs: 7.0%
- Solar power consumed: 13.5 GWh
- Maximum contribution: 23.6% (January 5, 11:30 a.m.)
- Total share of renewable energy: 89.4%
South Australia:
- Demand coverage through solar roofs: 66.6%
- Solar power consumed: 1,510 GWh
- Maximum contribution: 81.4% (January 10, 2:30 p.m.)
- Total share of renewable energy: 94.7%
Note: I originally recorded the numbers yesterday, and when I checked them again on Open Electricity this morning, they were actually off (much lower) for South Australia. Therefore, I decided to use the originally recorded numbers from January 4th to 11th as they seemed to more closely match what was happening when I checked SA from time to time during that period. I will check the numbers again in the coming days and adjust them if necessary.
Western Australia
- Demand coverage through solar roofs: 27.6%
- Solar power consumed: 130 GWh
- Maximum contribution: 60.7% (January 9, 1:30 p.m.)
- Total share of renewable energy: 52.5%
In a graphic:
New record for electricity demand set
During this period, underlying NEM demand temporarily rose to a record high of more than 40,000 megawatts, and from January 7th to 9th, the NEM saw the highest electricity demand in the period from January 5th to 12th.
Hot summer days pose a challenge to power grids and cause anxiety among grid operators as high temperatures drive increased use of air conditioning.
However, Global Power Energy’s Geoff Eldridge said that, thanks in part to the installation of rooftop solar panels, there had been no reports of missing reserves and no calls for emergency reserves, and that prices had remained largely stable through the middle of the day. At times wholesale spot prices were even negative, which is becoming more and more common.
“Summit [underlying] “Demand is higher than in 2019 and summer heat remains a key challenge,” he said. “What has changed is the way the system addresses this challenge.” Solar energy now carries much of the heat-related load during the day.”
The remaining challenge in summer is in the evening hours when the solar panels no longer produce electricity. But even this will be less of a problem in the coming years thanks to the Cheaper Home Batteries Program (CHBP). Since the program officially launched in July 2025, more than 175,000 home batteries have been installed. These batteries will serve their owners well, helping to power their homes during evening peak hours and driving down wholesale electricity prices – benefiting everyone.
The week would also have been a good test of how home batteries cope with extreme heat.
In addition to residential solar batteries, numerous utility-scale energy storage projects are also being built – currently there seem to be project announcements every other day.
Virtual power plants still shine
Another key element in taming the electricity system is virtual power plants (VPPs). These are networks of distributed energy resources such as home batteries and solar panels, controlled centrally by a third party, and intelligent software that acts as a single power source, balancing the grid and reducing peak demand.
But virtual power plants have not yet had a real breakthrough in Australia; even though we supposedly lead the world. Battery owners are still wary and concerned about various issues, such as how hard a VPP operator might hit a battery and the impact this may have on not only the battery warranty but also longevity.
According to this report from the Australian Competition and Consumer Commission (ACCC), around 38,200 Australian households were participating in VPPs as of January last year, with uptake increasing by almost 22% every six months over the last two and a half years.
However, participation is still far behind single battery systems. While there is a requirement under the CHBP that installed solar batteries be VPP capable, participation in a program is not required. However, additional incentives can be created for this. For example, in New South Wales and South Australia a charge for connecting batteries to a VPP is available.
You can compare what’s available across Australia on SolarQuotes’ VPP comparison page.
By the way, you can also read here how the roof solar system performed on Christmas Day 2025.
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