This article is based on analysis published by SolarQuotes
On Christmas day 2025, Australia’s rooftop solar fleet delivered another strong grid performance, driving down wholesale electricity prices and meeting a significant share of national demand during a day of low industrial load and high household consumption.
A growing number of newly installed home batteries also played a role, absorbing excess midday generation and moderating exports – many for the first time over the Christmas period. This highlighted how deeply rooftop solar and household batteries are now embedded in Australia’s energy system.
With ongoing rebates, falling hardware costs and strong consumer demand, distributed energy resources are set to remain a central pillar of the energy transition in 2026 – even as grid integration challenges continue to intensify.
Rooftop solar on Christmas day
Data from OpenElectricity shows rooftop solar supplied 21.5 per cent of total electricity demand across the National Electricity Market (NEM) on 25 December 2025. That energy was exported into the wholesale market at an average negative spot price of –$54.76/megawatt-hour (MWh), reflecting strong midday oversupply.
While marginally lower than the 22.9 per cent share recorded in 2024, rooftop solar still peaked at 50.3 per cent of NEM demand at 1pm AEST.
Across all regions, except the Northern Territory, rooftop solar exports absorbed by the grid totalled 135 gigawatt-hours on the day.
State-by-state performance
Rooftop solar’s contribution varied significantly by region:
- Queensland: 17.6 per cent average; peak 40.7 per cent at 11am AEST
- New South Wales/ACT: 20.4 per cent average; peak 51.4 per cent at 12pm AEST
- Victoria: 25.6 per cent average; peak 64 per cent at 2pm AEST
- South Australia: 43.9 per cent average; peak 107.9 per cent at 12:30pm AEST, exporting more solar than total state demand
- Tasmania: 8.1 per cent average; peak 22.5 per cent at 1pm AEST
- Western Australia: 22.7 per cent average; peak 52.1 per cent at 11:30am AWST
Note: Western Australia is not part of the NEM but is included in OpenElectricity reporting. No comparable data is available for the Northern Territory.
Rooftop solar installations in 2025
Final installation figures for 2025 are still being processed, but early data suggests uptake eased slightly compared with the previous year.
The Clean Energy Regulator reports 221,713 solar systems under 100 kilowatt (kW) were installed by 30 November 2025, compared with 319,044 installations across the full year of 2024. As in previous years, the final total is expected to rise once late registrations are completed.
While installation volumes remain below the 2021 peak of 377,458 systems, average system sizes continue to increase. Residential installations averaged 10.2 kW in the first half of 2025, up from 8.8 kW in 2021, reflecting rising household electricity demand and electrification.
Since 2001, more than 4.26 million rooftop solar systems have been installed across Australia.
Battery uptake accelerates
The standout electrification development of 2025 was the rapid uptake of home batteries following the launch of the Cheaper Home Batteries Program in July 2025.
Between July and 30 November, 125,447 battery systems were installed and registered, with thousands more progressing through the pipeline. In December, Climate Change and Energy Minister Chris Bowen said 163,016 households had installed a battery since 1 July.
Industry estimates suggest up to 175,000 battery systems may have been installed or commissioned since the program’s launch – equating to roughly 3.9 gigawatt-hour (GWh) of usable storage capacity. The Clean Energy Regulator noted this exceeds the combined capacity of the five largest utility-scale batteries currently operating in the NEM.
Average battery sizes have also increased sharply, rising from 10-12 kilowatt-hour (kWh) in 2024 to around 28 kWh by October 2025, driven by higher rebate thresholds and whole-of-home electrification.