Will my solar panels work during a blackout?
Most standard grid-connected rooftop solar systems shut down during an outage. This safety feature, known as anti-islanding, stops power being sent into the network while crews may be repairing it. Solar panels alone generally won’t keep your home running in a blackout, though some specially configured systems can run independently of the grid.
Does a home battery automatically provide blackout backup?
No. A home battery is often installed mainly to store solar and cut your bills. For blackout protection it also needs compatible inverter and switching equipment, correct isolation from the network and a backup configuration that’s switched on. Some systems back up only selected circuits; others support more of the house. Ask your installer to put the supported circuits, switchover behaviour and any limits in writing.
Essential circuits or whole-home backup?
Essential-circuit backup covers things like the fridge, lights, internet router and a few power outlets. It usually needs less power than running a whole house. Whole-home backup may need higher battery output, more stored energy and a more complex electrical design. If your home has three-phase power, confirm which phases and circuits will stay live during an outage.
Can a battery run air conditioning during a heatwave?
Possibly, but it depends on the air conditioner’s demand, the battery’s usable energy, its backup power output and the circuits wired for backup. Cooling can use a lot of energy and may sharply cut battery runtime. Appliances can also draw extra power when they start up. Never assume a battery can run cooling just because its storage number looks big.
How long could a 10 kWh battery last?
Battery capacity is measured in kilowatt-hours (kWh). The power it can deliver at once is measured in kilowatts (kW). Runtime depends on the charge available, reserve settings, conversion losses and the combined power demand of the appliances you run.
Illustrative example: A 10 kWh battery with 90% charge, 10% reserved charge, 95% usable-capacity assumption and 90% system conversion efficiency provides about 6.8 kWh of modelled energy. At an average 200 W essential load, that would last roughly 34 hours with no solar recharge. At 1,400 W, it would last under five hours. Actual results can differ substantially.
Try the EnergyBrain battery backup calculator
Select a battery and the appliances you want to keep running. See an illustrative backup runtime estimate, assuming your system is properly configured for backup and no solar recharging during the outage.
1. Your battery
2. What stays on?
How this works: available AC energy = nominal capacity × usable-capacity factor × (starting charge − reserve) × 90% assumed discharge/conversion efficiency. Estimated hours = available AC energy ÷ selected average appliance load. The appliance wattages are illustrative averages, not a prediction of your exact devices. Solar generation during the blackout is excluded, making this a battery-only model.
Can solar recharge the battery during an outage?
Only if the solar-and-battery system is set up to run independently of the grid and allows solar generation during a blackout. Some backup systems run on battery energy alone until grid power returns. Others can keep generating and charging in decent sunlight. Ask your installer which one you’d get, and whether it works when the battery is nearly empty.
What about storms, bushfires and multi-day outages?
Backup planning matters most for properties hit by storms, bushfires, remote network faults and long summer outages. Think about which appliances your household truly needs, the chance of cloudy days and the minimum reserve you want to keep. A battery is not a substitute for a personal emergency plan. Follow your state emergency service advice during heatwaves or severe weather.
Seven questions to ask your solar installer
- Will the system provide backup during a blackout, and is that included in the written quote?
- Which rooms, power outlets and circuits will operate, including on a three-phase property?
- What is the continuous backup output in kW, and can it handle appliance startup loads?
- What usable battery capacity and minimum reserve will be available during an outage?
- Will solar panels continue generating and recharging the battery while the grid is down?
- What happens when the battery is depleted, and how does the system restart?
- How do battery settings or a virtual power plant affect the energy reserved for blackout backup?
Frequently asked questions
Can I add blackout backup to an existing solar system?
Sometimes. It depends on your existing inverter, battery compatibility, electrical setup and any network requirements. A qualified installer should check the equipment before quoting.
Does a battery still help if it cannot provide backup?
Yes. It may store excess solar for the evening and reduce the electricity you buy from the grid, even without blackout functionality. Whether it’s cost-effective depends on your usage and tariffs.
Should I back up my whole house?
Not necessarily. Backing up a few essential circuits can lower the system cost and stretch the runtime. Think about any medical, cooling, water pumping or communications needs before you choose.
Do government battery incentives guarantee blackout protection?
No. Incentives and technical backup functionality are separate questions. Confirm whether the proposed battery is eligible for the relevant scheme and whether blackout operation is included in your design.
Can a virtual power plant affect my blackout reserve?
It can. Some virtual power plant arrangements may change how a battery charges and discharges. Ask about the minimum charge reserve and what happens ahead of a forecast storm.
Start with your roof
A suitable roof is the first step towards a solar-and-battery plan. Explore yours with Emily, then talk to an accredited professional about battery sizing, backup configuration and installation costs. No pressure. EnergyBrain produces modelled estimates, not confirmed battery designs or guaranteed backup durations.
Related EnergyBrain guide
Am I eligible for free or subsidised solar panels in Australia? Learn about federal solar incentives and battery discounts before you compare quotes.
Keep reading
Official Australian sources
Last reviewed: 9 October 2026. This is general educational information. Backup capability depends on your particular battery, inverter, wiring, settings and solar conditions. Appliance loads and runtime estimates are indicative only. Use a qualified installer for system design and follow official emergency advice.