Does solar work in a blackout?
Most people assume panels on the roof mean power in a blackout. For most homes they don't. Here is why, and what it takes to keep the lights on.
The short answer
- Solar on its own: usually switches off in a blackout, to protect people working on the grid.
- A battery: can keep power on, but only if it is set up for backup. Not every system is.
- Ask first: whole-house or selected circuits, and whether solar can recharge the battery during an outage.
Why solar switches off
When the grid goes down, a grid-connected inverter shuts down, so the system makes no power[1][2]. It is a safety feature: it stops your panels feeding power into lines someone may be repairing. Very few solar-only systems give backup power[2].
What a battery changes
A battery can supply power in an outage, but only if it is configured to, and not every battery system can[2].
- Basic backup: the battery runs the house until it is empty, then nothing until the grid returns[2].
- Islanding system: disconnects from the grid and lets the panels recharge the battery by day. It costs more, but with care can last several days[2].
- Whole house or essentials: backup can cover the whole home or just chosen circuits, such as lights, the fridge or a water pump[2].
Is backup worth paying for?
If you live where outages are common, tell your installer you need backup at the start[3]. If outages are rare, backup is a nice extra, not a reason to buy a battery. The saving on your bill is what pays for it.
What to ask the installer
- Will this system power the house in a blackout, and which circuits?
- Can the panels recharge the battery during a long outage?
- How quickly does it switch over, and is there an extra cost for the backup hardware?
- Will heavy loads like ducted air conditioning run on backup?
Why two quotes for the same job can be thousands apart
Installers price the same system very differently. These are the installed price ranges our calculator works from, before rebates: the low end is what a competitive installer charges, and the high end is what a poor quote looks like.
| System | Competitive quote | Poor quote |
|---|---|---|
| 6.6kW solar system | $8,000 | $10,000 |
| 10kWh battery | $7,650 | $13,500 |
| About 15kWh battery | $12,100 | $18,000 |
- The gap usually comes from margin, the brand of panel, inverter or battery, and extras such as a switchboard upgrade or backup circuit, not from a better install.
- Get at least two or three quotes, and ask for each to be itemised: hardware brands and models, size, rebates taken off, and anything extra.
- Compare batteries on price per usable kWh, not the headline price.
Get the numbers for your own home
Two minutes of questions about your bill, roof and routine gives you the system size, what it should cost after rebates and what it saves. Your report shows on screen straight away, and no installer sees anything unless you ask.
Run my numbers, freeCommon questions
Will my solar panels work during a power outage?
Usually not. A grid-connected inverter shuts down when the grid goes down, so the system makes no power.
Does a battery give me backup power?
Only if it is set up for it. Some batteries can't, and backup may cover only selected circuits.
Can I run my whole house on a battery in a blackout?
Some systems can, but many cover only essential circuits. Ask before you buy.
Sources
- Clean Energy Council, Guide to installing solar PV. Read 4 November 2026.
- energy.gov.au (Australian Government), Batteries. Read 4 November 2026.
- energy.gov.au (Australian Government), Design considerations. Read 4 November 2026.