This one surprises a lot of people. You've got solar panels on your roof. The sun is shining. The power goes out. And your house goes dark.
That's not a fault. It's the system working exactly as it should — for everyone except you.
Why Solar Shuts Off in a Blackout
Almost all Australian home solar systems are grid-connected. When the grid goes down, your inverter automatically shuts off. This is called "anti-islanding protection" and it's a legal requirement under Australian Standards (AS/NZS 4777).
The reason is worker safety. When the grid goes down, energy workers are sent out to repair lines and restore power. If your solar kept feeding electricity into those lines, a worker could be electrocuted — even on a line that appears to be dead. So the standard requires your system to detect the outage and stop exporting within milliseconds.
The same is true even when the sun is blazing and your panels are generating peak output. Grid goes down, inverter shuts down. No exceptions for standard grid-tied systems.
So What Do You Actually Need for Backup Power?
There are a few options, at different price points:
Option 1: A Battery with Backup Mode
Most modern home batteries — Tesla Powerwall, SolarEdge, Sungrow, BYD — include a "backup" or "off-grid" mode. When the grid fails, the battery and solar automatically isolate your home from the grid and keep powering a subset of your circuits.
This is now the most popular backup solution in Australia. You get solar generation during the day plus stored energy when the sun's not out — all seamlessly switching over in milliseconds when a blackout hits.
Important caveat: not all batteries do this automatically, and not all batteries back up the whole house. Read the spec carefully. Ask specifically: "does this battery provide automatic backup during a grid outage?" and "does it back up the whole home or just certain circuits?"
Option 2: A Hybrid Inverter
A hybrid inverter is designed from the start to work with a battery and to provide backup capability. If you're installing solar now and know you want battery later, a hybrid inverter (like the Sungrow SH series or Fronius Symo GEN24) makes adding backup easier and cheaper down the track.
Option 3: An Off-Grid System
Full off-grid systems aren't connected to the grid at all. They're common in rural areas where grid connection is expensive or unreliable. They're also substantially more expensive — you need to size the battery and generator backup for your worst-case usage, including cloudy winter weeks.
The Fine Print on Backup
Even with a battery backup system, you may not be able to run everything. Large loads like air conditioning, electric ovens, or pool pumps may not be covered by the backup circuit unless you've specified this upfront.
If backup power matters to you, say so at the quoting stage. A good installer will design the system around your priority loads — typically lights, fridge, phone charging, and router. Full-house backup adds cost but is possible.
Blackouts are one good reason to consider a battery. But whether the numbers stack up depends on your usage and electricity costs. Upload your bill to GridBeater and we'll show you the solar-only and solar-plus-battery figures side by side.
See your solar and battery savings estimate → Upload your bill free at GridBeater