Living with solar

Do solar panels work in a blackout?

For a standard grid-connected system, no — it shuts down within seconds, even at midday in full sun. That surprises almost every new owner. It is a safety requirement, not a fault, and there is a way around it.

By Kieron Taylor, Founder, Solar Select · Updated · 6 min read

The 30-second take

  • A standard grid-connected solar system shuts down in a blackout, even in bright sunlight.
  • This is anti-islanding: a safety requirement under AS/NZS 4777.2 that protects electricity workers repairing the line.
  • Without a battery and backup wiring, your solar cannot power the house during an outage.
  • A battery alone is not enough — it needs a backup-capable inverter and a separately wired backup circuit.
  • Ask any quote exactly which circuits stay live in an outage. “Has a battery” and “has backup” are different products.

The short answer

If the grid goes down and you have a standard solar system, your solar stops too — within seconds, regardless of how much sun is hitting the roof. Your lights go out like everyone else’s.

This is the single most common surprise in Australian solar ownership. People reasonably assume that generating your own electricity means being independent of the grid, and for the great majority of systems that is simply not how it works.

Why it shuts down: anti-islanding

Grid-connected inverters are required to disconnect automatically when they detect the grid has failed. The requirement is set out in AS/NZS 4777.2, the standard governing grid connection of inverter energy systems in Australia and New Zealand, and every compliant inverter sold here implements it.

The reason is worker safety. During an outage, line workers repair what they expect to be dead conductors. A rooftop system feeding electricity back into the network would re-energise those lines — an “island” of live wire in a supposedly dead section. Anti-islanding removes that possibility.

“Your system is not failing when it shuts off in a blackout. It is doing the one thing that keeps a line worker alive.”

What it takes to keep the lights on

Three things have to be true before solar can power your home during an outage, and a lot of quotes only deliver one or two of them.

  • Storage. A battery, so there is energy available when the sun isn’t shining and the grid isn’t there.
  • A backup-capable inverter. It must be able to form its own stable grid — disconnecting from the network while continuing to supply your house. Not every hybrid inverter does this.
  • Backup wiring at the switchboard. A separate backup circuit, so the protected loads are physically isolated from the grid connection during an outage. This is electrical work, and it is a real line item.

Miss any one of those and you have a battery that saves you money on your bill but goes dark with everything else in a blackout. That is a legitimate product — it just is not the one most people picture when they buy “a battery for blackouts”.

The question to ask every quote

Ask exactly this: *“In a blackout, which circuits stay live, and for how long?”* A good installer answers with specifics — these power points, this lighting circuit, the fridge, not the air conditioning or the oven — and an estimate of how long that will last on a full battery.

Two battery quotes at similar prices can differ enormously here. One might include whole-home backup with substantial switchboard work; another might include no backup at all. Comparing them on price alone is comparing different products.

  • No backup — the battery cycles for bill savings only, and shuts down in an outage with everything else.
  • Essential circuits backup — a nominated set of circuits stays live. The most common and cost-effective option.
  • Whole-home backup — the entire house stays live, subject to the battery and inverter being able to carry the load. More switchboard work, more cost, and heavy loads may still trip it.

A word on installation quality

Backup wiring is among the more demanding parts of a residential solar installation: it changes how the switchboard behaves under fault conditions, and it must isolate correctly every time. It is not the place for the cheapest available crew.

The Clean Energy Regulator inspected 1,278 home battery installations between July 2025 and April 2026 and classified more than 60% as substandard and 1.2% as unsafe — findings that included incorrect labelling, exposed wiring and missing isolators, mostly on well-known hardware.

If blackout resilience is why you are buying, make that explicit at quote stage and make every installer answer the circuits question the same way. Get matched with 2-3 vetted installers and compare the answers, not just the prices.

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Sources

Every quantitative claim on this page traces to one of the sources below — government, manufacturer, or independent AU industry reference. Last verified 2026-08-16.

We use AI to help research and draft. Claims are traced to the sources below and dated. Where we haven’t got a source, we say so on the page — treat that as a starting point and do your own research.

General information only. It doesn’t take your circumstances into account and isn’t legal, financial, insurance or electrical advice. Rebates, tariffs, network rules and product terms change — confirm anything you plan to rely on with your installer, insurer, retailer or distributor, and see our terms.

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