What happens to my solar when the power goes out?

This surprises almost every new solar owner the first time it happens. The sun is out, the panels are on the roof, and the house has no power. The system is behaving exactly as it is required to.

Why it shuts down

It is called anti-islanding protection. If the grid goes down, line workers need to be able to assume the network is dead. A solar system feeding power back into the street would create live wires on a network someone is working on. Inverters are therefore required to detect grid loss and disconnect within moments.

What actually changes it

• A battery on its own does not necessarily change it. Many battery installations are grid-connected only and will also shut down.
• Backup capability is a separate feature and a separate cost. It requires additional switchgear that isolates your house from the grid so the system can safely keep running.
• Backup is usually partial. It typically powers a nominated essential circuit or two rather than the whole house, because running everything would flatten a battery quickly.
• There is often a brief interruption during changeover unless you have specified an uninterruptible setup.

Whatever the configuration, the installer must hold current accreditation with Solar Accreditation Australia for the system to earn the federal certificates that fund its discount.