Do solar panels work in a power cut?
A standard grid-tied solar system does not work in a power cut: it automatically shuts down for safety, to protect engineers working on the network. Only a battery with specific backup (islanding) capability, and the right wiring, can keep selected circuits running during an outage. Most basic systems do not include this by default.
Why solar shuts down in an outage
Grid-tied inverters are required to disconnect when the grid goes down, so they cannot feed electricity into lines that engineers may be repairing. This safety feature means panels stop generating to your home during a power cut unless you have backup-capable storage.
Getting backup power
- A battery with backup/islanding mode can power chosen circuits during an outage.
- It needs the right inverter and a backup gateway, specified at install.
- Backup capacity is limited to the battery's charge and the circuits it covers.
- Tell your installer if outage backup is a priority for you.
Frequently asked questions
- Will my battery automatically power my home in a power cut?
- Only if it has backup capability and the right wiring. Many home batteries are not configured for backup unless you ask for it.
- Can I run my whole house off the battery in an outage?
- Usually only selected essential circuits, and only while the battery has charge. Whole-home backup needs careful sizing.
Related questions
Indicative estimates based on UK average data. Last updated 27 May 2026.