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Solar · Advice

Will my solar panels keep my house powered in a power cut?

Short answer

No, not on their own. Grid-tied inverters must switch off when the grid fails so they cannot feed power onto lines engineers are working on. Backup needs a battery with an emergency power circuit or a whole-home backup gateway, and even then output is limited by the inverter and battery.

Last checked 24 September 2026 · 3 sources

In more detail

  • Tesla UK: 'A traditional solar system without a Powerwall does not function during a grid cut'; with Powerwall, solar can recharge the battery off-grid.
  • Loss-of-mains (anti-islanding) protection is required by the G98/G99 connection rules.
  • EPS (emergency power supply): a separate circuit/socket fed by the inverter during an outage; GivEnergy's 2023 guide quotes ~5 seconds delay and EPS limits of 1.25-3.6 kW depending on model.
  • Whole-home gateway: GivEnergy Gateway claims 20 ms switchover; Tesla claims backup restored 'in a fraction of a second' but owners report brief blackouts.
  • Plug-in solar gives no power in an outage.
  • Tesla: Powerwall enters standby below 10%; an overload stops backup and it retries within a minute.

The facts, dated

  1. 01
    Traditional solar without battery backup does not function in a grid cut (Tesla UK)

    manufacturer · UK · checked 24 September 2026 · Tesla

  2. 02
    GivEnergy EPS energises approximately 5 seconds after loss of grid — 5 s

    manufacturer · UK · checked 24 September 2026 · GivEnergy

  3. 03
    GivEnergy Gateway switchover time — 20 ms

    manufacturer · UK · checked 24 September 2026 · givenergy.com

What we saw in the field

[QA review 2026-09-24] C2-8/C2-9 AGREE. C1-8 gateway hum UNVERIFIABLE. | Earlier notes: Customer 2 lost power ~45 minutes overnight in a 24-hour cut with 20% reserve and saw devices reboot on switchover: consistent with reserve running out overnight and with owner reports that switchover is not always seamless. Customer 1's gateway switches cleanly (early unit hummed).

Sources

Last checked: 24 September 2026