Respuesta Rápida
Many solar panel owners assume their system will keep their lights on during a blackout. La configuración óptima depende de su consumo real, la orientación del tejado, las necesidades de batería y la elección de la tarifa de exportación adecuada.
The grid shutdown rule (anti-islanding protection)
The most surprising discovery for new solar owners is that their system shuts down completely during a power cut. Even if the sun is shining brightly, your home will lose power.
This is an intentional safety feature called anti-islanding protection, mandated by Spanish electrical regulations. Inverters must shut down immediately when they detect a loss of grid voltage. This prevents the panels from feeding electricity back into the local grid, which could electrocute utility engineers working to restore power.
Why a standard battery does not keep your lights on
Having a solar battery does not automatically change this rule. If you have a standard grid-tied battery installation (without backup equipment), the battery will also shut down during an outage.
To run your home from your battery during a power cut, you must isolate your home from the external grid. This requires specific gateway or backup box hardware.
The hardware required for real backup power
If you want to keep your lights and appliances running during an outage, your solar setup must include:
- A Hybrid Inverter: An inverter designed to handle both DC solar panels and battery storage while supporting off-grid operations.
- An Automatic Transfer Switch (ATS) or Backup Box: A physical switch (such as a Huawei Backup Box or Tesla Gateway) installed between your inverter and electrical panel. It isolates your home from the grid during a blackout, creating a local “island” powered by the battery and panels.
- Critical Load Circuit Wiring: You must choose which appliances to back up. Sizing the backup system to run your entire house (including air conditioning or pool pumps) is extremely expensive. Most homeowners back up only critical circuits (refrigerator, lights, internet router, water pump).
Next steps for backup planning
Adding backup hardware after the initial installation is much more expensive than installing it from day one. If you live in an area of Málaga or the Costa del Sol with unstable power grids, ensure your initial quotation includes a hybrid inverter and a backup gateway.
For electricity tariff switching and post-install bill optimisation, we work alongside weSwitchSpainto optimize your tariff so you aren’t overpaying for standing charges while maintaining a resilient home backup setup.