Why does my solar kit stop working when the power goes out?

Grid-tied inverters must switch off when the grid fails so that they never feed electricity into lines that engineers assume are dead. The kit needs the grid as a reference; without it, the inverter stays off until the grid returns.

Can I run my whole house from a power station?

Not in a practical sense. A portable power station supplies devices plugged into it. Supplying house circuits requires a transfer switch installed by an electrician, and even then the capacity covers only selected loads for a limited time.

Can a petrol generator be used indoors?

No. Combustion generators produce carbon monoxide and must only be run outdoors, away from windows and doors. Battery-based power stations do not have this risk and can be used indoors.

How long do I need to plan for?

Most power cuts in Europe are short, but storms or technical faults can cause longer outages. Civil protection authorities recommend general household preparedness; base your plan on your own priorities and local risks.

Backup power for a blackout: what actually works

A standard plug-in solar kit does not help in a power cut. Its inverter is required to switch off as soon as the grid fails and stays off until the grid returns, even in full sunshine. To keep essential devices running you need equipment that can operate on its own: a portable power station, a battery with a dedicated off-grid socket, or a home battery system that has been designed and installed for backup. This guide explains the options and how to plan safely.

Why plug-in solar switches off

Every grid-tied inverter contains grid protection. It monitors voltage and frequency and disconnects when they disappear or move outside permitted limits. In Great Britain, small generators must meet the network rules in Engineering Recommendation G98; in Germany, the equivalent requirements are in VDE-AR-N 4105. The reason is safety: during a power cut, network engineers work on lines that must stay dead. An inverter that kept feeding power could endanger them. The details are covered in how plug-in solar works.

So the question is not how to keep the plug-in kit running, but which device takes over.

The options compared

Option	What it supplies	Installation	Typical use
Power banks and battery lights	phones, small lights	none	short outages, basic needs
Portable power station	devices plugged into it	none	router, fridge, lights, medical devices with care
Battery with off-grid socket	devices plugged into that socket	as for the battery	plug-in solar households wanting some backup
Home battery with backup function	selected or all house circuits	qualified installer	longer outages, larger loads
Combustion generator	devices or circuits via transfer switch	outdoors only; transfer switch by an electrician	rural homes, long outages

Portable power stations

A power station is a battery with an inverter and sockets. You plug devices directly into it. Models in the 1 kWh class can run a router and lights for a day or more, and with care a fridge for some hours. Some can be recharged with solar panels during longer outages. Our data sheet comparison of power stations covers capacity, output, cycles and UPS switchover.

Batteries with an off-grid socket

Some plug-in solar batteries have a separate socket that keeps working when the grid fails. Only devices plugged into that socket are supplied; the grid-tied output still switches off. Check the data sheet if this matters to you; see battery systems compared.

Home batteries with backup

A fixed home battery can supply house circuits during a blackout only if the system includes a backup function and a switching device that separates your home from the grid. Some systems supply a few selected circuits, others the whole home. This is planned and installed by a qualified installer. Sizing for backup differs from sizing for savings; see how big a home battery should be.

Safety rules that are not negotiable

Never back-feed through a socket. Do not connect a power station or generator to a wall socket with an improvised cable. It can put lethal voltage on exposed plug pins and on the grid side.
Transfer switches are electrician work. Connecting backup power to house circuits requires a properly installed changeover or transfer switch.
Generators stay outdoors. Combustion engines produce carbon monoxide.
Mind the load. Do not exceed the continuous output of the device, and keep cables and extension leads in good condition and rated for the load.

Plan by priority

List essentials. Lighting, the router for communication, phone charging, the fridge or freezer, and any medical devices.
Estimate power and hours. Use rating plates or measure with a plug-in energy meter.
Add up watt-hours. Compare with the usable capacity of the device you are considering.
Keep it charged. Check the charge level every few months and top up.
Test it. Switch off the mains to a device and run it from the backup for an hour.

People who depend on electrically powered medical equipment should also talk to their supplier and network operator; in Great Britain, network operators keep a Priority Services Register.

Preparedness beyond electricity

Equipment is only part of the picture. Torches with spare batteries, a battery or wind-up radio, charged power banks, drinking water and food that needs no cooking make a power cut much easier to handle. The UK government’s Prepare guidance gives practical household advice for emergencies, including power cuts.