How Do Plug-In Solar Panels Work in the UK?

What is a plug-in solar panel?

The official definition is worth knowing because it tells you what you are buying. A plug-in solar device has at least one solar panel, a grid-following microinverter, a lead fitted at the factory with a standard three-pin plug, and a mounting system. The lead is the only way it is meant to connect. There is no opening the box and wiring it into anything.

That last point is why you can fit one yourself. Nothing is spliced into your consumer unit. It goes in a socket the way a kettle does, just in the other direction. The same idea is used in the US, where the limits and certification differ, as we explain in how plug-in solar works in the US.

How it works, step by step

1. 1
   The panel makes direct current

   Sunlight, even on a grey day, produces a small current in the panel. It is the wrong kind for your home, which runs on alternating current.
2. 2
   The microinverter converts it

   The inverter switches the current to match your mains supply and its timing. "Grid-following" means it copies the grid rather than making its own, which is what keeps it safe to connect.
3. 3
   The plug carries it in

   The lead goes into a socket on one of your circuits. The power joins whatever else is flowing on that circuit.
4. 4
   Your home uses it first

   Anything switched on takes solar power before it takes grid power. Your meter simply records less imported electricity.

Does it send power back to the grid?

It can, but the kits are small on purpose. At most 800 W leaves the inverter, and most homes have something running in the daytime, even if it is only the fridge, the router and standby loads. Much of what the panel makes gets used before it reaches the street.

If you are out all day, more will flow out. The rules we have read do not set up a payment for that surplus. We are still checking whether any scheme pays for it, so treat exported power as a bonus you should not count on.

What happens in a power cut?

The kit switches off. Every plug-in device has to stop generating when the grid goes down, because otherwise it could push power into cables that engineers think are dead. This is called anti-islanding, and the specification builds it into how the plug and inverter are designed.

What can a plug-in kit power?

Think of it as topping up your baseline. At full sun an 800 W kit can carry a fridge freezer, a router, a laptop and a few lights all at once, with some to spare. On a dull day it will make far less. It will not run an electric shower or an oven, and it does not try to. Those loads still come from the grid.

How much you actually save depends on what is running while the sun is out. Someone home all day gets more out of it than someone who leaves at 7am. To put numbers on it, enter your own postcode area and kit size in the UK savings calculator, or read what a £400 kit costs and how long it takes to pay for itself. Seen a supermarket kit advertised? Here is what we know about Lidl's plug-in solar panels.

What are the rules?

Plug-in solar became legal in Great Britain on 27 Aug 2026. The device must be on the ENA register, you get one per household and you tell your network operator within 28 days. Our guide to the UK plug-in solar rules and the 28-day notice walks through each step, and the UK plug-in solar hub has everything for Great Britain in one place.