What is plug-in solar and how does it work?

max inverter output

800 W

max panel power

2,000 W

per household

1 kit

How does plug-in solar work?

A kit has three main parts:

• Panels. One to four solar modules. The product specification allows up to 2,000W of panels in total, with no more than two in series and no Y-connectors.
• A microinverter. This turns the panels’ DC into mains AC and syncs it with the grid. Its output is capped at 800W (800 VA, 3.5 A).
• A plug and mounting. A moulded BS 1363 plug (the normal UK three-pin type) with a fuse of no more than 5A, plus a bracket, frame or stand.

You mount the panels, run the cable to a fixed indoor or weatherproof outdoor socket, and plug in. Whatever is running in your home at the time, such as the fridge or router, uses the solar power first. Any surplus flows out to the grid.

What does the law allow?

Plug-in solar became legal to sell and use in Great Britain on 27 August 2026. The law, SI 2026/848, defines a “plug-in microgenerator” as a device that generates electricity from sunlight, has “a maximum rated alternating current output not exceeding 800 watts”, connects “by means of a standard plug and socket”, runs in parallel with the grid and doesn’t store energy. It must also meet the DESNZ Interim Product Specification.

In practice:

• 800W AC is the cap, measured at the inverter, not the panels. Extra panel wattage (up to 2,000W) helps on dull days, but the inverter clips anything above 800W.
• The kit must be listed as Compliant on the ENA Type Test Register. The specification makes manufacturers get this before selling. Our device list tracks the register.
• One device per household, under the network rules (G98) approved by Ofgem.
• You must tell your DNO, the company that runs your local network. See how to register.
• No batteries. Battery-integrated and plug-in battery products are outside the legal framework. See plug-in solar and batteries.

Full detail: is plug-in solar legal in the UK?

How is it different from rooftop solar or a power station?

	Plug-in solar	Rooftop solar	Portable power station
Size	Up to 800W AC	Usually several kilowatts	Rated by battery capacity (kWh)
Who sets it up	You	An installer wires it in	You
Battery	No, not allowed	Optional	Yes, it stores energy

A legal plug-in kit has no battery, so it only works while it’s connected to the grid. See plug-in solar vs rooftop and vs a power station.

How much does it generate and save?

It depends on where you live and which way the panels face. The DESNZ Impact Assessment models an 800W system at average UK sunshine:

Mounting	Generation a year
Facing south, tilted at 30°	about 690 kWh
Vertical, facing east or west	about 378 kWh

DESNZ’s press release claims savings of “up to £110 a year” and “up to 20% of an average home’s electricity use”. Those are upper-end figures. Your saving depends on how much of the output you use at home while the sun is shining.

Where can it go?

Common spots are a south-facing balcony railing, a garden stand, a wall or a flat roof. Mounting must be reversible and non-permanent.

If you rent or own a leasehold flat, you need permission first: see landlord and freeholder permission. In England, planning permission is usually covered by permitted development, with some exclusions.

What to do next

• Get a yield and saving figure for your own postcode and direction with the calculator.
• Check a kit against the rules with the compliance checklist and your sockets and wiring.
• See which Compliant kits you can buy today: in stock now.