How to Buy a Legal Plug-In Solar Kit in the UK: 8-Point Checklist

Short answer: buy a kit that is 800 W or less, has a moulded BS 1363 plug with a fuse of 5 A or less, is listed on the ENA Type Test Register, needs no adaptor or extension lead, and comes without a battery. Then check where you'll mount it, get permission if you rent or own a leasehold flat, and notify your DNO once it's connected.

The rules come from the government's Plug-in Solar Device Interim Product Specification (version 2, July 2026), which kits must meet to be plugged in legally. The overview is in plug-in solar in the UK: what changed. This page turns it into a shopping checklist.

The 8-point checklist

1. Output of 800 W or less. The limit is 800 VA and 3.5 A of AC output. Panel wattage can be higher (up to 2,000 W in total), but if it exceeds 960 W the specification suggests a professional check of your wiring.
2. The right plug. A BS 1363-1 three-pin plug with partially insulated pins, moulded on (not rewireable), with a BS 1362 fuse of no more than 5 A. If it has a European plug or comes with an adaptor, don't buy it.
3. Registered with the ENA. Manufacturers must register devices on the Energy Networks Association Type Test Register before sale. Ask for the system reference and look it up. A CE or UKCA mark is not the same thing.
4. No battery. Plug-in devices must not be used with battery storage, so solar-plus-battery bundles don't qualify for the plug-in route.
5. A suitable socket. You'll plug directly into a fixed socket: no extension leads or multi-way adaptors. If you need an outdoor socket, it should be at least IP65-rated and fitted by a competent electrician.
6. A suitable place to mount it. Not on timber balconies, timber or ACM/MCM/HPL cladding, buildings under fire-safety remediation, or a wall shared with a neighbour. Keep it clear of escape routes and shared walkways.
7. Permission if you need it. Landlord, freeholder or managing agent; listed building consent or planning advice in conservation areas.
8. One per household. Under the current network rules, only one plug-in device is allowed per household.

After you buy

• Install it following the manufacturer's instructions, using only the supplied or recommended brackets and fixings.
• Notify your distribution network operator. It's mandatory; the London Fire Brigade recommends doing it within 28 days.
• Tell your home insurer.
• Check production in the app and stop using the kit if you notice burning smells, buzzing, overheating or repeated tripping.

Which size makes sense in the UK?

With UK homes typically using a couple of hundred watts during the day when nobody is in, an 800 W kit (often two 400 to 450 W panels) suits most households, and a single-panel kit suits small flats. Because export payments generally aren't available for plug-in kits, a larger kit mostly gives power away. See which size you need for the reasoning (written for US kits, but the logic is the same).

Is it worth it?

The government estimates savings of up to £110 a year. At the October to December 2026 price cap of 26.32p per kWh, every 100 kWh you use from your panels saves about £26. A south-facing balcony with little shade is the best case; a north-facing one rarely pays off.

Frequently asked questions