Plug-in solar kits in the UK compared: sizes, prices and where to buy

We don’t rank plug-in kits, because we haven’t tested them. What we can do is explain where the real differences are, show what kits cost in late October and early November 2026, and work out how a one-panel kit compares with a two-panel one. If you haven’t read it yet, our guide to the UK rules covers the legal side.

What every approved kit has in common

To be sold as a plug-in device in Great Britain, a kit has to meet the government’s Interim Product Specification and be listed as compliant on the network operators’ Connect Direct register. On 3 November 2026, one tracker that reads the register counted 128 compliant devices from 28 manufacturers. Every one of them:

• delivers no more than 800 W of AC power to your socket, however many watts of panels it has,
• has a standard 13 A plug and switches itself off within a fraction of a second if the grid goes down,
• uses outdoor parts rated at least IP55 against rain and dust, and needs an outdoor socket with the same rating if the plug lives outside,
• comes with a mounting system, which the maker has to back with a structural analysis for UK wind and snow loads,
• warns you not to use extension leads, multi-way adaptors or plug-in RCD adaptors.

So the safety basics are the same across the register. The differences are in what you get for the money.

Where kits differ

Panel power. Single-panel kits run from about 400 W to 530 W. Two-panel kits run from about 800 W to over 1,200 W. Because the inverter caps the output at 800 W, extra panel power doesn’t raise the peak. It means the kit reaches that 800 W on more ordinary days and makes more in the morning, evening and winter. The specification also says that buyers of devices with more than 960 W of panels should consider having their wiring assessed by a professional first.

The mount. This matters more than people expect, because the approval covers the kit as the maker specifies it, mount included. Kits are sold for balcony railings, walls, gardens (ground stands) and flat roofs, and some “hybrid” mounts do two of those. Buy the version made for your spot. Be wary of bundles sold “without mounting”: the specification says a complete kit includes one.

The microinverter. A handful of inverters turn up again and again, from makers such as Hoymiles, APsystems and Fox ESS. The inverter decides the app, the monitoring and part of the warranty, so check what you’re getting.

The seller. You can buy from an energy supplier (Octopus), a builders’ or DIY merchant (City Plumbing, Homebase), the high street (Argos) or direct from a specialist brand. A supplier or a big retailer is easier to deal with if something goes wrong. A specialist brand may know its product better.

What kits cost

These are prices seen on sellers’ websites between late August and early November 2026, most of them gathered by the Plug-In Solar Register tracker. Prices and stock change weekly.

Octopus’s bundles use JA Solar 460 W bifacial panels, and the two-panel version uses a Fox ESS microinverter. Both include the mounting kit, and the two-panel price includes delivery. Stock has been patchy: Octopus said in a press release on 1 October that it had restocked twice in under four weeks.

One panel or two? A worked example

Take a home in London with electricity at 26.32p per kWh, the Ofgem price cap rate for October to December 2026. The European Commission’s PVGIS model gives the yearly output, and the share used at home is our assumption: lower for the two-panel kit, because more of its midday output exceeds what a typical home is using.

The two kits pay back in about the same time. The two-panel kit saves more each year, and it pulls further ahead if someone is home in the day to use the extra power. In Manchester, PVGIS gives roughly 13% less output than in London for the same kit.

If your spot gets only a few hours of direct sun, or faces east or west, one panel is usually the better buy: a second panel adds less than you’d think when the sun is only on it for part of the day.

A buying checklist

1. Find the exact model on the register. Search the Connect Direct database for the model number on the listing. Similar-looking kits from the same brand aren’t always approved.
2. Match the mount to your spot. Balcony, wall, garden or flat roof, and check the maximum installation height in the instructions if you live above the ground floor.
3. Check your socket. You need a fixed socket within reach of the cable, outdoor-rated if it’s outside. No extension leads or adaptors.
4. Look at your fuse box. Rewireable fuses mean a call to an electrician before you plug anything in.
5. Get consent if you rent or own a leasehold flat.
6. Register at myplugin.solar before you switch on. It’s free and takes a few minutes.

For fixing the panels safely, including the surfaces the rules don’t allow, see our guide to mounting balcony solar panels. If you’re wondering about adding a battery, read Anker Solarbank vs EcoFlow STREAM first: batteries aren’t covered by the plug-in rules.