Free guide
What to check before you buy a plug-in solar kit
Plug-in solar became legal in Britain on 27 August 2026, and the market filled up faster than the rules were explained. This guide is the set of things we wish somebody had told us: what the 800W limit actually applies to, the job the law gives you rather than the seller, what your insurer has said about all this (nothing, so far), and the single question that tells you whether a seller’s compliance claim is real.
It is free, it is about 4,000 words, and we wrote it from the primary sources — the Ofgem decision, the product specification, the six network operators’ own pages and twelve insurers’ published wording. Where those sources do not answer a question, the guide says so instead of guessing.
What is actually in it
Nine sections. No brand recommendations, no affiliate list, no “top 5 kits of 2026”.
- 01
The 800W cap is on AC output, not panel watts
The most common misreading in the market. A kit sold as “1,600W” can be entirely lawful, and a kit sold as “800W” might not be. Which number the law cares about, and how to find it on a spec sheet.
- 02
One device per household — not one per socket
G98 currently limits you to a single plug-in device per household. Government has said it intends to relax this to one per circuit; that change has not been made. Buy a second kit on the strength of a blog post and you have bought a kit you cannot lawfully connect.
- 03
The one question that verifies a seller’s claim
Ask: what is this device’s ENA System Reference? Every properly type-tested device has one, in a fixed format. Nobody in this market uses the phrase in their consumer copy, so it is not a question a sales page has been written to deflect. The guide explains what a real answer looks like and what the common non-answers mean.
- 04
Telling your network operator is your job, not the seller’s
Ofgem moved the notification duty onto the householder precisely because these things are self-installed. Three operators state 28 days from commissioning. We also cover the awkward part: most operators’ forms still ask for installer details a self-installer does not have, and what to do about that.
- 05
Your network operator, one by one
A table of all six: which have a plug-in page (none), which route to use, the deadline in their own words, whether a fee is published, and where the form assumes an installer. Including the one operator whose form a homeowner can actually complete.
- 06
Insurance: what twelve insurers have published
Nothing. We checked all twelve. Ofgem explicitly made insurance your problem and the industry has not yet responded. Four questions to put to yours in writing before you buy, and why the seller’s line about unregistered kit invalidating your cover is not something anybody has actually said.
- 07
Not on the register is not the same as illegal
If you have already bought something that turns out not to be a plug-in device, you have three real options and only one of them is bad. The other two are set out honestly, including the fixed-installation route most people do not know they have.
- 08
Renting, leasehold, or a flat
There is no statutory right to install one of these, no model tenancy clause and no fast-track consent. What to ask your landlord or freeholder, in writing, before money changes hands.
- 09
What it will actually save you
How to sanity-check a payback claim, why export is worth much less than self-consumption for a device this size, and the assumptions any honest estimate has to show you.
Why we are giving it away
Wattcheck makes money from vendor listings and advertising, both of which are labelled as such wherever they appear. The guide costs us nothing to send and it is the clearest argument we have that the rest of the site is worth reading. If it is not useful, one click in the email takes you off the list and we will not have wasted much of your time.
We are not a lead broker with a blog attached. If you would like us to introduce you to suppliers, there is a box for that on the form and it is a separate decision from getting the guide. If you leave it alone, your address never leaves us.