Plug-in solar
What a plug-in solar kit can and cannot do
A plain-English look at the Great Britain rules, the 800W cap, and why the electricity you use at home matters more than the watt sticker.
Checked: Rules checked against GOV.UK and the Energy Saving Trust for this sample feature. The kits in the table are not hands-on tests.
Ranked on merit only How we rankA plug-in kit is a small generator with a 13-amp plug. It is not a rooftop array, and it will not zero a winter bill.
Quick verdict
Worth a calm look if you can put one compliant device in the sun and use the power while it is being made. Skip it if you want whole-home backup, a heat pump, or you are in Northern Ireland, where this rule does not apply.
Who it’s for
People in England, Scotland or Wales with a sunny balcony, fence or wall, daytime electricity use, and permission to put a panel outside if the building needs it.
Who it’s not for
Anyone expecting an 800W plug to run heating, a heat pump or an electric car, or anyone outside Great Britain. It is also the wrong tool if you want a battery wired into the consumer unit.
The rule, in one sitting
From 27 August 2026, a compliant plug-in solar device can be bought and plugged in at home in Great Britain.1 The useful limit is 800W of power into the home, and the practical network rule in the guides is one device per home, not one per socket.2 Panels on the device can be listed above that, but the power that reaches the wiring is what the cap is about.
Northern Ireland is not in that change. A landlord, freeholder or council may still have a say about the outside of a building. The government notice says to check before you buy.1
Why the sticker watts are not the saving
The Energy Saving Trust’s round figure is about 700 kWh a year for a compliant 800W device.2 A smaller kit is scaled down from that in our calculator. South and unshaded is the top of that simple model. East, west and shade take a published factor off it, and the page shows the multiplication.
Only the share you use while the panels are generating avoids the unit rate you type in. The default is the Ofgem cap unit rate for October to December 2026, 26.32p/kWh.3 Power you do not use is not given an export payment in this estimate. That keeps the sum conservative, and it keeps the working short enough to check.
What a rank on this site is allowed to know
When a kit is ranked, the score comes from the published criteria: the 800W rule, siting, monitoring, warranty and daytime use. A shop, a network or a commission is not an input. The same boundary that BotFinder and PriceSpotter use refuses those fields in the scoring package.
The prices beside the rank are a sample fixture. The lowest in-stock price is the headline. A cheaper out-of-stock price stays in its column and loses. That is a price fact, not a merit score.
How we tested
- This feature explains the published rule and the savings estimate. It is not a hands-on test of a kit.
- The merit marks on the kit table are arbitrary samples so the layout can sort. They are refused once placeholder mode is turned off.
- The savings calculator shows each step and names its sources. Orientation and shading are simplified factors, not an MCS survey.
- Shop prices are a fixture passed through the feed adapters. They are not live Currys, Screwfix or brand-shop prices.
Notes
- GOV.UK, 27 August 2026. The Department for Energy Security and Net Zero said compliant plug-in panels could be bought and used across Great Britain from 27 August 2026, each kit producing up to 800W. Back
- Energy Saving Trust, plug-in solar. The Trust describes the 800W limit, one device per home, and about 700 kWh a year from a compliant device. Northern Ireland is called out as not yet covered. Back
- Ofgem, October to December 2026 cap. The Direct Debit electricity unit rate in the cap averages 26.32p/kWh for 1 October to 31 December 2026. That is the calculator default, not a promise about your tariff. Back