Wattcheck
Articles

What we have checked, and what we found.

13 pieces, grouped by the category they belong to. Every one is grounded in something you can check yourself — the ENA type test register we mirror, or a primary source we link to. Where we wanted a fact and could not get it, the piece says so rather than filling the gap.

Across every category

The registers, the rules and the money questions that are not specific to one kind of equipment.

Your equipment isn't on the list. For most things, that means nothing at all.There is one public list of tested equipment, and it only covers things that send electricity back out to the street. Look up an ordinary car charger or a solar panel and you will find nothing — which is not a problem with either.

Plug-in solar

Plug-in solar hub →

Solar you plug into a normal socket. Since 27 August 2026 SI 2026/848 allows it without installer sign-off — at 800W AC or less, with no battery, by plug and socket.

We checked every plug-in solar kit on sale in the UK. Not all of them can just be plugged in.Every kit we could find on sale in the UK, checked against the rules that changed on 27 August. Four things turned up that a shopper would never spot from a product page.Why a "1260W" kit can still be under the 800W limitThe 800W limit is about what reaches your sockets. The number on the box is what the panels make in bright sun. They are different measurements, and only one of them is in the rules.Solar kits with a battery: you can buy one, but you can't just plug it inThe best-selling format is the one the new rules do not cover. It is not banned — it needs an electrician, which is the thing people were trying to avoid.How to check a kit has actually been testedThere is one public list of equipment that has passed the safety test, and one question that gets you a straight answer from a seller. Both take about thirty seconds.Is plug-in solar legal in the UK?Yes, since 27 August 2026 — if the kit ticks four boxes. "Plug-in solar is legal" and "this kit is legal" are not the same sentence, and the shop will not always tell you which one applies.What plug-in solar actually saves youThe government says up to £110 a year. We worked it out ourselves and got £106 — and every assumption behind that number is on the page, so you can change the ones that are wrong for your house.Your kit isn't on the tested list. Is that a problem?It is not contraband and you have not been sold a dud. What you lose is the right to simply plug it in — and there are three honest ways forward.You have to tell the company that owns the cables in your street. Their form won't let you.Plug one in and you have to tell your local electricity network company yourself — not the shop. Then you find their form asks for the name of the electrician you didn't use.

Home batteries

Home batteries hub →

Fixed home storage. A different regime entirely from plug-in solar: notified to your network operator under G98 or G99 and installed by a certified installer.

A home battery makes its money at night, not in the sunThe sun is optional. A battery charged at 8p and discharged against a 26p day rate earns the same in Inverness as in Brighton — which makes postcode the wrong question entirely.

Rooftop solar

Rooftop solar hub →

Panels fixed to a roof, wired in by an installer. The largest register we hold — and the one where MCS certification decides whether you get paid for what you export.

The same panels, 4p or 20p a unit. It depends who you buy your electricity from.What you get paid for the electricity you don't use varies five-fold between suppliers — and the decision is made when you pick an installer, months before anyone mentions tariffs.

EV charging

EV charging hub →

Vehicle-to-grid chargepoints — the ones that can push a car battery back into the house or the grid, and are therefore type tested like any other generator.

Seventeen car chargers in the whole country can send power back to your houseUsing your parked car as a battery for the house has been about to arrive for years. There is one public list of the chargers that can actually do it, and you can read the whole thing in a sitting.

Heat pumps

Heat pumps hub →

A guidance category rather than a hub. We hold no register for heat pumps: they are load rather than generation, so no ENA device type covers them, and the register that does govern them — MCS — is not licensed for republication.

You don't need loft insulation to get the £7,500 heat pump grantThat rule was scrapped on 8 May 2024 and never replaced. So was the one about needing a valid EPC. Both are still quoted at people as reasons they cannot apply.

What these are, and what they are not

Wattcheck is a testing house, not a seller. We mirror the official registers, list what vendors publish, and show the two beside each other. Nothing here is a compliance certificate, an electrical safety assessment, or legal advice.

Different categories are governed by entirely different rules, and we keep them apart on purpose. SI 2026/848 — the 800W cap, the no-battery test and the plug-and-socket test — applies to plug-in solar and to nothing else on this site. A product outside that route is not unlawful: it may be perfectly lawful as a fixed installation under the normal G98 or G99 process.