Plug-In Solar Rules in the UK: 800VA, G98 and Permissions

Rule one: 800VA, and it is measured at the inverter

The legal ceiling is 800VA of alternating current pushed into your home. That figure belongs to the microinverter, the box that sits between the panel and the plug. It is not a limit on the panel.

So a 625W panel behind a 620VA microinverter is compliant. So is a 700W panel behind the same unit. The inverter is a valve, and it cannot pass more than its rating no matter how much the panel offers it.

Why would anyone deliberately fit a panel larger than the inverter? Because panel ratings are measured in bright, direct, perpendicular light at 25 degrees, and Britain supplies that for perhaps a few dozen hours a year. Oversizing means the system crosses into useful output earlier each morning, stays there later, and performs better under the cloud that dominates our year. The cost is a little clipping on a handful of clear summer afternoons.

Where people trip up

• Buying by panel wattage. A listing that shouts "800W kit" is telling you about the panels. Look for the inverter's AC rating.
• Adding a second kit. The ceiling is your household total, not per device. Two 600VA units is 1200VA and puts you outside the rules.
• Assuming a 1000W inverter is fine because the panel is small. It is the inverter's rating that counts, not what you happen to have plugged into it.

Rule two: you must notify, and it is free

Within 28 days of plugging in, tell your Distribution Network Operator under a standard called G98. Three things people get wrong about this:

1. It is not an application. You are informing them, not asking. A compliant device cannot be turned down.
2. It costs nothing. Anyone charging a fee for a plug-in G98 is charging you to fill in a form.
3. Your DNO is not your supplier. It is whoever owns the cables in your street, decided by geography rather than by who bills you. Your supplier will tell you which one it is.

The form wants the device model and its type-test evidence, which is why the next rule matters.

Rule three: the inverter has to be registered

Compliant microinverters are type tested and listed on the Energy Networks Association register. That listing is what makes your notification straightforward.

This is also the quickest way to sort the market. A great many kits reaching UK listings right now were built for the European market, and some arrive with a Schuko plug and no fused UK equivalent in the box.

Rule four: permission is about the building, not the electricity

The electrical rules are national. Whether you may attach something to a wall is entirely local.

Rule five: the savings depend on your day, not your roof

The government estimate is up to £110 a year and roughly a fifth of household electricity. Both figures assume you use the power as it is generated.

There is no battery in a plug-in system and no export payment. Electricity produced while the house is empty is not stored and not sold. It simply does not happen. That makes your daily routine the single biggest variable, ahead of orientation, tilt or panel choice.

The cheapest way to improve the number is not equipment. It is running the dishwasher, the washing machine or a slow cooker in the middle of the day.

What one panel actually powers

A single 465W or 625W panel covers background draw and small loads: fridge, freezer, router, laptops, television, lighting, a slow cooker. It will not run an electric shower, an immersion heater or a car charger, and anyone implying otherwise is selling rather than explaining.

Before you order, check these seven

1. Inverter AC rating of 800VA or less. This is the legality test.
2. ENA registration reference for that exact model.
3. A fused UK plug and lead in the box, not a European one.
4. Panel weight and length against your mounting. A 625W panel is about 2.4m and 33kg. That is a two person lift and too much for many railings.
5. IP67 on the inverter. It lives outdoors permanently.
6. Inverter warranty read separately from the panel warranty. Panels routinely carry 25 years; the inverter is the part that fails.
7. Monitoring. Without it, a silent failure can cost you a season before anyone notices.

Common questions

Does this apply in Northern Ireland?

The 27 August 2026 change covers Great Britain. Northern Ireland has its own framework, so confirm locally before buying.

Do I need an electrician?

Not for a kit designed to use a 13A socket, which is the whole idea. You do need to file the G98. If you would rather have the inverter hard wired than plugged in, that is electrician work.

What if I skip the notification?

You are operating outside the rules and your network operator has no record of generation on their network. It takes minutes and costs nothing, so there is no good reason.

Can I add a battery later?

Not inside the plug-in category as it currently stands. Storage moves you into a fixed installation with the approvals that come with it.

Does it need cleaning?

Rarely here. Rain does most of the work. A panel mounted flat holds more dirt than a tilted one, which is one more argument for an adjustable mount.

How long until it pays for itself?

On the government's own figures, a kit at around £240 against savings approaching £110 a year pays back in roughly two to three years if you are home during the day, and considerably longer if you are not. Treat any shorter claim with suspicion.

If you want the short answer

One panel, one certified microinverter under 800VA, a UK plug and a mount that suits where it is going. We build the inverter, so we can hand you the registration reference your network operator will ask for.

See the plug-in solar kits

Figures quoted are the UK government's published estimates from the announcement of 26 August 2026. Rules change and this is general information rather than legal or electrical advice. Confirm current requirements with your Distribution Network Operator and check your own permissions before buying.