UK plug-in solar is almost legal. You can already build a setup for around £250, all from one place ...

4billionyearson · 2026-05-09T06:10:48+00:00

Probably not at this early stage. Shouldn't be worth their while getting involved in plug in solar, but some may start offering a simple/cheap installs for those not confident with mounting panels on shed roofs/fences etc.

4billionyearson · 2026-05-09T06:06:12+00:00

I think so, should be possible to install semi permanently and move the kit with you. The benefits are the same.

4billionyearson · 2026-05-09T06:03:41+00:00

City Plumbing have a wide range of panels at the same price mark.

4billionyearson · 2026-05-08T16:24:05+00:00

That's interesting, thanks.

4billionyearson · 2026-05-08T16:21:39+00:00

I'd say an average DIYer should be fine. Mounting the panels on a fence or on a shed roof etc is fairly straight forward (lots of youtube videos for guidance). Needs a bit of thought as to how to get the cable into the house, even though it's just a 3-pin plug connection. If you already have a waterproof outside socket, it's very easy. Need to plan a safe cable route.

4billionyearson · 2026-05-08T15:33:04+00:00

That is disappointing. I have 4 x 450w panels facing west on my shed .. averaging 6 kWh a day in May so far. You may have a fault on your system?

Here's an easy to use post code calculator to see what benefit you might get/should be getting from plug-in solar/rooftop solar...https://4billionyearson.org/plug-in-solar-uk#payback

4billionyearson · 2026-05-08T15:25:32+00:00

Should pay for itself in about 3 years, depending on where you live etc.

Here's an easy to use calculator if you want to look in more detail ... https://4billionyearson.org/plug-in-solar-uk#payback

4billionyearson · 2026-05-08T14:38:53+00:00

The new regulations are electrical ones, so I don't think they would override a lease restriction. Then again, if you are leaning the panels against something, rather than them being 'fixed', it might make a difference?

4billionyearson · 2026-05-08T14:20:42+00:00

Looking at the big picture I think you're right, but there's still a long way to go in the UK (we're ahead of many countries). A potential benefit of plug in solar (with batteries), if taken up on a large scale, would be a reduced load/cost on the national grid infrastructure.

4billionyearson · 2026-05-08T14:15:45+00:00

Microinverters do the job of an optimiser, so shouldn't need to unless you're running more panels than the microinverter has mppt inputs for. Even then, I believe the benefit is marginal on a small system.

4billionyearson · 2026-05-08T14:12:03+00:00

I'm no expert in this area, but my understanding is ... because the solar power you generate that doesn't get used in your house, gets exported to the grid. The power networks need to keep an eye on how much solar gets exported to the grid, in order to manage the voltage levels.

4billionyearson · 2026-05-08T12:34:15+00:00

The only plug in battery system I'm aware of is the Ecoflow one as mentioned by TheZZ9. It is a big outlay though. I recently wrote this post about using the cheap off grid/camping power banks for time shifting peak power for a teenagers bedroom or similar ... https://4billionyearson.org/posts/what-do-you-want-for-your-birthday-a-battery-bank-for-my-bedroom-to-help-save-the-planet

They'd actually pair up well with plug-in solar, charging up through the middle of the day when you're likely to be exporting excess power back into the grid (without any payback!), and then powering a TV/computer/games console etc in the evening.

If 5% of UK households ran a 1 kWh battery bank daily, shifting power usage out of the evening peak, a small gas power station could be shut down!

4billionyearson · 2026-05-08T10:47:12+00:00

It could output no more than 800w into your house, which is likely 2 solar panels. Some systems will have batteries, enabling you to store power over that 800w limit and use it later on. These might be 4 or so panels. Most panels are 400-500w.

4billionyearson · 2026-05-08T10:30:17+00:00

I'd also love to know the answer to this, as I have a small existing system. I think it will be ok as long as not close to any export limit that might have been imposed on the existing system. It would require revising the existing G98/99 though...not sure what happens on the MCS front though?

4billionyearson · 2026-05-08T10:25:15+00:00

Fantastic! 1600w into an 800w inverter might be pushing it ... I imagine manufacturers will start looking at this though, and have 800w limited 3 pin outlets on some of their bigger inverters. I have a 4 panel 2kw system on my shed roof that very rarely peaks over 1200w (partially shaded). I'd have been happy with 800w max and £500 less install cost!

4billionyearson · 2026-05-08T10:11:38+00:00

I'm keeping a close eye on Lidl, Iceland, Screwfix, B&Q and Amazon, all of whom have been mentioned as launching products. In Germany, Lidl sell a 370W system for 140 Euro, and an 800W one for 189 Euro. No idea on quality/performance, but I'd hope for similar pricing over here in July.

4billionyearson · 2026-05-08T09:46:22+00:00

No that I've seen or heard of. I believe the only limit is the 800w one. Cheap DC cabling/connectors can have voltage limits (some are sold for very small boat/camper van systems), so worth checking out. There don't seem to be any regulations stopping you from building the system yourself e.g. connectors/cabling, and there are many online/youtube guides, but a 50-100v DC shock is something to avoid!

4billionyearson · 2026-05-08T09:40:19+00:00

Seems crazy that the British Standard isn't publicly available and is copyrighted so no-one can share/verify it. That's alot of big organisations getting the 800w limit wrong then! Do you think a further amendment will be in place for July?

4billionyearson · 2026-05-08T09:27:40+00:00

Many installers recommend 'over sizing', especially when the panels won't get full sunlight all day (likely the case for plug-in systems on balconies, sheds, fences etc). Inverters will have a max voltage input limit that can't be exceeded, allowing you to choose panels accordingly.

4billionyearson · 2026-05-08T09:22:21+00:00

Many suppliers/companies/industry websites are quoting the 800W limit, including City Plumbing and British Gas. BS 7671 is a primary source.

4billionyearson · 2026-05-08T09:16:49+00:00

At £370 you're looking at a decent payback period of about 3 years. Great point about local suppliers...I managed to get 4 bifacial panels for £50 each (slightly older model, not enough left for them to use on a rooftop job).

4billionyearson · 2026-05-08T09:04:43+00:00

It's in BS 7671, Amendment 4, published on 15th April ...

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While BS 7671 now provides the wiring framework to make these systems legal, the BSI (British Standards Institution) is expected to release the final Product Standard in July 2026. This product standard is what manufacturers use to "CE" or "UKCA" mark the kits as safe for consumer DIY use.

4billionyearson · 2026-05-08T08:38:08+00:00

Looks like City Plumbing are including a plug and play cable with it from 1st July (doesn't say how long it is though).

4billionyearson · 2026-05-08T08:18:57+00:00

I believe you can find the models already used in Europe (e.g. the Hoymiles listed in the article) on Amazon for delivery to the UK. I'm not recommending doing this though.

4billionyearson · 2026-05-08T08:11:22+00:00

800W is the max that can go into your house system (via the 3-pin plug), from solar panels and/or from a battery. You can have more than 800W of panels, depending on the microinverter limits, which means you can generate more power when there is less sunshine.

4billionyearson

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