What to watch out for before buying plug-in solar in the UK
The market is about to change quickly, and that means a lot more products, a lot more confident marketing and probably a fair bit of confusion.
From 27 August 2026, compliant plug-in solar gets a proper UK route. That is good news. But it does not mean every 800W inverter, European balcony kit or product with a UK plug suddenly qualifies.
The biggest mistake after 27 August will be assuming that “plug-in solar is legal” means “anything with a plug is legal”.
The new route is narrow. Only products that comply with the final UK Interim Product Specification can use it.
First check: can the exact kit be registered?
The ENA now has a dedicated householder portal at myplugin.solar. It only allows approved devices to be selected. Before paying for a kit, I would search the exact make/model there and on the ENA device register.
Do not accept “the inverter is G98 approved” as a substitute. The complete plug-in product is what matters.
1. Check the complete product, not just the inverter
This is the first thing I would look at.
A lot of buyers will see an inverter that has G98 credentials, an 800W or 799VA rating and a lead that fits a UK socket and assume that is enough.
It is not.
The new framework is built around the complete product: inverter, panels, manufacturer-supplied plug and lead, mounting arrangement, instructions and the rest of the required safety provisions.
If a seller is effectively saying “buy this inverter, then choose your own panels and add this plug lead”, I would not assume that combination qualifies under the new self-install route.
2. Look for the manufacturer-supplied UK plug
The final IPS requires a manufacturer-supplied non-rewireable BS 1363 plug fitted with a 5A fuse.
That wording is quite specific, and I think it is one of the easiest checks for consumers to understand.
If the lead is optional, separately sourced, fitted by the retailer after the fact or supplied with a normal rewireable plug, I would want a very clear explanation of how the complete product meets the UK specification.
Do not confuse “it physically plugs into a UK socket” with “this is the plug arrangement required by the new rules”.
3. Do not buy on “800W” alone
People are going to use 800W as shorthand, but the final UK limit is actually 800VA continuous AC output and 3.5A continuous AC current.
The specification also allows up to 2,000W of connected PV modules, which is why simply looking at the total panel wattage can be misleading.
Read the 800W / 800VA guide if a product listing mixes AC inverter output and DC panel wattage together.
4. Check whether a battery is included
This one matters because some of the most heavily advertised European balcony-solar systems now include storage.
The new UK plug-in solar IPS does not cover plug-in battery systems or plug-in solar products incorporating electrical energy storage.
So if a seller says “UK plug-in solar legal from 27 August” next to a battery-based product, I would not assume the same legal route applies.
See the plug-in battery storage UK guide.
5. Check the socket circuit, not just the socket
A perfectly good-looking socket does not tell you everything you need to know about the circuit behind it.
The manufacturer's instructions should explain how to identify which final circuit the socket belongs to and what protection is required.
If you cannot identify the protective device at the consumer unit, or the board is old and unclear, that is a point where I would stop guessing and get professional advice.
Our socket, ring final and radial circuit guide covers this in detail.
6. Do not assume two sockets means two systems
This will almost certainly become a source of bad advice online.
The product specification discusses one device per final circuit, but the same final document says the current G98 network position restricts this to one device per household unless G98 is amended.
So I would not buy two kits on the assumption that an upstairs ring and downstairs ring automatically lets you run two systems.
7. Check the mounting system properly
Plug-in solar is often sold as though mounting is a minor detail. It is not.
A solar panel is a large flat object exposed to wind. A balcony, fence, wall, shed or ground frame needs to hold it safely through bad weather, not just on the calm day when it was installed.
Under the new framework the mounting arrangement forms part of the complete product requirements. If you have to invent your own brackets, drill a different structure or substantially change the supplied mounting method, I would stop and check whether you are still using the product as intended.
8. Be suspicious of vague compliance wording
There is a big difference between these claims:
- “G98 compliant inverter”,
- “CE/UKCA marked”,
- “designed for European balcony solar”,
- “799W output”, and
- “this complete product complies with the final UK Plug-in Solar Interim Product Specification”.
The first four can all be useful bits of information. None of them, on their own, proves the fifth.
9. Check the DNO paperwork before you buy
Network notification does not disappear just because installation gets easier.
The final specification requires manufacturers to provide instructions for the DNO process. I would want to see that before buying, not discover afterwards that the retailer has no idea what information you need.
The registration guide and G98 form guide explain the paperwork.
10. Treat old consumer units with more caution
The government safety study found that representative plug-in PV systems could operate safely under the conditions tested, which is reassuring.
But the final specification also recognises that UK homes vary massively, and the IET remains more cautious about connecting these systems to older or uncertain domestic installations.
If your board is old, labels are missing, RCD protection is unclear or you already know the installation has issues, I would get it checked before plugging generation into it.
11. Above 960W of panels, read the small print
The product can have up to 2,000W of connected PV modules, but the final IPS says professional assessment of the electrical installation should be considered above 960W.
That is not a second legal inverter limit. It is a recommendation to take the condition of the installation more seriously as the DC array gets larger.
12. Ignore savings claims that do not mention self-consumption
This is still one of the easiest ways to oversell small solar.
If your home is only using 200W during the middle of the day and the system is generating 700W, you are not necessarily being paid the same retail rate for the extra 500W that leaves the house.
Your real savings depend heavily on how much generation you can use yourself.
Before buying, I would measure or estimate your daytime base load and compare that with likely generation. Our base-load monitoring guide explains how.
13. Placement still matters more than the brochure
A technically perfect kit in a terrible location can still be a poor investment.
Shade, orientation, panel angle, nearby buildings and seasonal sun all matter. Balcony railings and fences can be particularly deceptive because the panel may spend large parts of the day in shade.
Do not buy based on the panel's nameplate wattage and assume that is what you will see at the socket all day.
14. Check who actually supports the product in the UK
This is something I would put much higher up the list than price.
If the inverter fails, the app stops working or the DNO asks for a document, who are you dealing with?
I would favour products with:
- a clear UK manufacturer or importer,
- proper manuals,
- accessible technical documents,
- UK warranty support,
- spares and replacement leads where appropriate, and
- someone willing to answer compliance questions in writing.
15. Do not let “DIY” make you overconfident
The whole point of the new route is to make straightforward small solar accessible without automatically needing a full professional installation.
That is not the same thing as saying there is no judgement involved.
If you cannot follow the consumer-unit checks, cannot identify the circuit, need fixed wiring changed or are unsure whether the mounting is safe, that is the point to get help.
See do I need an electrician for plug-in solar?
My buying rule:
I would not buy any plug-in solar product unless I can answer five questions clearly: what exactly is the compliant product, where is the evidence, what circuit am I using, how is it mounted, and what is the DNO process?
If the seller cannot answer those, I would keep my money.
Sources
Related guides
This is general buyer guidance, not a substitute for the manufacturer's instructions or a site-specific electrical/structural assessment.