Plug-in solar in the UK: the legal rules from 27 August 2026

A great deal of UK coverage has reported that a British Standards Institution product standard for plug-in solar was expected in July 2026. That was wrong. What was published on 16 July 2026 was the DESNZ Interim Product Specification, a departmental document based on the German pre-standard DIN VDE V 0126-95:2025-12. It carries legal weight because SI 2026/848 names compliance with it as a condition of the plug approval route.

An earlier draft of the specification, published on 16 June 2026, is now marked [Withdrawn]. If you are reading a technical claim sourced from that June draft, it is superseded. Government has committed only that work “will begin” on a long-term successor to the interim document. There is no designation, no named publisher and no timeline.

For a buyer the consequence is straightforward. There is nothing to be certified against, so certification claims are not evidence of anything. The check that does mean something is registration on the ENA Type Test Register, described below.

The connection must be made with a BS 1363-1 non-rewireable moulded plug with partially insulated pins, fitted with a BS 1362 fuse not exceeding 5 A, into a BS 1363-2 socket outlet. Where the plug and socket assembly is outdoors it must be rated to at least IP55 under BS EN 60529.

This single sentence disposes of the most common route people take. A large part of the European plug-in solar market ships with a Schuko (CEE 7/4) lead. A Schuko plug is not a BS 1363-1 plug, and a Schuko-to-UK converter is a plug convertor, which is expressly prohibited. There is no compliant way to fit a European kit to a UK socket using an adapter, and the prohibition does not soften because the adapter is fused, branded, or sold by a UK retailer.

It also rules out running the device from an extension lead or a multi-way trailing socket, which is how a good many balcony installations would otherwise be arranged. If the only socket within reach of your balcony is served by an extension lead, that is a problem to solve with an electrician and a new socket rather than with a longer lead.

The Interim Product Specification requires that manufacturers “shall register devices on the ENA Type Test Register (ENA Direct Connect platform) and obtain confirmation that the device has been assessed and identified as compliant prior to placing them on the market”. That is a pre-market obligation on the manufacturer, and it is the closest thing the framework has to a public list of compliant products.

The specification also requires product marking to state that DNO notification, both on connection and on disconnection, is mandatory, and to carry a link to the instructions. A device with no such marking, and no registration entry, should be treated as outside the framework regardless of how it is advertised.

Before buying, ask the seller for the ENA Type Test Register entry for the exact model and check it against the Energy Networks Association. A seller who cannot produce one is telling you something useful.

G98 Issue 2 Amendment 1 (2026) permits one device per household, and that is the operative rule on 27 August 2026. You cannot currently run two units on separate circuits, and a retailer suggesting otherwise is ahead of the rules.

The confusion is understandable, because the Interim Product Specification is written in anticipation of one device per final ring circuit, and the government has said it intends to move to a per-circuit limit. But it said so expressly “subject to a corresponding amendment to G98”. That amendment has not been made and carries no published date. Until it lands, 800 VA is a household ceiling rather than a per-socket one.

A stand-alone installation is also capped at a maximum surface area of 9 m², and is excluded on listed buildings and scheduled monuments.

Conservation areas and World Heritage Sites. The right is restricted where the device is installed on a wall, or on a roof enclosure, fronting a highway. Listed buildings. There is no permitted development right at all, and the listed building consent regime is entirely unaffected by these changes.

Transitional provision. Development permitted before 27 August 2026 may continue until 26 August 2027.

The government response is explicit that renters, leaseholders and residents in managed buildings “should obtain any permissions that may be required before installing a device”. Permitted development rights and consumer electrical safety law do not override a lease, a tenancy agreement or a building’s own rules.

The decisive question is usually whether the balcony is demised to you under the lease or forms part of the common parts of the building. A demised balcony gives you a stronger position, though covenants on external alterations and on the appearance of the building may still bite. If the balcony is common parts, you are asking permission to attach equipment to something you do not hold.

Managing agents are advised to weigh lease terms, safety and insurance. Two concerns are singled out: fire and electrical safety in buildings awaiting external wall remediation, and the risk of panels falling from height. Both are reasonable grounds for a refusal, and both are worth addressing directly in any request you make: mounting method, fixings, wind loading, and the fact that the device carries no battery.

Get the answer in writing. An email from a managing agent is worth a great deal more than a verbal nod when an insurer asks a question later.

MCS certification is not required for plug-in solar and is not referenced anywhere in the framework. That removes a cost and a gatekeeper, but it also removes the qualification that export payments depend on.

The Smart Export Guarantee requires MCS certification of the installation together with an export-recording smart meter. Plug-in solar in practice satisfies neither, so it sits outside the SEG. No government document states a legal exclusion, so this is a practical barrier rather than a formal one. The position for a buyer is that you are very unlikely to be paid for what you export. Assess the device on the electricity you avoid buying rather than on income from the grid.

That makes self-consumption the whole economic case, and it is why daytime occupancy and appliance timing matter far more here than they do for a full roof system.

DESNZ commissioned Arceio Limited, with laboratory partner Eurofins E&E UK, to test six commercially available systems through standard 13 A sockets. The report, reference RAF013/2526, was published in June 2026. It is the empirical basis for the whole framework, and its findings are mixed.

The study concluded that plug-in PV “can demonstrate safe and technically coherent behaviour” but that “product quality is not uniform across the market”. Those two clauses belong together. The technology is sound, but individual products vary. That is the argument for buying from a manufacturer that has completed the ENA registration rather than from the cheapest listing you can find.

On 9 June 2026, ECA, Electrical Safety First, the IET, NICEIC and SELECT issued a joint statement urging caution. The professional bodies are not opposed in principle, but they are not celebrating either, and their reservations map closely onto the study’s negative findings.