Plug-in Solar UK: The 800 W Rules That Took Effect on 27 August 2026

Until August 2026 there was no lawful route to sell a solar generator in Great Britain that plugs into an ordinary socket. SI 2026/848 — the Plugs and Sockets etc. (Safety) Regulations 1994 and ESQCR 2002 (Amendment) Regulations 2026, made 16 July and in force 27 August 2026 — created one, by allowing a standard plug to be used with a plug-in microgenerator provided the product meets a specification the regulations point at.

That specification is the Plug-in Solar Device Interim Product Specification v2.0 (DESNZ, July 2026), cited throughout this guide as “the specification”. It is interim on purpose: several of its limits have stated review routes, so check a figure before you rely on it commercially.

Two documents sit alongside it and say different things with different force. BS 7671:2018+A4:2026 is named in the specification’s own reference list and governs the fixed installation. Engineering Recommendation G98 governs the connection to the network and applies to Great Britain only.

A complete kit, sold as one product. The specification defines it as at least one PV module, a grid-following inverter, a factory-assembled lead fitted by the manufacturer with a BS 1363 plug, and a mounting system to attach the panel semi-permanently to a surface or the ground.

There is no consumer unit work, no new circuit and no fixed wiring — that is the whole point of it, and it is why the rules that follow are mostly about the existing installation rather than anything being added to it.

Because the inverter follows the grid, it cannot work without one. It does not generate a supply of its own; it locks onto the voltage and frequency already present and injects current in step. Pull the main switch and the device stops.

• 800 VA maximum apparent power supplied to the installation, and 3.5 A maximum current, single phase (specification §4.1).
• 2000 W maximum total PV module DC power. Retained in the final specification but recorded as under review.
• 960 W — above this total module capacity, the manufacturer must advise the customer to consider a professional assessment of their existing electrical installation before installing.
• Up to 4 modules, no more than 2 in series in any string, with open circuit voltage at the inverter inputs not exceeding 120 V DC — because the risk of sustained DC arcing rises with voltage and the user makes these connections themselves.
• A 5 A maximum BS 1362 fuse in a non-rewireable moulded plug with partially insulated pins.
• Any smooth DC residual current the device puts onto the supply must not exceed 5 mA, so it does not impair an upstream RCD.

• No batteries. Plug-in battery systems and battery-integrated plug-in solar are outside the specification’s scope entirely, and the instructions must carry a prominent warning that the device is not intended to be used with battery storage.
• No extension cables, cable reels, multi-way adaptors, RCD adaptors, travel adaptors or plug convertors.
• Socket circuits only. Not a lighting circuit, and not a spur feeding fixed equipment such as a cooker or a boiler.
• No Y-connectors on the DC side — only matching connector pairs from the same product family, supplied by the manufacturer.
• Not on ACM or MCM cladding, HPL cladding, timber cladding or timber balconies, and not on a building subject to external wall remediation works. Not fixed to a wall forming a property boundary between dwellings.

These are product and instruction requirements rather than duties imposed directly on a householder — but they are the conditions under which the device is designed to be safe, and where one is not met, that is where the electrical work is.

The device plugs into a fixed socket-outlet complying with BS 1363-2, and it must not be connected to damaged, degraded or non-compliant socket-outlets. Where the inverter and the socket are both mounted outside, the socket needs an ingress protection rating of IP55 or better.

That combination — panels outside, sockets usually inside, and no extension leads permitted — is why a fixed outdoor socket-outlet is so often the first real piece of electrical work a plug-in solar installation creates.

Only one device is permitted per circuit, so somebody has to be able to identify which sockets share one. Where the consumer unit does not use modern protective devices, is not clearly labelled, or is of unknown condition, the specification says users should seek inspection and assessment by a qualified electrician before installing the product.

Ring final circuits are fine. A small number of consultation respondents argued otherwise, and the government’s published safety study tested plug-in solar in representative UK installations including ring circuits, finding nothing that would prevent safe operation at 800 W on appropriately protected rings.

This is the part being argued about most, and it is easy to get wrong in both directions. Electrical Safety First recommend that circuits intended for use with plug-in solar have at least a Type A, bidirectionally capable RCD, and that homes with Type AC devices should not use plug-in solar without upgrading first. That is genuine, published safety guidance from a credible body.

It is not a legal requirement. Mandating bi-directional residual current protection in the product was put to the government during the consultation and declined for want of evidence, and the government’s stated long-term preference is that industry moves to Type B or F devices.

Both of those are true at once, and there is a second distinction underneath: the RCD type and whether the device is bidirectionally capable are two separate questions that the phrase “Type A bidirectional” runs together. The full answer is on the RCD page.

Notification is mandatory, and it runs both ways — the distribution network operator must be told when a device is connected and when it is disconnected. The product itself has to carry that statement, with a link to how.

But it is connect and notify, not prior approval. The device is installed and commissioned first and the notification follows, within 28 days of commissioning, using the Installation Document at Form B, Appendix 3 of EREC G98. It does not hold anything up.

One detail worth being precise about: the 28-day deadline comes from G98, not from the product specification. The specification makes notification mandatory but sets no time limit of its own.

Loose panels and a micro-inverter bought separately are not a plug-in solar device, however the listing describes them. The specification requires a complete product including “a factory assembled connection line fitted by the manufacturer with a plug designed to BS 1363”. A self-assembled build cannot meet that, cannot be registered on the ENA Type Test Register as a device, and so gets none of the route the regulations created.

It is worth checking what the panel’s own manual says before anyone argues the point. Modules sold loose through national merchants routinely carry manuals with no mention of plugs, sockets, inverters, BS 1363, RCDs, G98 or the network operator anywhere in them — and which open by stating that installation requires professional skills and knowledge and is to be carried out by qualified personnel. Those are documents written for a designed installation under BS 7671 Section 712.

Compliant devices are listed on the ENA Type Test Register, and the specification is explicit that a device merely submitted for registration does not in itself demonstrate compliance. The register moves quickly, so check it on the day rather than relying on a figure in an article.

To be straight about it: nothing legally obliges a householder to involve an electrician. Anyone telling you the law now requires an assessment is wrong. But the documents themselves keep pointing people at one, and these are the situations where that is worth acting on.

• Kits above 960 W of module capacity — the manufacturer is required to advise you to consider a professional assessment.
• An older, unlabelled or unknown consumer unit — the specification says to seek inspection and assessment by a qualified electrician first.
• A Type AC RCD, or a device you cannot confirm is bidirectionally capable — see the RCD page.
• No suitable outdoor socket — fitting one is electrical work on the fixed installation and carries its own certification.
• A flat, a block, or rented property — the surface restrictions are decided by the building, and permission sits with the freeholder or managing agent.

There is also a recurring one that almost nobody mentions. The specification requires the customer to be told to press the RCD or RCBO test button periodically while the device is generating, because DC leakage from solar, EV chargers and IT equipment together can desensitise an older device — and that if it does not trip immediately, to contact a competent professional electrician about replacing it.