Direct answer: Plug-in solar has its own legal definition, an 800W ceiling, a product specification every kit must meet and a plug-approval route around BS 1363. Here is what the regulations and network guidance actually say.
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The Rules for Plug-in Solar in the UK: the Interim Product Specification, the 800W Limit and G98
Plug-in solar is not rooftop solar with a shorter cable. Since 2026 it has been its own class of device in UK law, with a definition, a product specification and a compliance route that no other kind of solar shares. The documents are public, and they are short on ambiguity.
A device class defined in law
The Plugs and Sockets etc. (Safety) Regulations 1994 and Electricity Safety, Quality and Continuity Regulations 2002 (Amendment) Regulations 2026 were made on 16 July 2026 and came into force on 27 August 2026. They create the legal category of "plug-in microgenerator": a source of energy that
- generates electricity from the direct conversion of sunlight;
- has a maximum rated alternating current output not exceeding 800 watts;
- is intended to connect to a low-voltage consumer's installation by means of a standard plug and socket;
- is designed to operate in parallel with the distributor's network; and
- is not designed to import electricity from the installation for storage, other than control or auxiliary functions the specification permits.
Those five conditions are the legal boundary of plug-in solar in Great Britain. The 800W ceiling is not a market convention or a manufacturer's choice — it is part of what the device is.
The specification every kit must meet
The same regulations changed the Electricity Safety, Quality and Continuity Regulations 2002 so that a plug-in microgenerator must not be installed or operated unless it complies with the Plug-in Solar Device Interim Product Specification — version 2, published by the Secretary of State on 16 July 2026 and available on GOV.UK alongside the consultation material.
That document is the practical compliance test. It is what a kit must be built and tested against. Where a generating source that forms part of a consumer's installation would otherwise have to comply with British Standard Requirements, the amended regulations send plug-in microgenerators down the specification route instead.
The plug question
BS 1363 — the standard behind the familiar three-pin plug — contains a provision that prohibits or restricts using a standard plug to connect an electricity-generating device to a socket-outlet. Plug-in solar runs straight into that rule, because a generating device on a 13A plug is exactly what it is.
The 2026 regulations resolve the conflict rather than working around it. They allow a notified body to approve a standard plug type intended for use with a plug-in microgenerator if three conditions hold: that it does not conform to BS 1363 solely because of the prohibition clause; that it conforms to BS 1363 in every other respect; and that it complies with the interim product specification. The plug on a compliant kit is therefore an approved plug under an amended standard — not a gap in the rules.
Notifying your network operator (G98)
Grid connection for small generation is governed by the Energy Networks Association's Engineering Recommendation G98, which covers fully type tested micro-generators up to and including 16A per phase — in practice, anything under 3.68kW per phase. Above that capacity the heavier G99 process applies instead.
G98 is a notification rather than an application. Once a compliant, type-tested kit is commissioned, the owner or installer informs the distribution network operator and supplies the required commissioning information. National Grid's guidance for the single-premises process states the deadline plainly: notify the DNO within 28 days of commissioning. Compliance remains the owner's responsibility — the equipment must be able to demonstrate that it meets the requirements — and for G98-class equipment, manufacturers are required to lodge declarations of compliance in the ENA register.
Check a device against the register
The ENA's Connect Direct device database lets you search compliant devices by type and status. It is the quickest public way to check whether a particular inverter or kit has been through the compliance process.
What the rules do not cover
The regulations define the device, its plug and its compliance route. They do not promise savings — the government's modelled figures are set out in our breakdown of the impact assessment — and they do not replace checks on your own installation, which our buying guide covers in full.
Sources and limits
- The Plugs and Sockets etc. (Safety) Regulations 1994 and Electricity Safety, Quality and Continuity Regulations 2002 (Amendment) Regulations 2026 (SI 2026/848; made 16 July 2026, in force 27 August 2026)
- Plug-in Solar Device Interim Product Specification, version 2
- GOV.UK: Plug-in solar consultation and outcome
- ENA: Connecting generation to the electricity networks
- National Grid: Micro-generation single (G98)
This page summarises the published documents; it is not legal advice, and requirements can change as the specification moves through its interim stage.