Plug-in Solar Device Interim Product Specification version 2 published

The Secretary of State published version 2 of the Plug-in Solar Device Interim Product Specification on 16 July 2026¹. The same instrument, the Plugs and Sockets etc. (Safety) Regulations 1994 and Electricity Safety, Quality and Continuity Regulations 2002 (Amendment) Regulations 2026, was made on 16 July 2026, laid before Parliament on 17 July 2026 and comes into force on 27 August 2026². Regulations 1 and 2 extend to England and Wales, Scotland and Northern Ireland; regulation 3 extends to England and Wales and Scotland².

The regulations amend regulation 8 of the Plugs and Sockets etc. (Safety) Regulations 1994 so that a type of standard plug intended for use with a plug-in microgenerator may be approved by a notified body¹. Approval depends on four conditions: the plugs do not conform to BS 1363 because that standard prohibits or restricts using the plug to connect an electricity-generating device to a socket-outlet; except for that prohibition or restriction they do conform to BS 1363; they comply with the Plug-in Solar Device Interim Product Specification; and sample inspection or testing gives reasonable expectation that normal production will match the samples¹.

The regulations define a plug-in microgenerator as a source of energy that generates electricity from the direct conversion of sunlight into electricity, has a maximum rated alternating current output not exceeding 800 watts, is intended for connection to a low voltage consumer's installation by means of a standard plug and socket, is designed to operate in parallel with a distributor's network, and is not designed to import electrical energy from a low voltage consumer's installation for the purpose of storing energy for later supply, other than for control or auxiliary functions permitted by the specification¹. The Electricity Safety, Quality and Continuity Regulations 2002 were amended to insert the same definitions into regulation 1(5)².

"The effect of the amendment is that where the source of energy is a plug-in microgenerator, it must not be installed or operated unless it complies with the Plug-in Solar Device Interim Product Specification."

Why it matters for households

The change creates a route for a plug-in solar device, up to 800 watts of rated alternating current output, to be connected to a home's wiring through an ordinary plug and socket rather than a fixed installation¹. Until now BS 1363 contained a provision prohibiting or restricting the use of a plug for connecting an electricity-generating device to a socket-outlet, which is why the regulations create a separate approval route for plugs that comply with the interim specification¹. For a household, that means a device meeting the specification can generate electricity in parallel with the distributor's network without the plug itself being non-compliant¹. The definition excludes devices designed to import energy from the home's installation for storage and later supply, apart from control or auxiliary functions the specification permits, so a plug-in solar device under this route is a generating device rather than a storage device¹. How plug-in solar compares with professionally installed systems is set out in plug-in solar vs professionally installed solar, and the components involved are covered in Plug In Solar: Kits, Components and the UK Offer.

What happens next

The regulations come into force on 27 August 2026². The specification itself, version 2, was published on 16 July 2026¹. No further dates are given in the regulations. The text of version 2 has not been reported in the sources, and no list of compliant products or notified bodies has been reported.

Sources3 cited

1. The Plugs and Sockets etc. (Safety) Regulations 1994 and Electricity Safety, Quality and Continuity Regulations 2002 (Amendment) Regulations 2026, legislation.gov.uk
2. The Plugs and Sockets etc. (Safety) Regulations 1994 and Electricity Safety, Quality and Continuity Regulations 2002 (Amendment) Regulations 2026, legislation.gov.uk
3. The Electricity Safety, Quality and Continuity Regulations 2002, legislation.gov.uk