Plug-in solar is now legal to use in Great Britain. SI 2026/848 came into force on 27 August 2026 and Ofgem has approved the G98 connection changes — only kits listed on the ENA Type Test Register may be used, and Northern Ireland is not covered. Read the UK legal status

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Regulation

Engineers' plug-in solar safety concerns remain

A month after plug-in solar became legal to use in Great Britain, the Institution of Engineering and Technology says two concerns it raised were never resolved. The government says its testing found the kits safe. Here is what each side says, and what you can do.

Written and edited by Christopher Panteli

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Christopher is the founder and editor of MyPlugInSolar. He oversees the site’s research standards, data tools and editorial process. He is not an electrician or solar installer, and specialist technical claims are sourced from official documentation or reviewed by appropriately qualified professionals.

At a glance

  • The Institution of Engineering and Technology (IET) told New Scientist on 17 September 2026 that concerns it raised about residual current devices (RCDs) and islanding were not addressed before plug-in solar became legal, and advises an electrical inspection first.
  • The Department for Energy Security and Net Zero (DESNZ) told the magazine that an independent contractor tested plug-in solar devices on UK house wiring and found them safe.
  • The government’s July 2026 response tightened the rules: a compliant kit may leak no more than 5 mA of smooth DC into the mains, and further tests on older type AC protective devices are under way.
  • Practical steps: buy a kit listed as compliant on the ENA Type Test Register, test your RCD while the kit is generating, plug straight into a wall socket, and have an old or unlabelled fuse box checked first.

Plug-in solar has been legal to use in Great Britain since 27 August 2026. On 17 September, New Scientist reported that the Institution of Engineering and Technology (IET), the engineering body behind the IET Wiring Regulations (BS 7671), believes two safety concerns it raised with the government were not dealt with first. Mark Coles, its head of technical regulations, told the magazine the change had been “rushed”.

The two concerns

RCDs. A residual current device in your consumer unit cuts the power within milliseconds when it senses current leaking to earth. The IET says most RCDs in UK homes were not designed for circuits where power can flow in both directions, and could malfunction with plug-in solar. A related worry, raised in the consultation, is that DC current leaking from electronic equipment can make older RCDs less sensitive.

Islanding. When the grid goes down, a plug-in kit must switch itself off so it cannot keep a circuit live. The IET’s concern is that several kits in one area could, in theory, fool each other into thinking the grid is still on, putting people repairing the network at risk. See anti-islanding explained.

What the government says

A DESNZ spokesperson told New Scientist that an independent contractor had fully tested plug-in solar devices on UK house wiring and found them safe, and that tests with older household protective devices found no evidence their protection was affected. Coles replied that those tests used kits bought outside the UK, because none was legal here at the time, and new RCDs.

The government’s consultation response of July 2026 deals with the RCD point. It says DC leakage that can reduce the effectiveness of older, mostly type AC, RCDs is not unique to plug-in solar, because many modern power supplies leak small amounts of DC. In response it amended the Interim Product Specification so that a kit’s smooth DC leakage into the mains must not exceed 5 mA, and it is running further tests on older type AC protective devices, after which that limit will be reviewed. The specification also sets anti-islanding requirements every compliant kit must meet.

The specification is described as interim: the government says longer-term changes to standards, including the wiring regulations, are being considered separately. The disagreement is about whether the interim rules go far enough in the meantime.

What it means for you

  • Buy a kit listed as compliant on the ENA Type Test Register. Compliant kits have been assessed against the specification, including the DC leakage and anti-islanding rules. See every kit the register lists.
  • Test your RCD with the kit running. The specification tells manufacturers to instruct you to press the test button on your RCD or RCBO while the kit is producing power, and to call an electrician if it does not trip straight away.
  • Look at your fuse box first. If it has old rewireable fuses, is not labelled, or you do not know its condition, the specification says to have it inspected by a qualified electrician before you install a kit.
  • Plug straight into a wall socket, never an extension lead, multi-way adaptor or RCD adaptor.

For the detail on RCD types and DC leakage, read RCDs, DC leakage and plug-in solar.

Sources

  1. 1. Plug-in solar panels still have safety risks in the UK despite legalisation — New Scientist, 17 September 2026
  2. 2. Plug-in solar: regulatory amendment and interim product specification — government response — Department for Energy Security and Net Zero, 16 July 2026
  3. 3. Plug-in Solar Device Interim Product Specification, version 2.0 — Department for Energy Security and Net Zero, 16 July 2026

Read the full guide

Where the UK rules stand

Plug-in solar has been legal to use in Great Britain since 27 August 2026, when SI 2026/848 came into force alongside Ofgem-approved changes to the G98 connection code — provided the kit is listed as compliant on the ENA Type Test Register. Northern Ireland is not covered. See the current legal status and our editorial policy.

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