Being specific about this matters, because "it is unclear" is not useful and is often a cover for not having looked.
The Plug-in Solar Device Interim Product Specification states that Engineering Recommendation G98 applies to Great Britain only, that Northern Ireland requirements are set out separately under G98/NI, and that "application of this specification to Northern Ireland is subject to further consideration and may require amendment".
Who answers it: the Department for Energy Security and Net Zero, which wrote that sentence about its own document.
Regulation 3 of SI 2026/848, which amends the Electricity Safety, Quality and Continuity Regulations 2002, extends to England and Wales and Scotland only. Northern Ireland has its own electricity safety regime.
Who answers it: the Northern Ireland Executive. The department has now put that in writing rather than leaving it to be inferred, and named the instrument with it.
In Great Britain a householder notifies their distribution network operator within 28 days using a short online form. None of that machinery reaches here. Northern Ireland's connection requirements sit under G98/NI and its network is operated by Northern Ireland Electricity Networks.
Who answers it: NIE Networks, and the body responsible for G98/NI.
A handful of consultation responses asked how the standards would land in Northern Ireland, and whether the Windsor Framework had anything to say about it. The published response notes that those points were made. It goes no further than noting them.
Who answers it: government, and of everything still open on this page it is the least likely to be answered quickly.
The ENA Type Test Register records a Northern Ireland standard version on each device record, alongside the Great Britain one, with separate compliance sections for each. So the register does track Northern Ireland, which is a concrete thing to point at rather than an absence.
If any of these four moves, that is when we will email you.
This is not a mailing list and there is nothing to buy. Three questions on this page are still open. If any of them is answered, whether by the department, by the networks or by a change to the specification, you get one email saying which one and what it now says.