Source documents
The primary documents behind our plug-in solar guidance, with the date we retrieved each one and a hash you can check our copy against.
Government documents move. Asset URLs change, publications are withdrawn and replaced, and a citation that worked last month returns a 404 this month. That is not hypothetical here: version 1 of the plug-in solar specification was withdrawn and replaced within weeks of publication.
So where a claim on this site rests on a government publication, we keep a copy of the version we read, record the date we retrieved it, and publish a hash so you can confirm our copy has not been altered.
Legislation is the exception. We do not mirror legislation.gov.uk, because it
serves the text as made and as amended at any date, and a frozen copy could
only ever show one moment — which would eventually make our archive wrong in
exactly the way this archive exists to prevent.
SI 2026/848
The Plugs and Sockets etc. (Safety) Regulations 1994 and Electricity Safety, Quality and Continuity Regulations 2002 (Amendment) Regulations 2026
Not mirrored deliberately. legislation.gov.uk serves both the "as made" text and the text as amended at any date, and its URLs are permanent. A static copy here could only ever show one moment, and would quietly become wrong if the instrument is amended.
Not archived by design — see the note above.
IPS v2
Plug-in Solar Device Interim Product Specification, version 2
The document a kit must comply with for its plug to be lawful under SI 2026/848. It is where the one-device-per-circuit labelling requirement lives — but read it with the government response, which makes that allowance conditional on an amendment to G98.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 681 KB) →
SHA-256
sha256-AD3lWgwXOFEq8Y592Dul/grXE6ILm9E1S/e/VMjo9U4=
IPS v1 Withdrawn
Plug-in Solar Device Interim Product Specification, version 1
Withdrawn and replaced by version 2. Kept because it is the reason this archive exists: a specification published in June was gone by July. Do not rely on it for anything current.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 1411 KB) →
SHA-256
sha256-Gr+EgF5Uop+GNQgClc96ZSfzpd0W0WVADIezAHXzLKE=
Government response
Plug-in solar: government response
Sets out what the government decided and why, including that the IPS applies during a transitional period while longer-term standards are developed. No end date for that period is given. Also the only one of these documents that states the operative device limit: one per household until G98 is amended to allow one per circuit.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 434 KB) →
SHA-256
sha256-PbqxzLRw3Se+W+v7nGUHn20/ePhfDMm1Qt+S2XMGis8=
SEG annual report Y5
Smart Export Guarantee Annual Report — SEG Year 5
The only authoritative free source of SEG tariff rates. Figure 2.1 tabulates untied export tariffs and Figure 2.2 tied ones, with supplier, tariff name, dates, rate and rate type — every tariff offered in the scheme year. Retrospective by nature, so it is our baseline and our record of how rates moved, never a current quote.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 1408 KB) →
SHA-256
sha256-O5jsjpUUS+1hTShIVvvruuXysDwaFOBwcgCePfMdlUE=
TDCV decision 2026
Review of typical domestic consumption values: decision
Sets the typical annual household consumption figures the calculator uses as its default, in force from 1 July 2026. Mirrored because the calculator depends on it: a reader checking our arithmetic in two years needs the version we used, not whichever review has superseded it.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 203 KB) →
SHA-256
sha256-AJ6y6+SXnhaR0ZAK2dBeefZV7q2hgBuMbu0vekmhnsk=
TEEIP guidance
Tenants' energy efficiency improvements provisions: guidance for domestic landlords and tenants
Departmental guidance on Part 2 of the 2015 Regulations — the tenant's right to request consent for an energy efficiency improvement. Published by a department that no longer exists, on the legacy attachment_data asset path, which is about as fragile as a GOV.UK link gets.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 946 KB) →
SHA-256
sha256-TpwLcYYzgAPOVedZXeqHqcMQUlPQ9OibDQjH76ZHvb4=
Ofgem SEG guidance
Smart Export Guarantee: Guidance for Generators
The source for the certification and export-metering conditions on our SEG page. Mirrored because the asset sits on a dated file path and the landing page carries no version or revision metadata — we could not establish which revision this is, only that it is the copy the publisher served on the date shown.
Official version (PDF) → Publisher's page → Our archived copy (PDF, 220 KB) →
SHA-256
sha256-TU7Sql0LYj5fSm3nyFMjnTtz3ZMPUSP8YVWDRQ1+yJw=
Consultation
Plug-in solar: consultation document
The proposals as consulted on. Useful for understanding what changed between proposal and final specification. An accessible HTML version is published alongside the PDF.
Official version (PDF) → Publisher's page → Accessible HTML version → Our archived copy (PDF, 203 KB) →
SHA-256
sha256-QopL2lOtS52cUyabTOtH0hcM4Xkq4RyncL/2msmGKj4=
Verifying a copy
Every archived file shows a SHA-256 in the same form browsers use for subresource integrity. To check that our copy is byte-for-byte what we say it is, download it and run:
openssl dgst -sha256 -binary FILE | openssl base64 -AThe result should match the hash shown against that document. If it does not, tell us — that is a serious problem and we want to know.
Licence and attribution
Contains public sector information licensed under the Open Government Licence v3.0.
We archive these documents so that claims we make remain checkable against the version we made them from. We are not a government body, this is not an official archive, and nothing here is endorsed by any department. Where our copy and the official version differ, the official version governs.
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