SECR and ESG reporting: how solar evidence actually fits in

A finance director signs off a solar installation. The panels go up. Six months later, someone in sustainability gets asked to “just add the solar numbers” to the SECR disclosure.

That request is where many otherwise sound projects come unstuck. The panels work fine. The real problem is planning. Nobody decided, up front, what evidence the generation needed to produce — or which report it needed to support.

This isn’t a compliance technicality. SECR is a binding legal requirement with a specific format. Above it sit the ESG frameworks that investors, lenders and increasingly regulators actually read.

Getting the evidence right matters. It’s the difference between a line item that survives audit and one that gets quietly removed the year someone asks a hard question about it.

What SECR actually requires

The Companies (Directors’ Report) and Limited Liability Partnerships (Energy and Carbon Report) Regulations 2018 introduced the Streamlined Energy and Carbon Reporting (SECR) framework, effective for financial years starting on or after 1 April 2019. It’s not voluntary for the organisations it covers. It isn’t the same thing as a general ESG statement, either — it’s a specific set of disclosures required in the directors’ report.

You’re in scope if your company or LLP is quoted, or if it’s “large”. “Large” means meeting at least two of: turnover above £36 million, balance sheet total above £18 million, or more than 250 employees. Where you meet those thresholds, the official Environmental Reporting Guidelines require you to disclose, each year:

• UK energy use — at minimum, electricity, gas and transport fuel
• Associated greenhouse gas emissions (Scope 1 and Scope 2, as a minimum)
• At least one intensity ratio, so a reader can compare emissions against a business metric such as revenue or floor area, not just an absolute total
• A narrative on the energy efficiency actions taken during the year

Organisations using 40 MWh or less of energy a year can claim the low-energy-user exemption. But they still have to state that they’re claiming it, rather than simply omitting the disclosure. There’s no threshold at which a company in scope can just leave the section blank.

Two developments make 2026 a genuinely different year to get this right. First, the Department for Business and Trade published the final UK Sustainability Reporting Standards — UK SRS S1 and S2 — on 25 February 2026. These adapt the ISSB’s global IFRS S1/S2 standards for UK use.

Second, in its response to the consultation that produced them, government committed to review how SECR interacts with UK SRS “with a view to reducing unnecessary duplication.” That’s a review commitment, not a confirmed phase-out date. As a result, SECR’s specific disclosure format still stands, and shouldn’t be treated as already redundant. If you’re in scope for SECR this year, report it properly — watch for government to clarify the interaction, but don’t assume the outcome now.

How on-site generation should actually be evidenced

The mistake we see most often isn’t a fabricated number — it’s an unsupported one. A generation figure quoted from a supplier’s brochure, or a rough annual estimate, doesn’t survive an auditor or an investor’s due-diligence team asking “show me.” You build a defensible figure from a specific evidence chain. Set that chain up before you switch the panels on, not after the first report falls due.

Evidence tier	What it establishes	Where it comes from
MCS commissioning certificate	Links a specific system, at a specific address, to a stated capacity	Your installer, on handover
Half-hourly metered generation data	The actual output over time, not a modelled estimate	Inverter monitoring platform or smart meter
Renewable Energy Guarantees of Origin (REGO)	One certificate issued per MWh of renewable output, administered by Ofgem	Ofgem’s REGO register, tied to your metered generation
Self-consumption vs export split	What was actually used on site (offsetting grid draw) versus sold back	Your metering and, where applicable, Smart Export Guarantee records

Metered data beats a modelled estimate every time someone challenges a reporting figure. An MCS certificate plus your own meter readings gives you a stronger position than relying on an installer’s projected annual yield.

Solar often sits alongside a green tariff or purchased renewable certificates elsewhere in your energy mix. When it does, keep the two clearly separated in your reporting. On-site generation you can evidence physically is a different, stronger claim than a certificate bought to cover grid-supplied power — and conflating them is exactly what a sustainability auditor learns to spot.

The mistake: solar as the whole answer

Solar is visible, it’s popular with staff and customers, and it produces a genuinely good number for a report. That combination is precisely why it gets over-claimed. We regularly see one of two versions of the same error:

• Solar presented as “our net-zero plan” rather than one measure among several — with no parallel evidence of efficiency improvements, procurement changes or demand reduction to back up a broader decarbonisation narrative.
• Generation output confused with genuine carbon reduction, without adjusting for the fact that most commercial arrays only offset a portion of total consumption — the rest still comes from the grid, at the grid’s carbon intensity that year.

A single rooftop array, however well specified, is one lever. The SECR “energy efficiency actions” narrative expects a portfolio of measures, and so does any credible ESG statement — generation, but also efficiency retrofits, controls and metering improvements, and procurement decisions. State each one’s contribution separately and honestly.

A report that leans entirely on one solar figure invites trouble. Without a clear efficiency and procurement story alongside it, a board or investor tends to ask one question. It’s the question that unravels an overstated claim: “what else have you actually done?”

Where this connects to the ESG frameworks that matter

SECR is a UK statutory floor. Above it sit the frameworks a board or an institutional investor actually cares about. They ask for the same underlying evidence, just in a different — usually more demanding — shape:

• UK SRS S1 and S2 — the newly published UK adaptation of the ISSB’s global sustainability and climate disclosure standards, expected to become mandatory for around 500 listed companies from 1 January 2027 under proposals the FCA is consulting on, per ICAEW’s summary of the publication. S2 in particular expects Scope 1, 2 and material Scope 3 emissions, not just the Scope 1/2 minimum SECR sets.
• Investor and lender due diligence — banks and institutional investors increasingly ask for the same energy and carbon data as part of financing terms, and they ask the same “show me the metering” question an auditor would.
• Customer and supply-chain requirements — larger customers increasingly push Scope 3 reporting requirements down their supply chain, meaning your generation and consumption evidence may end up feeding someone else’s disclosure, not just your own.

The practical implication is straightforward: build the evidence chain once, to the highest standard any of these frameworks will ask for. Don’t produce a rough SECR figure this year and then scramble to substantiate it properly when UK SRS or an investor’s due-diligence team comes asking. Metered data, an MCS certificate, and REGOs held against your own generation clear that bar. That holds true regardless of which framework is reading it.

Getting solar’s contribution right, before the report is due

None of this is a reason to avoid solar. It’s a reason to plan its evidence and its place in the wider story from the outset. Don’t retrofit a narrative once the panels are already on the roof.

That’s exactly what sits inside our net-zero strategy service: placing on-site generation honestly alongside efficiency, storage and procurement. It also means producing the carbon and cost evidence in a form your finance and sustainability teams can defend. That evidence needs to hold up under SECR today, and under UK SRS or investor scrutiny tomorrow.

Sources: legislation.gov.uk — Companies (Directors’ Report) and LLPs (Energy and Carbon Report) Regulations 2018; GOV.UK — Environmental Reporting Guidelines, including SECR; GOV.UK — UK SRS S2: Climate-related Disclosures; ICAEW — Government publishes UK Sustainability Reporting Standards; Ofgem — Renewable Energy Guarantees of Origin (REGO).