Scope 2 Is Being Rewritten: What the GHG Protocol Revision Means for Your ESRS E1 Numbers

ESRS E1 does not define how to measure a tonne of CO2e. It points at the GHG Protocol and inherits its definitions. That is normally an advantage: one methodology, globally recognised, stable.

It is less of an advantage when the methodology is being rewritten.

The GHG Protocol is currently revising the Scope 2 standard, and the proposals on the table would change what a renewable electricity claim means. For a reporter, the useful question is not who is right about hourly matching. It is narrower and more practical: which of the choices I am making right now are safe to lock in, and which should stay flexible because the rules underneath them are moving?

Why an accounting revision is a reporting problem

ESRS E1 requires both location-based and market-based Scope 2 figures, prepared on a GHG Protocol-consistent basis. Your market-based number is not a measurement in the physical sense - it is the output of a set of rules about which contractual instruments you may apply to which consumption. Change those rules and the same electricity, the same contracts and the same meters produce a different disclosed number.

E1 also remains the most frequently material standard for almost every reporter, and it is the one your transition plan, targets and capex narrative all hang from. A methodology change upstream does not stay upstream.

What is actually on the table

The GHG Protocol ran a 60-day public consultation on Scope 2 from 20 October to 19 December 2025, alongside a parallel consultation on electricity sector consequential accounting. Two proposals drew most of the attention.

Hourly matching. Today, most market-based accounting works on annual volume matching: buy certificates equal to your annual consumption and the arithmetic works. The proposal would require clean electricity purchases to line up with the hours in which power is actually consumed.

Deliverability. The proposal would require that the electricity could plausibly reach your sites - for example, certificates sourced from generators on an electrically linked grid, with market boundaries determined by physical connection rather than by paperwork.

A worked example makes the difference concrete. Take a manufacturer running two shifts, with consumption concentrated between 06:00 and 22:00, buying annual certificates from a solar portfolio several markets away.

• Under today's rules: annual certificate volume matches annual consumption. Market-based Scope 2 approaches zero.
• Under hourly matching: the evening and night hours have no matching generation. A meaningful share of consumption falls back to the residual mix, and the market-based figure rises - potentially a lot.
• Under deliverability: if the generation sits outside an electrically linked grid, those certificates may not qualify at all, regardless of timing.

Same portfolio. Same year. Three very different disclosed numbers.

A set of practicality measures was floated to ease any transition: load profiles as a proxy where hourly data is unavailable, exemption thresholds, a legacy clause for existing contracts, and a phased timeline.

What the consultation feedback showed

Feedback on the proposed new Scope 2 quality criteria, including hourly-based matching, was largely unsupportive. Of 909 respondents, roughly 70% gave little to no support, 22% were in favour and 7% were neutral.

Read that carefully, in both directions.

It tells you there is substantial resistance, concentrated among buyers who have built procurement strategies on annual matching and certificate markets that would be devalued by a temporal or geographic test. It does not tell you the proposals are dead. A consultation is not a vote, and standard setters routinely adopt changes that a majority of respondents disliked - particularly where the objection is cost of transition rather than conceptual soundness.

It is worth understanding both cases honestly, because this is a genuine technical disagreement rather than a settled question.

The case for tighter criteria: annual, location-agnostic matching lets a company report near-zero Scope 2 while consuming fossil-generated power in every hour it operates. That weakens the signal the figure is supposed to carry and can misdirect decarbonisation investment toward cheap certificates rather than additional clean capacity where and when it is needed.

The case against: hourly data is not universally available, granular certificate markets are thin outside a handful of jurisdictions, and a strict test could strand existing long-term contracts signed in good faith under the current rules - penalising exactly the buyers who moved early.

The timeline as it now stands

• Second public consultation: expected later in 2026, covering additional topics including Scope 2 and Scope 3 interactions and purchased steam, heat and cooling.
• ISO harmonisation: work to align GHG Protocol standards with ISO has extended the schedule.
• Joint corporate standard consultation: expected around Q2 2027.
• Publication: originally targeted for 2027, now expected around late 2028.

Then there is an adoption lag on top: even after publication, a new standard has to be referenced by reporting frameworks and adopted in practice.

The blunt implication for reporting: your FY2026 and FY2027 figures are prepared under the existing standard. Nothing here changes what you file in the near term. What it changes is the durability of decisions you make now that will still be live in 2029.

What to lock in, and what to keep flexible

Safe to lock in.

• Meter-level consumption data with timestamps. Whatever happens to the rules, granular consumption data is only ever more useful. If you are replacing metering or energy management systems, buy hourly capability now - it costs little extra and it is the single input every proposed variant needs.
• A clean measurement boundary. Sites, entities, and the treatment of leased and shared facilities. None of this is affected by the Scope 2 debate.
• Residual mix sourcing and documentation. Under any tightening, more of your consumption falls back to residual mix. Knowing where you source those factors, and being able to evidence it, is pure upside.
• Full documentation of certificate attributes. Issue date, generation period, generator location, grid connection, vintage. You may not need all of it today. You cannot retrofit it later.

Keep flexible.

• Long-dated EAC contracts with no temporal or locational attributes. Be cautious about signing multi-year volumes that would fail a deliverability test, or price them with that risk visible.
• Targets whose baselines rest entirely on market-based figures. If a rule change moves your market-based number, a market-based-only target moves with it. Dual-track your target architecture so the location-based trajectory tells a coherent story on its own.
• Public "100% renewable" claims that depend on annual matching. Worth reviewing against the EU's tightening rules on environmental claims as well as against the accounting debate - the reputational exposure may arrive before the accounting change does.

Contracting hygiene for new PPAs and EAC purchases

Three asks that cost nothing today and protect you later:

1. Timestamps. Require hourly generation data or granular certificates where the market supports them, even if you do not use them yet.
2. Grid and market boundary. Document the physical connection between generator and consumption site. If deliverability lands, this is the evidence that decides whether the contract still counts.
3. Legacy and adjustment clauses. Address explicitly what happens if certificates cease to qualify under a revised standard. A legacy clause was among the practicality measures floated; do not assume you will be grandfathered by default.

What to say in your FY2026 and FY2027 disclosures

ESRS expects you to describe your methodology and its limitations. That is an opportunity rather than a burden here.

State the standard version you applied, the matching approach used (annual volume matching, if that is what you do), and the fact that the GHG Protocol Scope 2 revision is in progress with publication expected around late 2028. If you have modelled the effect of hourly matching on your portfolio, saying so - without over-promising an outcome - is a strong signal of control maturity.

What to avoid: implying that your current figures already meet a future standard, or that the revision will not affect you. Neither is knowable yet, and both are the kind of claim that ages badly in a document your auditor will still be reading in three years' time.

FAQ

Do I have to change anything for FY2026? No. FY2026 and FY2027 reporting is prepared under the existing Scope 2 standard. The changes worth making now are about data capture and contracting, not about restating figures.

Are my existing RECs and guarantees of origin worthless? No. They remain valid under current rules. The open question is how instruments without temporal or locational attributes would be treated under a revised standard, and whether a legacy clause would protect existing contracts.

What is deliverability, in one sentence? A requirement that the clean electricity you claim could plausibly have reached your site - typically via an electrically linked grid - rather than being sourced from an unconnected market.

When does the new standard actually apply? Publication of a joint GHG Protocol and ISO corporate standard is currently expected around late 2028, following a consultation around Q2 2027. Application in reporting follows adoption by frameworks and regulators after that.

Does ESRS E1 require hourly matching today? No. ESRS E1 requires location-based and market-based Scope 2 figures on a GHG Protocol-consistent basis. Current GHG Protocol rules permit annual volume matching subject to the existing quality criteria.