Quick summary

ESRS E1 is the climate standard at the heart of EU sustainability reporting, and it turns energy consumption and emissions into audited, disclosed data. This article explains what the standard demands of energy data, why measurement quality is the hard part, and how the 2026 Omnibus reforms reshaped who has to report.

Introduction

For years, corporate climate disclosure was a largely voluntary exercise, judged by ambition more than accuracy. The EU's Corporate Sustainability Reporting Directive changed that, and its climate standard, ESRS E1, is where the change bites hardest. Energy consumption and greenhouse gas emissions are no longer narrative claims; they are disclosed, assured data points sitting inside a regulated report.

That shift turns a sustainability question into a data-quality question. The difficulty for most organisations is not deciding what to say about climate, but producing energy and emissions figures robust enough to withstand assurance. ESRS E1 is, in practice, a measurement standard as much as a reporting one.

What ESRS E1 actually requires

ESRS E1 is the climate-change standard within the broader European Sustainability Reporting Standards. It is structured around a set of disclosure requirements covering transition plans, climate risks, targets, and, centrally, energy consumption and gross greenhouse gas emissions across Scopes 1, 2, and 3.

Two features make it demanding. First, it explicitly covers energy: the standard requires disclosure of total energy consumption and the energy mix, not just headline emissions. Second, its emissions disclosures are designed to be consistent with the Greenhouse Gas Protocol, which means the Scope 2 dual-reporting logic of location-based and market-based figures flows directly into ESRS reporting (EFRAG, 2023).

The standard also operates under a "material by default" presumption for climate, meaning a company that concludes climate change is not material must actively justify that conclusion rather than simply omit the disclosures. In practice this leaves very little room for omission, which is why for almost every in-scope company the energy data behind ESRS E1 must be produced. The implication is that the energy-data burden lands on nearly everyone in scope, regardless of sector.

Takeaway: ESRS E1 requires disclosure of energy consumption, energy mix, and GHG-Protocol-consistent emissions, and is treated as material by almost all reporters.

Why measurement, not intent, is the hard part

The instinctive assumption is that the challenge of climate reporting is strategic. In practice, the binding constraint is data. Producing a defensible figure for total energy consumption across many sites, meters, and energy types is genuinely difficult, especially where metering is patchy or manual.

The problem compounds for Scope 2. Reporting both a location-based and a market-based figure requires not only consumption data but also accurate records of the contractual instruments, such as guarantees of origin or power purchase agreements, that underpin the market-based number. Gaps or inconsistencies in either dataset surface quickly under assurance.

This is why energy reporting is increasingly a systems question rather than a spreadsheet exercise. Accurate, auditable, time-resolved metering is the foundation on which every ESRS E1 energy and Scope 2 disclosure rests, and organisations that lack it find the reporting burden far heavier than expected.

The hardest part of climate reporting is not deciding what to disclose but generating energy data clean enough to be assured, which is fundamentally a measurement and systems problem.

Takeaway: The real ESRS E1 challenge is producing auditable energy and Scope 2 data, which depends on the quality of underlying metering.

How Omnibus reshaped the scope

The CSRD landscape shifted significantly in early 2026. Responding to concerns about reporting burden, the EU adopted the Omnibus I package, which substantially narrowed who must report. The European Commission's own estimate is that the reforms reduce the number of companies in scope by roughly 80 percent compared with the original CSRD perimeter (European Commission, 2025).

Two points matter for organisations trying to plan. First, the scope narrowed but the substance of what in-scope companies must report was largely preserved; ESRS E1 remains the demanding climate standard it was. Second, timelines moved: a "stop-the-clock" directive postponed application waves, and amended standards are expected to apply to later reporting periods than originally set.

The reason this matters is that "out of direct scope" is not the same as "unaffected." Smaller suppliers increasingly receive data requests from larger customers who remain in scope and need value-chain emissions data, so the practical reach of ESRS E1 extends well beyond the companies legally required to file.

Takeaway: Omnibus cut the reporting population by around 80 percent but kept ESRS E1's substance, and value-chain data demands extend its reach beyond direct filers.

Building energy data that holds up

Whether a company reports directly or supplies data to one that does, the underlying requirement is the same: energy and emissions data that can withstand scrutiny. A few principles distinguish robust data foundations from fragile ones.

Reliable ESRS E1 energy data tends to share these characteristics:

• Direct, automated metering rather than estimates or manual readings where possible

• Time-resolved consumption data, increasingly important as Scope 2 accounting moves toward hourly matching

• Clear records linking contractual instruments to the market-based figure they support

• Consistent methodologies and emissions factors, documented well enough to be audited

• Data retained long enough to support year-on-year comparison and assurance

For organisations across Denmark, the Nordics, and the DACH region, where CSRD obligations and customer data requests are both well advanced, the strategic point is that energy data infrastructure built for compliance also serves optimisation. The same granular metering that satisfies an auditor reveals where energy is wasted and where load can be shifted, turning a reporting cost into an operational asset.

Takeaway: Robust, automated, time-resolved energy data serves both ESRS E1 assurance and operational optimisation, so the compliance investment pays twice.

The value-chain reach that survives the scope cut

The most important consequence of the Omnibus reforms for smaller organisations is counterintuitive: being removed from direct scope does not remove the data burden. ESRS E1 requires in-scope companies to report emissions across their value chains, which means a large reporter needs energy and emissions data from its suppliers, many of whom are far below the reporting threshold themselves.

The reforms did introduce safeguards to limit how much information large companies can demand from the smallest suppliers, and a voluntary standard is intended to cap the detail requested. But the underlying dynamic is unchanged: a supplier to a major in-scope customer will be asked for credible energy and emissions data, voluntary standard or not, because the customer cannot complete its own disclosure without it. The reason this matters is that the practical reach of ESRS E1 extends well beyond the list of companies legally obliged to file.

For a smaller supplier, this reframes the question. The choice is not whether to engage with sustainability data but whether to do so reactively, scrambling to answer each customer request, or proactively, with energy data already measured and ready. Those with a solid data foundation can respond credibly and even use it competitively; those without find each request a fresh burden.

Falling out of direct CSRD scope does not mean falling out of the data chain; the requirement simply arrives through a customer rather than a regulator.

Takeaway: Value-chain reporting means many out-of-scope suppliers still face energy-data requests, so the practical reach of ESRS E1 far exceeds the list of filers.

Why assurance raises the bar on data

A defining feature of CSRD reporting is that the disclosures are not merely published; they are subject to assurance. An external assurance provider examines whether the reported figures are supported, and that examination changes what counts as acceptable energy data. Estimates and undocumented assumptions that might once have passed unchallenged become findings.

The reforms kept assurance at the "limited" level rather than escalating to the more demanding "reasonable" standard, which moderates the burden but does not remove it. Even limited assurance requires that energy consumption and emissions figures trace back to credible, documented sources. The implication is that the quality of the underlying metering and record-keeping is no longer an internal matter; it is something a third party will probe.

This is the deeper reason that energy reporting has become a systems question. Producing a figure is easy; producing one that an assurance provider will accept requires measurement that is accurate, methodologies that are consistent and documented, and records retained long enough to support comparison across years. For organisations across the Nordics and DACH region, where assurance practice is maturing quickly, the organisations that invested early in dependable energy data infrastructure are the ones for whom assurance is a formality rather than a scramble.

Takeaway: Mandatory assurance means energy figures must trace to documented, credible sources, raising the bar on metering and record-keeping quality.

Conclusion

ESRS E1 reframed corporate climate reporting from a question of narrative to a question of data. Its demands on energy consumption and emissions disclosure are exacting, and the difficulty for most organisations lies not in strategy but in producing figures clean enough to be assured.

The Omnibus reforms narrowed the field of direct reporters but left the substance of the standard, and the data demands flowing down value chains, firmly in place. The organisations best positioned are those that treat energy measurement as infrastructure: accurate, automated, and granular enough to satisfy an auditor today and to support genuine optimisation tomorrow.

FAQ

What is ESRS E1?

ESRS E1 is the climate-change standard within the European Sustainability Reporting Standards, which companies use to report under the EU's Corporate Sustainability Reporting Directive. It sets disclosure requirements covering transition plans, climate risks, targets, energy consumption and mix, and gross greenhouse gas emissions across Scopes 1, 2, and 3.

Does ESRS E1 require reporting energy use as well as emissions?

Yes. Unlike a narrow emissions standard, ESRS E1 explicitly requires disclosure of total energy consumption and the energy mix, alongside greenhouse gas emissions. Its emissions disclosures are designed to be consistent with the Greenhouse Gas Protocol, which brings the location-based and market-based Scope 2 methods directly into ESRS reporting.

Did the Omnibus reforms remove the obligation to report?

For many companies, yes, in the sense that the in-scope population was cut substantially, with the European Commission estimating a reduction of around 80 percent. However, the substance of ESRS E1 was largely preserved for those still in scope, and many smaller companies still face data requests from larger in-scope customers needing value-chain information.

Why is energy data quality the main challenge?

Because the standard turns energy and emissions into assured, disclosed figures. Producing a defensible number for total energy consumption across many sites and meters, and supporting a market-based Scope 2 figure with proper records of contractual instruments, is difficult where metering is patchy or manual. Reliable, automated, time-resolved measurement is the foundation that makes the reporting feasible.

Sources

• ESRS E1 Climate Change (Delegated Regulation (EU) 2023/2772, Annex) – EFRAG – 2023 – https://www.efrag.org/sites/default/files/media/document/2024-08/ESRS E1 Delegated-act-2023-5303-annex-1_en.pdf

• EFRAG provides technical advice on draft simplified ESRS to the European Commission – EFRAG – 2025 – https://www.efrag.org/en/news-and-calendar/news/efrag-provides-its-technical-advice-on-draft-simplified-esrs-to-the-european-commission

• Omnibus package (sustainability reporting simplification) – European Commission – 2025 – https://finance.ec.europa.eu/news/omnibus-package-2025-04-01_en

• Directive (EU) 2022/2464 (CSRD) – EUR-Lex – 2022 – https://eur-lex.europa.eu/eli/dir/2022/2464/oj