ISO 50100:2026 - Energy-Related GHG Emissions Decarbonization | Wattnow
INTERNATIONAL STANDARD 2026 | ISO/TC 301

ISO 50100:2026 - Decarbonization of Energy-Related Emissions (ERGE)

ISO 50100:2026 - ERGE Decarbonization Requirements Diagram Scope 1 – Direct Emissions • Stationary combustion (gas, oil, biomass) • Mobile combustion (vehicles) • Industrial processes (cement, chemicals) • Refrigerant leaks (AC systems) Mandatory ✓ Scope 2 – Purchased Energy • Electricity (grid / contract) • Industrial steam • District heating / cooling • (Compressed air not included) Mandatory ✓ Scope 3 – Optional • Upstream / downstream purchases • Transport and distribution • Use of sold products • Employee commuting Optional (recommended) Validation (Future Plan) vs Verification (Historical) Validation: Confirmation of the decarbonization plan's plausibility Verification: Confirmation of historical results' accuracy Base year: Consecutive 12-month period (tCO₂e/year) Absolute reduction: Mandatory, not only intensity-based ERGE Calculation (ISO 50100) Activity Data × Emission Factor Activity Data = amount of energy consumed (kWh, L, kg) Emission Factor = kgCO₂e/kWh or equivalent ET = Σ (Qi × Fi) Sources: IPCC, ADEME, IEA, or specific factors

What is ISO 50100?

ISO 50100 - Energy management and decarbonization: a standard that guides organizations in reducing their energy-related CO₂ emissions by integrating energy management into a structured decarbonization system.

Key Technical Point: ISO 50100 introduces the distinction between validation (compliance of the decarbonization plan) and verification (compliance of historical results). It applies to any organization, regardless of sector, and imposes a base year over 12 consecutive months as well as an absolute reduction of emissions.

DEFINITION

ISO 50100 - Energy Management and Decarbonization

ISO 50100:2026 - Energy management systems and energy savings - Decarbonization - Requirements with guidance for use is the first international standard dedicated to the decarbonization of energy-related emissions. It guides organizations in reducing their energy-related CO₂ emissions by integrating energy management into a structured decarbonization system.

The standard applies to any organization, regardless of its sector, size, or geographical location. It is designed to complement existing energy management systems (ISO 50001) or any other system including energy performance objectives.

SCOPE

Scope 1 & Scope 2: Mandatory ERGE Perimeter

ISO 50100 applies to any organization regardless of size, location, or types of energy consumed. The mandatory minimum perimeter covers two categories of emissions:

Scope 1

Direct Emissions

Stationary combustion (gas/oil/biomass boilers), mobile combustion (vehicles, forklifts), industrial process emissions (cement, chemicals), refrigerant leaks. Mandatory

Scope 2

Purchased Energy

Electricity (grid or specific contract), industrial steam, heat, cold. Compressed air is not included in Scope 2. Two approaches: location-based (average grid factor) or market-based (low-carbon supply contracts).

Scope 3

Optional

Purchases, upstream/downstream transport, commuting, use of sold products, end-of-life. ISO 50100 allows voluntary inclusion but does not require it.

CALCULATION METHOD

ERGE Calculation: Activity Data × Emission Factor

Activity Data × Emission Factor
Activity Data = amount of energy consumed (kWh, liters, kg, m³)
Emission Factor = coefficient expressed in kgCO₂e/kWh or equivalent

The complete formula for all energy consumed is:

ET = Σ (Qi × Fi) where:
ET = Total emissions (tCO₂e/year)
Qi = Quantity of energy type i consumed (kWh, L, kg)
Fi = Emission factor for energy type i (kgCO₂e/kWh or equivalent)

Emission factors can come from public sources (IPCC, ADEME, IEA) or be organization-specific (contractual emission factors for electricity, life cycle analyses, etc.).

CONFORMITY & ATTESTATION

Validation (Future Plan) vs Verification (Historical)

ISO 50100 adopts the terminology of ISO/IEC 17029 and introduces two types of declarations:

Validation

Independent review of the decarbonization plan and projections. Confirmation that assumptions are reasonable and the plan can achieve the absolute target. Focuses on the future.

Verification

Checking historical data: actual energy consumption and applied emission factors. Confirmation that declared ERGE are materially correct. Focuses on the past.

Concrete Example: An industrial company has its plan to reduce ERGE (Scope 1+2) by 35% by 2030, with a 2025 base year, validated. Each year, it has its actual emissions verified by an accredited third-party body.

CARBON METROLOGY

Base Year, Intermediate Targets, and Absolute Reduction

ISO 50100 imposes a base year over a consecutive 12-month period. This base year serves as the benchmark for all future reductions. The main quantities defined by the standard are:

EBT : Total emissions for the reference year (tCO₂e/year)
EBS1 / EBS2 : Scope 1 and Scope 2 emissions for the reference year
EAT / ELAT : Intermediate (EAT) and long-term (ELAT) absolute reduction targets
EMT : Monitored emissions at a given date, compared to targets

Absolute Reduction Requirement: An intensity reduction (per ton produced, per m², per employee) is not sufficient unless accompanied by an absolute decrease in emissions. A company that reduces its carbon intensity by 20% but increases production by 30% will see its absolute ERGE increase: this would not comply with ISO 50100.

TECHNICAL ABBREVIATIONS

ISO 50100 Glossary of Acronyms

AcronymMeaning
ERGEEnergy-Related GHG Emissions
EnMSEnergy Management System
GHGGreenhouse Gas
tCO₂eTonne of CO₂ equivalent (integrates GWP of different GHGs)
FiEmission factor for energy type i
QiQuantity of energy type i consumed (kWh, L, kg)
NORMATIVE COMPLEMENTARITY

ISO 50100, ISO 50001, ISO 14064-1: Distinct Roles and Synergies

ISO 50100 is not an autonomous management system. It is designed as a strategic overlay. Annex A of the standard details the interfaces with ISO 50001:2018.

ISO 50001 - Energy Efficiency

Improves energy performance: consumption reduction, EnPI optimization. Does not directly quantify emissions.

ISO 14064-1: GHG Quantification

Provides carbon accounting principles: perimeters, emission factors, uncertainty management.

ISO 50100 - ERGE Decarbonization

Adds the mandatory absolute reduction, the temporal trajectory, and the validation/verification distinction.

WATTNOW TECHNICAL SOLUTION

ERGE Monitoring Platform Compliant with ISO 50100

Our IoT solution continuously calculates your energy-related emissions, establishes the base year, and tracks your intermediate targets (EAT, ELAT).

Automated Collection

Hourly readings from meters (electricity, gas, steam, oil) and dynamic emission factors (Fi).

Baseline & Targets

Calculation of EBS1, EBS2, EBT. Visualization of gaps between EM and EAT. Alerts for deviations.

Validation/Verification Reporting

Export of historical data and projections for certification bodies.

TECHNICAL FAQ

Frequently Asked Questions about ISO 50100

What is ISO 50100?

ISO 50100 — Energy management and decarbonization: a standard that guides organizations in reducing their energy-related CO₂ emissions by integrating energy management into a structured decarbonization system.
What is the ERGE calculation method?

The calculation follows the formula: Activity Data × Emission Factor. i.e., ET = Σ (Qi × Fi).
What is the mandatory scope of ISO 50100?

Scope 1 (direct emissions) and Scope 2 (indirect emissions from purchased energy). Compressed air is not included in Scope 2. Scope 3 is optional.
Does ISO 50100 require absolute or intensity-based reduction?

An absolute reduction of ERGE, expressed in tCO₂e/year. An intensity reduction is only accepted if accompanied by an absolute decrease.
Does ISO 50100 replace ISO 50001?

No, they are complementary. Annex A of the standard details their articulation.

Anticipate ISO 50100 Now

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