Green Hydrogen Certification: PPAs, temporal matching and ISCC EU 2025

Introduction

Green hydrogen represents one of the most promising solutions for industrial decarbonization, but obtaining Green Hydrogen Certification as a renewable fuel (RFNBO) in the European Union requires much more than a simple Guarantee of Origin.

With the entry into force of Delegated Regulations (EU) 2023/1184 and 2023/1185 on July 10, 2023, the rules of the game have changed dramatically. Companies producing or using green hydrogen must now demonstrate compliance with stringent criteria on the principle of additionality, temporal matching, and geographical criterion.

This article provides an operational guide to understanding how renewable hydrogen certification works, what requirements must be met in PPA (Power Purchase Agreement) contracts, and how to prepare for ISCC EU audits.

What is Green Hydrogen and why is certification essential?

Green hydrogen is produced through water electrolysis using exclusively electricity from renewable sources. Unlike grey hydrogen (from natural gas) or blue hydrogen (with CO₂ capture), green hydrogen generates no carbon emissions during production.

However, to be recognized as RFNBO (Renewable Fuel of Non-Biological Origin), and therefore “renewable,” under the RED II and RED III Directives, hydrogen must meet precise requirements.

The role of PPAs in Green Hydrogen Certification

Power Purchase Agreements (PPAs) are long-term electricity supply contracts between a renewable energy producer and a purchaser. In the context of green hydrogen, PPAs have taken on a central role following the adoption of the 2023 Delegated Regulations.

Characteristics of compliant PPAs for Green Hydrogen

A PPA suitable for RFNBO (green hydrogen) certification must include:

Principle of additionality: the renewable energy used must come from new renewable capacity or non-subsidized installations; the producer must demonstrate that their hydrogen production does not divert green energy already destined for the electricity mix.

Geographic criterion: the renewable source must be connected to the same electricity bidding zone as the electrolyzer or to adjacent zones with negligible congestion, to ensure that hydrogen is produced with genuinely “physical” available energy.

Temporal matching: this is the most relevant aspect for PPAs. Renewable energy production and electrolyzer consumption must coincide in time.

Guarantees of origin and PPAs: Simply purchasing Guarantees of Origin is no longer sufficient: a direct PPA contract with a compliant renewable installation is required. Digital GOs (Guarantees of Origin) remain important as “proof of title” of origin, but must be combined with additionality and temporality requirements.

Temporary exceptions: for installations in areas with over 90% renewables in the electricity mix or in case of direct physical connection to a renewable installation (off-grid), some matching criteria can be simplified.

Without compliant certification, hydrogen cannot access European incentives nor be counted toward companies’ decarbonization targets.

Temporal criterion: the 2030 challenge

The most innovative and demanding criterion introduced by the Delegated Regulations concerns temporal matching between renewable energy production and electrolyzer consumption.

Transitional phase (until December 31, 2029)

During this period, monthly matching is permitted: the operator must demonstrate that, on a monthly basis, the volume of renewable energy covered by the PPA is at least equal to the electrolyzer’s consumption.

This means: 

• Monitoring monthly contracted renewable production

• Monthly verification of electrolyzer consumption

• Documentation demonstrating coverage of needs

Definitive phase (from January 1, 2030)

From 2030, hourly matching becomes mandatory: renewable energy production and electrolyzer consumption must coincide hour by hour.

This requirement demands:

• Real-time measurement systems with hourly granularity
• Advanced smart metering on renewable installation and electrolyzer
• Digital traceability platforms (blockchain, electronic registries)
• Guarantees of Origin with hourly timestamps

The transition to hourly matching represents a significant technical and organizational challenge, especially for installations powered by intermittent sources like solar and wind. Many companies are already investing in electrical storage systems to ensure operational continuity.

Why guarantees of origin are no longer sufficient

Before July 10, 2023, many operators considered using Guarantees of Origin sufficient as a tool to demonstrate green hydrogen certification. The Delegated Regulations definitively clarified that GOs alone are no longer acceptable as sole proof; they remain valid only as supporting evidence within a compliant and tracked PPA.

With the adoption of Delegated Regulations (EU) 2023/1184 and 2023/1185, published in the Official Journal of the EU on June 20, 2023 and entered into force on July 10, 2023, the Commission clarified that to classify hydrogen as RFNBO, all cumulative requirements must be met:

• Additionality: contractual connection with a specific renewable installation or non-subsidized installation.

• Geographic criterion: the renewable installation must be located in the same market zone as the electrolyzer. Adjacent zones are permitted only if no significant grid congestion exists.

• Temporal criterion: temporal correlation between production and consumption (monthly matching until December 31, 2029, hourly matching from January 1, 2030).

ISCC EU Certification for Green Hydrogen

ISCC EU is one of the voluntary schemes recognized by the European Commission to demonstrate compliance with RED II/RED III requirements. The scheme has integrated into its technical documents (ISCC EU 201-204) all specific criteria for renewable hydrogen.

Requirements verified in ISCC EU audits

During an ISCC certification audit, the inspection body verifies:

• Contractual Documentation PPA
  1. Contracts with clauses demonstrating additionality and location
  2. Certificates of commissioning for renewable installations
  3. Documentation on absence of incompatible subsidies

• Geographic Compliance Electricity
  1. Grid maps demonstrating installation locations
  2. Grid operator (TSO/DSO) attestations on market zone
  3. Network congestion analysis for adjacent zones

• Production and Consumption
  1. Data Monthly reports (until 2029) or hourly (from 2030) of renewable production
  2. Electrolyzer consumption data with timestamps
  3. Documented correlation between the two flows

• Guarantees of Origin
  1. GOs as supporting documentation to the PPA
  2. Verification of volumetric and temporal correspondence
  3. Cancellation of GOs in the appropriate national registry

• GHG Emissions Calculation
  1. Calculation methodology compliant with RED II/RED III
  2. Calculation files with documented emission factors
  3. Well-to-gate emissions of produced hydrogen

• Mass Balance System
  All certified hydrogen must be accounted for in an ISCC mass balance system.
  1. Inputs (renewable energy) and outputs (hydrogen) must be consistent
  2. Each delivery of certified hydrogen must be accompanied by an ISCC Sustainability Declaration.

Proper preparation for ISCC EU audits: operational checklist

To successfully pass an ISCC EU audit, companies must:

• Implement a robust document management system
• Install certified and calibrated measurement systems
• Train personnel on regulatory requirements
• Maintain an updated database of all contracts and certificates
• Conduct preliminary internal audits to identify gaps
• Designate an RFNBO compliance officer

Regulatory timeline for Green Hydrogen Certification: from uncertainty to clarity

Tangible market benefits for Green Hydrogen producers

Incentives

RFNBO-certified hydrogen can benefit from subsidies and financing under the REPowerEU package and innovation funds, as well as being sold at higher prices than grey hydrogen, reflecting its environmental value.

Market positioning

Companies that certify early build a reputation for technological leadership that will facilitate strategic partnerships with large industrial users (steel, chemicals, refineries). Acquiring expertise through process optimization will allow companies to benefit from a competitive and lasting asset when the hydrogen market reaches maturity.

Contribution to ESG Objectives

The use of RFNBO-certified hydrogen allows for concrete reduction of Scope 1 and 2 emissions, thus contributing to corporate ESG objectives and cost of capital.

What it takes to certify Green Hydrogen: operational challenges

Infrastructure investments

Advanced measurement systems, smart metering, digital traceability platforms, and in many cases, energy storage systems are necessary.

Contractual complexity

PPAs must be structured with specific clauses that guarantee long-term regulatory compliance.

Certification costs

ISCC EU audits and certification maintenance involve annual costs, varying according to installation size, that must be planned.

Hourly matching management

From 2030, hourly correlation will require much more sophisticated operational systems and continuous coordination between renewable production and electrolysis.

Those who invest in compliance during the monthly matching transitional phase (2025-2029) arrive prepared for the more stringent 2030 obligations, avoiding the last-minute rush when suppliers, auditors, and PPA contracts will be scarce and expensive.

Frequently asked questions on Green Hydrogen Certification

1. Can I use renewable energy from the grid to produce certified hydrogen?

Yes, but with limitations. If the electrolyzer draws energy from the public grid, it must still demonstrate through a PPA that the renewable energy used meets the criteria of additionality, geographical proximity, and temporal matching. The simple presence of renewable energy in the national electricity mix is not sufficient.

2. What happens if my renewable installation doesn’t produce enough energy in a given month?

During the monthly matching period (until 2029), it’s possible to compensate monthly deficits with surpluses from other months, provided the annual balance is positive. From 2030, with hourly matching, storage systems or contracts with multiple renewable installations will be necessary to ensure continuous coverage.

3. Can existing renewable installations be used for compliant PPAs?

Yes, but they must satisfy the additionality criterion. An existing installation can be used if it doesn’t receive public subsidies that already guarantee its profitability, or if it’s located in a zone with over 90% renewable energy in the electricity mix.

4. How much does ISCC EU certification for green hydrogen cost?

Costs vary based on installation size and supply chain complexity. They generally include: initial audit, annual surveillance audits, ISCC fees (variable based on volumes), and consulting costs for preparation. The investment should be evaluated against the economic benefits of certification. Request a consultation for a detailed overview.

5. Do Guarantees of Origin still have a role in certification?

Yes, but secondary. GOs remain a traceability tool and documentary proof of the renewable origin of energy, but they must always be accompanied by a compliant PPA and demonstration of additionality and temporal matching. They can no longer be used as the sole certification instrument.

6. Must ISCC EU certification be repeated every year?

Yes. ISCC EU certification requires an initial audit to obtain the certificate and subsequent annual surveillance audits to maintain validity. This ensures continuous compliance with requirements and production traceability.

7. What happens if I don’t meet temporal matching requirements?

Hydrogen produced during periods when temporal matching is not demonstrated cannot be certified as RFNBO. This means it cannot benefit from incentives, cannot be sold as certified green hydrogen, and will not contribute to corporate decarbonization targets.

Prometheus supports companies in Green Hydrogen Certification

The regulatory and technical complexity of RFNBO certification requires specialized expertise that few companies possess internally. Prometheus offers an end-to-end service that accompanies green hydrogen producers through every phase of the process.

Don’t wait until 2030

Green hydrogen certification as RFNBO is not just a bureaucratic requirement, but a strategic opportunity to position yourself in the energy market of the future, a sector destined to grow exponentially in the coming years.

Contact Prometheus today and discover how to certify your green hydrogen while meeting all requirements.