Introduction
On 2 July 2025, the Greek Parliament passed Law 5251/2025, the country’s first dedicated hydrogen law, establishing inter alia a comprehensive framework for the production, certification and regulation of renewable (green) hydrogen (the Law). The Law partially transposes the relevant EU Directive 2024/1788 and aligns with the EU’s Delegated Regulation 2023/1184 on renewable hydrogen certification.
This marks a major step in Greece’s energy transition, further aligning the national framework with the European Green Deal, REPowerEU and the EU Hydrogen Strategy while reinforcing the implementation of the updated National Energy and Climate Plan (NECP 2021–2030).
While the Law also introduces rules for biomethane, low-carbon hydrogen and the development of geographically confined hydrogen networks, this note focuses on the key (green) hydrogen production provisions.
A simplified licensing route to market: The Hydrogen Producer Certificate
At the core of the new licensing regime is the Hydrogen Producer Certificate (HPC) – the primary legal requirement for any interested investor planning to develop a hydrogen production unit in Greece.
Next step
The HPC process framework is immediately actionable following the enactment of the Law. No secondary legislation is required, and applications can already be submitted via the Electronic Register operated by the national regulatory authority (RAAEY).
Key features
- Validity: 25 years, renewable once for the same period.
- Application: Fully digital, including technical documentation, land rights, water use details and project site layout and description.
- Electricity origin statement: Applicants must specify whether electricity will be: (i) directly sourced from a renewable energy plant (in which case the applicant must identify the plant and its precise location); or (ii) supplied via the electricity grid.
- Publicity and objections: Applications are published within five business days; third parties with legitimate interest can file objections within 15 days; applicants then have 10 days to respond.
- Modification: Required for changes in production capacity (+50%) or electricity sourcing method.
From licensing to operation: Milestones to reach ready-to-build status
Once the HPC is issued, developers must follow several steps to bring their project to construction and commercial readiness:
Developers must apply for environmental approval within six months of getting the HPC unless the project qualifies for an environmental licensing simplified process.
Key precedent: In 2024, Hellenic Hydrogen was granted the first such Environmental Terms Approval (ETA) for a 100 MW unit at the former Amyntaio–Filotas lignite-fired power plant site – setting a benchmark for the environmental licensing of large-scale hydrogen projects.
- Grid connection (for injecting units)
Developers intending to inject hydrogen into the natural gas or hydrogen networks must apply for grid connection terms and sign a Grid Connection Agreement with the competent operator. This step must be completed within 36 months of HPC issuance.
For standalone projects not connected to a grid, developers must sign a monitoring agreement (Measurement and Control Agreement) with the competent operator to track hydrogen production and delivery.
- Installation and operation approvals
Once environmental licensing and grid connection steps are in place, developers must obtain installation approval to begin the construction of the unit. After completing installation and any required connection works, the unit enters its trial operation period, which may last up to six months, extendable for another four months if justified. Upon completion of the trial operation, the developer must submit the required documents to receive the operation approval. Both approvals (installation and operation) are governed by the general licensing framework for manufacturing activities, including industrial facilities, under Law 3982/2011.
Most of these licensing steps can proceed in parallel. The Law foresees a typical timeframe of 24 months to reach ready-to-build status, with the option to extend to 36 months if justified.
Certifying hydrogen as renewable: Key conditions
To be certified as renewable hydrogen, the electricity used must meet the conditions of Delegated Regulation (EU) 2023/1184. The Law reflects this EU framework and sets out two alternative paths depending on the electricity source.
- If electricity is sourced directly from a renewable power plant, no further justification is needed; the hydrogen can be classified as renewable, provided the power plant and its location are clearly identified in the application.
- If electricity is sourced from the electricity grid, specific conditions must be met regarding the location of the power plant, the share of renewable energy in the area’s power mix, the hydrogen unit’s operating hours and the carbon intensity of the electricity used.
If these baseline conditions are not met, hydrogen can still qualify as renewable if the following stricter criteria are fulfilled:
- Additionality: Hydrogen is produced from non-subsidised renewable energy power plants.
- Temporal correlation: Hydrogen must be produced at the same time that the renewable electricity is generated.
- Geographic correlation: The hydrogen production unit and the renewable energy power plant must be located in the same bidding zone (currently aligned with the borders of the Greek interconnected system).
Meeting these criteria allows the hydrogen to qualify as renewable and be certified accordingly by DAPEEP, the Greek Guarantees of Origin (GoO) issuing body. This certification is key for accessing state aid, participating in renewable hydrogen PPA s and proving compliance with decarbonisation targets.
Public support for hydrogen projects: Investment and operational aid
The Law provides a clear legal basis for granting financial support to renewable hydrogen projects that hold a valid HPC. Such support may include investment aid and/or operating aid, and will be subject to the following conditions:
- State aid approval: All support schemes must be approved by the European Commission under the EU state aid rules (Articles 107 and 108 TFEU) and the recently adopted Clean Industrial Deal State Aid Framework (CISAF), and their implementation must follow the terms of the relevant decision.
- Funding sources: Aid may be channelled through Greece’s Public Investment Programme, subject to compliance with national budgetary limits and Law 5140/2024.
- Pre-approved aid: Renewable hydrogen projects that have already secured European Commission approval for individual aid schemes prior to the entry into force of the Law remain eligible to receive that support.
One notable example is the 50 MW green hydrogen project in Corinth developed by Motor Oil Hellas, which was awarded €111.77 million in direct investment aid under the Recovery and Resilience Facility (RRF), following European Commission approval.1 The project has also attracted an additional €26 million in funding under Horizon Europe for associated R&D initiatives (Ephyra and Trieres), reflecting the growing alignment of Greek hydrogen investments with EU-level support mechanisms.
Conclusion: From legal framework to market activation
The new hydrogen law provides Greece’s first dedicated framework for the licensing, certification and support of renewable hydrogen production. It aligns domestic legislation with key EU instruments, notably Directive (EU) 2024/1788 and Delegated Regulation (EU) 2023/1184, and sets out a clear route to market through the HPC and streamlined permitting steps.
Its adoption is timely, following significant investor interest and the early development of strategic hydrogen projects. Notably, even prior to the Law, several initiatives progressed under Greece’s general licensing regime for industrial facilities, including Motor Oil’s 50 MW project in Corinth and Hellenic Hydrogen’s 100 MW plant in Amyntaio, both of which have initiated permitting and funding steps. This early activity underscores market momentum and suggests a potential first-mover advantage for developers able to navigate the emerging regime. Several additional projects are expected to advance through licensing in 2025–2026.
At this stage, however, the framework remains incomplete. Key implementation steps such as technical standards, permitting procedures and grid access rules have yet to be defined. These will be addressed through secondary legislation, and additional legal instruments will be needed to ensure full alignment with Directive (EU) 2024/1788 and to introduce complementary measures.
At the same time, renewable hydrogen presents a scalable solution for absorbing surplus renewable electricity – currently curtailed due to limited demand and storage – and positions Greece as a potential regional export hub. Unlocking this potential will require coordinated action across policy, funding, infrastructure and system operations.
While Greece’s hydrogen strategy is clearly moving in the right direction, translating this policy vision into a bankable market will require not only regulatory clarity but also financial incentives, infrastructure planning and coordinated stakeholder engagement across sectors. For investors, close monitoring of upcoming legislation, subsidy schemes and market developments will be essential to identifying viable entry points in what promises to be a high-growth sector.
- See European Commission’s approval decision for the granting of aid to Motor Oil Hellas for the project under the RRF.
Client Alert 2025-189
