Technical and Economic Analysis of the 50 MW Project in Corinth

In February 2026, Metacon announced an expansion of its contract with the Greek refinery Motor Oil Hellas (MOH) to include an oxygen purification system. This event marks the end of an era where oxygen was treated as a waste product of electrolysis, opening a new chapter in the optimization of operating expenses (OPEX) for hydrogen plants. We analyze the financial mechanisms, technical challenges, and regulatory context of one of Europe’s most significant hydrogen investments.

1. Investment Context: Corinth Refinery and the TRIERES Project

The Corinth refinery, owned by Motor Oil Hellas, is Greece’s largest industrial complex, with a refining capacity of 255,000 barrels of oil per day. Under its Strategy 2030, MOH aims to transform into a low-carbon energy hub. A central element of this transition is the construction of a 50 MW electrolysis plant.

This investment is the focal point of the TRIERES project (Greece’s first „Hydrogen Valley”), funded by the Clean Hydrogen Partnership and the Horizon Europe program. The project aims to produce approximately 2,410 tons of green hydrogen annually and create a complete value chain—from maritime transport to heavy industry.

2. Technological Architecture: PERIC and Metacon

The plant utilizes pressurized alkaline technology provided by the Swedish company Metacon, under license from the Chinese leader PERIC Hydrogen Technologies. The choice of alkaline technology for a 50 MW scale stems from its maturity and lower unit costs compared to PEM or SOEC technologies.

Stack Technical Specifications:

Modularity: The project is based on 5 MW stacks.
Efficiency: PERIC systems feature energy consumption of approximately $4.3–4.5\text{ kWh}/Nm^3\text{ }H_2$ at the stack level.
Local Integration: Metacon performs adaptation and production at its facilities in Patras, Greece. This allows Chinese technology to be tailored to rigorous EU safety standards (PED Directive, CE certification).

3. Breakthrough in Oxygen Management: The $2,000\text{ }Nm^3/h$ Contract

The latest contract amendment, valued at €976,290, covers the delivery of an oxygen purification system with a capacity of $2,000\text{ }Nm^3/h$. While water electrolysis generates 8 kg of oxygen for every 1 kg of hydrogen, this gas has historically been vented into the atmosphere due to the costs of drying and purification.

Why does a refinery need pure oxygen?

In refining, oxygen is a critical raw material, typically supplied by energy-intensive Air Separation Units (ASU) or external liquid oxygen (LOX) deliveries.

Sulfur Recovery Units (Claus): Enriching process air with oxygen increases throughput without physical furnace expansion. Oxygen accelerates the oxidation of hydrogen sulfide ($H_2S$), which is vital when processing heavier, high-sulfur crude oils.
Fluid Catalytic Cracking (FCC): Using pure oxygen in the catalyst regenerator allows for more intense coke combustion, directly translating to higher gasoline and LPG yields.
Wastewater Treatment: The refinery generates vast amounts of process water. Oxygen is essential in biological reactors to reduce COD (Chemical Oxygen Demand).

4. Financial Mechanisms and Public Support

The Corinth project serves as a model for financial engineering. In February 2025, the European Commission approved €111.7 million in state aid for Motor Oil Hellas, funded by the Greek Recovery and Resilience Facility (RRF).

Additionally, the project benefits from grants under the EPHYRA initiative (Horizon Europe), covering risks associated with innovative solutions, such as integration with waste heat recovery systems from Orcan Energy. Market analysis suggests the cost of oxygen from an ASU ranges between €0.08–0.15/kg. By utilizing Metacon’s system, MOH can significantly lower the LCOH (Levelized Cost of Hydrogen) by offsetting the market value of recovered oxygen against the electrolyzer’s OPEX.

5. Legal Framework: Greece’s New Hydrogen Law

In July 2025, Greece passed Law 5215/2025, establishing the country’s first comprehensive licensing and certification system for renewable hydrogen. It introduced the concept of „Geographically Confined Hydrogen Networks” (GCHN), allowing the Corinth refinery to build dedicated transport infrastructure without needing the status of a National Transmission System Operator (TSO). This regulatory clarity accelerated the decision to invest in gas purification systems.

6. Technical Challenges and Project Risks

Despite the project’s advancement, Metacon and MOH face several barriers:

Safety ($H_2$ in $O_2$): The primary challenge in alkaline electrolysis is hydrogen diffusion into the oxygen stream, especially during partial load operation (below 20–30% power). Metacon’s purification system must precisely remove trace $H_2$ to avoid explosive mixtures.
Pressure Logistics: Oxygen exits the electrolyzer at a lower pressure than required by the refinery’s industrial network. Compression requires additional energy (approx. $0.2–0.4\text{ kWh}/kg\text{ }O_2$), which must be factored into the energy balance.
Geopolitical Risk: Reliance on PERIC technology (China) amidst tightening EU Net Zero Industry Act regulations may force Metacon to accelerate the full „Europeanization” of its supply chain.

7. Comparative Analysis: Metacon’s European Portfolio

Parameter	Alkaline (Greece/Sweden)	PEM (Slovakia)	Biogas Reforming (Germany)
Maturity	Very High	High	Medium / Innovative
Main Advantage	Low CAPEX for large scale	Rapid response to RES	Use of waste (biomass)
By-products	Oxygen, Heat	Oxygen, Heat	$CO_2$ (Biogenic capture possible)
Application	Heavy Industry, Refineries	Urban Transport, Logistics	Local Energy Independence

Global Project Highlights:

Germany (Kempten): Using the HHG-50 system to reform biogas from wastewater treatment, producing 36 tons of $H_2$ per year with 99.999% purity.
Slovakia (JESS Project): A 1 MW PEM electrolyzer in Bratislava producing 400 kg of $H_2$ daily for 350-bar bus refueling.
Sweden (Botnia Hydrogen): Operating in Arctic conditions, integrating alkaline electrolyzers with 350/700-bar refueling stations.

8. Conclusions for the Polish Market

The Corinth project mirrors the challenges faced by Polish giants like Orlen (Płock) or Grupa Azoty. The lesson from Greece is clear:

Oxygen Monetization: For installations over 20 MW, oxygen purification systems pay for themselves within 3–5 years by reducing industrial gas purchases.
RRF Synergy: Utilizing RRF/KPO funds for „multi-product” projects increases the likelihood of a positive EC decision.
Regulatory Necessity: The Polish hydrogen industry requires simplifications for local hydrogen and oxygen networks, analogous to the Greek Law 5215/2025.

Data Sources:

Metacon AB Annual & Year-end reports (2024–2026).
H2 View: „Metacon to add oxygen purification to 50MW refinery electrolyser in Greece” (Feb 16, 2026).
European Commission Decision SA.104899.
Greek Government Gazette, Law 5215/2025.