The Centrale Electrique de l’Ouest Guyanais (CEOG) project under construction in French Guiana will be the world’s biggest hydrogen-based renewable energy storage facility, upon completion.

Also called the Western French Guiana power plant, the project includes a 55MW photovoltaic (PV) solar park and a 128MWh hydrogen-based energy storage system, along with a battery for short-term energy storage.

The equity stakeholders in the CEOG green hydrogen power project include Meridiam (60%), French West Indies refinery company SARA (30%), and Hydrogene de France (HDF, 10%).

While HDF conceptualised and designed the innovative project, Meridiam, an infrastructure investment firm and asset manager based in France, became the majority equity partner of the project in September 2018.

The project partners reached financial closure on the £147m ($200m) project in September 2021 and launched construction in the same month.

Scheduled for commissioning in April 2024, CEOG will be the world's first baseload renewable energy power plant using hydrogen technology.

Location and site details

The CEOG hydrogen-based energy storage project is being developed near Saint-Laurent-du-Maroni in north-western French Guiana.

French Guiana is situated in northern South America, close to the equator. It, therefore, boasts 12 hours of daylight throughout the year, which will allow the CEOG solar-cum-green hydrogen power project to operate consistently as a baseload facility all year round.

Power offtake from the CEOG hydrogen power plant

The CEOG power project is backed by a 25-year power purchase agreement (PPA) signed with the French utility EDF.

It will be connected to French Guiana’s electricity grid through EDF’s substation in Saint-Laurent-du-Maroni.

The facility will provide reliable and clean electricity to power up to 10,000 French Guiana households. It will meet half of the energy demand in Saint-Laurent-du-Maroni and the Mana commune of French Guiana.

CEOG solar and hydrogen power plant make-up

The CEOG power project will combine a 55MW PV solar farm and a 16MW high-pressure alkaline electrolyser to break water into hydrogen and oxygen using photovoltaic electricity.

The facility will house a hydrogen storage unit to store 128MWh of electricity in the form of hydrogen and use fuel cells to combine hydrogen and oxygen to generate 3MW of electricity during night. The project will also include a battery storage system.

The CEOG integrated solar and green hydrogen power plant will deliver a fixed electrical output of 10MW from 8am to 8pm and 3MW from 8pm to 8am daily without emitting any harmful gases.

The innovative power plant will produce 100% renewable, stable and cheaper electricity by preventing the combustion of approximately 12 million litres of diesel and offsetting approximately 39,000 tonnes (t) of carbon dioxide (CO2) emissions a year.

Technologies used in the CEOG green hydrogen power project

The CEOG project is based on the Renewstable® power plant technology designed and developed by HDF to provide continuous or on-demand clean electricity from intermittent renewable energy sources.

HDF is also supplying multi-megawatt hydrogen fuel cell systems for the project. It collaborated with Ballard Power, a fuel cell technology company based in Canada, to build two 1.5MW fuel cell systems in December 2019.

The heavy-duty fuel cell systems will incorporate Ballard’s proprietary proton exchange membrane (PEM)-based, liquid-cooled, fuel cell stack technology named FCgen®-LCS.

McPhy Energy, a leading hydrogen production and distribution equipment supplier based in France, is providing its Augmented McLyzer high-pressure alkaline electrolysis technology for the project.

Operating at a pressure of 30 bar, the 16MW McPhy Augmented McLyzer high-power electrolyser will produce approximately 860t of green hydrogen a year.


The CEOG power project is being financed through long-term senior debt, equity bridge loan, tax credit bridge loan, and debt service credit facility from a group of development banks and commercial banks.

The lenders include the Agence Francaise de Developpement (AFD), French public investment bank Bpifrance, the European Investment Bank (EIB), BNP Paribas, French financial services group Credit Industriel et Commercial (CIC), and Sumitomo Mitsui Banking Corporation Bank International (SMBC BI).

The project will also benefit from subsidies granted by the French Environment and Energy Management Agency (ADEME).

Contractors involved in the Western French Guiana hydrogen power project

Siemens Energy has been awarded the engineering, procurement, and construction (EPC) contract for the CEOG power project.

McPhy Energy was selected to supply the electrolyser for the CEOG renewable electrolysis and fuel cell plant in September 2021.

Linklaters, a global law firm based in London, UK, provided legal advisory services to the lenders, while the EIB was advised by Allen & Overy, another law firm based in London.

DNV, a risk management and quality assurance firm based in Norway, provided technical advisory services to the lenders for the CEOG green hydrogen power project.

Whereas, Willkie Farr & Gallagher, an international law firm headquartered in New York, US, advised the sponsors in project financing.