Green Hydrogen and Clean Fuels in a Sustainable City | ENGIE Impact

The Role of Green Hydrogen and Clean Fuels Demonstrated in a Sustainable City Environment

Case Study
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Sustainability Transformation
Renewable Energy
Green Hydrogen

As governments around the world explore ways to integrate sustainable energy solutions into their grid, one city in Northern France has taken a novel approach. In the city of Dunkirk, ENGIE Lab CRIGEN is trialing the GRHYD project, an innovative approach that uses natural gas and hydrogen networks to create renewable energy solutions.

Achieving National Sustainability Targets

Kicking off this ambitious project in 2014, the French government set the target of meeting 23% of its gross end-user energy consumption from renewable sources by 2020. They partnered with ENGIE, who has a demonstrated history of successful energy projects.

The Renewable Energy Solution

First, the city converted a surplus of energy generated by renewable sources into green hydrogen. Then, by injecting hydrogen into natural gas networks, Dunkirk has been able to generate a renewable energy source with a broad range of applications, including:

  • Space heating
  • Water heating
  • Fuel

To evaluate the technical, economic and environmental relevance of this process, two demonstrators for the power-to-gas energy solution are now up and running in the Dunkerque Urban Community:

1. Transportation

A VNG bus fueling station will be adapted to handle the hydrogen/natural gas blend, which will begin with a 6% hydrogen content that will be increased over time to 20%. A fleet of around 50 buses will be operated using this hydrogen-natural gas blend.

2. Residential

A new residential neighborhood of around 200 homes in the Capelle la Grande district will be supplied with a blend of hydrogen and natural gas using a variable hydrogen content of below 20%. Production will be based on energy from renewable sources (wind power) injected into the power distribution network. Surplus power will be used to produce green hydrogen for storage and subsequent distribution to meet demand.

Results of Clean Fuels Trial

This cutting-edge approach to renewable energy exemplifies the hydrogen plan launched by French Environment Minister Nicolas Hulot in 2018. After 5 years of study and authorization, the first Power-to-Gas demonstrator in France yielded the following outcomes.


homes including 120 houses and 80 apartments will be supplied at completion


homes and the heating system of a clinic supplied by a new gas composed of hydrogen and natural gas during the demonstration


hydrogen technologies tested: electrolysis, storage and the injection equipment

The Impact

Dunkirk’s power-to-gas solution demonstrates how a city can drive the reduction of greenhouse gas emissions while meeting the needs of a community. As is evident in GRHYD’s technical, economic, environmental, and social impacts, power-to-gas creates an opportunity to transform renewable energy solutions as we know them.

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