Select language

Need informations ?


Refine your search

Type of content

Type of challenge



To supply buildings in the new

Euroméditerranée district with
hot water, central heating and cooling


  • 500,000 sqm/m2

    of buildings to be supplied
    by 2020

  • 3km

    pipe network

  • 70%

    less greenhouse gas emissions
    than conventional systems

Marseille is the first city in Europe to use thermal energy from the sea for an urban heating and cooling system, servicing nearly 500,000 sqm/m2 of buildings. The Thalassia geothermal power station built by ENGIE draws water from the Mediterranean at a depth of 7 metres and uses it to create heating and cooling energy.

As they look to the future, Marseille’s authorities want the city’s new Euroméditerranée district to be a laboratory for sustainable living. With 480 hectares overlooking the sea and flanked by the port area, it is a massive urban regeneration scheme – featuring more than 200,000 public buildings and as many shops, along with 24,000 homes. The area is also home to a maritime geothermal power station, designed to supply a heating and cooling network for many of these buildings.

A heating/cooling network that is better for the environment

The renewable energy source par excellence, seawater is used to supply a power plant that will either heat or cool water for distribution via a city network to various buildings. The system offers numerous benefits: electricity consumption is reduced by 40% and water consumption by 65% to 100%, compared to individual heating/cooling units. It also helps to combat the ‘heat islands’ formed by individual thermal installations. In addition, there is no need to chemically treat the seawater that is pumped through and out of the system.

Fewer greenhouse

gas emissions

of the energy used by the network

is renewable

An economical solution

The geothermal solution developed and deployed by ENGIE not only helps to protect the environment, but is also economically advantageous. The Group’s €35 million investment in the project, along with a further €5.5 million from institutions including France’s national agency for the environment and energy (ADEME), the EU Regional Development Fund (ERDF), the local département and Marseille’s city and regional authorities, will be recouped in about a decade.

The cost of energy produced by the plant is also competitive in the context of rising electricity prices. Thassalia produces a kilowatt hour for the same cost as a gas-powered plant, while cooling costs 10% less than that produced using electricity.

to recoup investment

Architecture that perfectly suits the surroundings

Another advantage of Thalassia and the network connected to it is the plant’s architectural and aesthetic aspects. The Euroméditerranée district has several superb buildings, such as the CMA-CGM Tower designed by the renowned architect, Zaha Hadid. Thanks to Thalassia, the buildings it supplies with heating and cooling do not require cooling towers on top, preserving the visual harmony of the area. The power plant itself was designed by the architect Roland Carta. Built in concrete, its futuristic lines fit in perfectly with other buildings in the district, including the MuCEM designed by Rudy Riciotti.

And tomorrow ?

In an era of global warming and rapidly growing demand, expertise in cooling systems is a real advantage. For this reason, ENGIE has strengthened its position in the field by acquiring 40% of Tabreed, a company that provides integrated cooling solutions for major infrastructure projects in the United Arab Emirates and other Gulf states. ENGIE is now a world leader in district cooling schemes.

The Engie Today teams for marseille

Envie d'en savoir plus ?


Envie d'en savoir plus ?