Thassalia, the first marine geothermal plant

Thassalia will be the first geothermal power plant in France to operate using salt water, and it will transform the Mediterranean into a sustainable source of energy for an nearly 500,000 m2 of buildings.

The marine geothermal power plant will be situated in the Port of Marseille. A pumping station will draw water from a depth of up to 5 meters, where the water is at a constant temperature. Heat pumps will recover energy from the sea for transfer to the district heating and cooling network. This 3 km-long urban network will cool buildings in summer and warm them in winter. Eventually, the network will service 500,000 m2 of buildings, including the Euromed Center, Les Docks and future Arenc Residential Park.

How does marine geothermal energy production work?

Marine geothermal energy works by making use of the temperature differences between warm surface water and cold water at greater depths, which is pumped through kilometer-long pipelines. Water is pumped into the sea and along the coast, where exchangers and heat pumps regulate production based on heating and cooling needs. The water is then channeled to heat or cool buildings.