In the Rance River estuary, EDF installed a tidal-powered power station. It has been operating since 1966 and produces electricity to cover the needs of 225,000 inhabitants, equivalent to a city like Rennes (9% of Brittany's needs). The plant itself is 390 m long and 33 m wide. It is made up of 24 "bulb" type turbines with generators of 10 MW each, through which a total flow of 6600 m³ per second passes. It has a 22 km² reservoir that houses 184,000,000 m³ of water regulated by six gates 10 m high by 15 m wide.[2]​.

The tidal power plant is a reversible hydroelectric plant, which takes advantage of both high and low tide since its turbines work in both directions, in the filling and emptying phase of the reservoir. The turbines also allow water to be pumped: at low tide, the plant works "in reverse" and pumps seawater to further raise the water level of the reservoir. Pumping allows production to be increased because it increases the height of the water fall and decreases the period of time between high tide and low tide.[2]​.

The 750 m long dam closes the river estuary and includes a lock that allows the passage of around 20,000 boats a year. A road with an average traffic of 30,000 vehicles a day (up to 60,000 in summer) takes advantage of its route to link the towns of Saint-Malo and Dinard.[2]​.

The cost per kWh was similar or cheaper than that of a conventional power plant, without the cost of greenhouse gas emissions into the atmosphere or consumption of fossil fuels or the risks of nuclear power plants (13 meters of tidal difference).

The environmental impact was quite serious, such as silting of the river, changes in salinity in the estuary in its vicinity and change of the ecosystem before and after the installations.

Other exactly the same projects, such as that of a much larger plant planned in France in the area of ​​Mount Saint-Michel, or that of the Bay of Fundy, in Canada, where there is up to 15 meters of tidal difference, or that of the Severn River estuary "River Severn (United Kingdom)"), in the United Kingdom, between Wales and England, have not been carried out due to the risk of a strong environmental impact.

The operation of a tidal power plant is simple. If it is reversible, when the tide rises the water is turbined into the reservoir and vice versa when the tide falls.

Currently, electricity is transported by cables on artificial islands, where there are more turbines.

In the Rance River estuary, EDF installed a tidal-powered power station. It has been operating since 1966 and produces electricity to cover the needs of 225,000 inhabitants, equivalent to a city like Rennes (9% of Brittany's needs). The plant itself is 390 m long and 33 m wide. It is made up of 24 "bulb" type turbines with generators of 10 MW each, through which a total flow of 6600 m³ per second passes. It has a 22 km² reservoir that houses 184,000,000 m³ of water regulated by six gates 10 m high by 15 m wide.[2]​.

The tidal power plant is a reversible hydroelectric plant, which takes advantage of both high and low tide since its turbines work in both directions, in the filling and emptying phase of the reservoir. The turbines also allow water to be pumped: at low tide, the plant works "in reverse" and pumps seawater to further raise the water level of the reservoir. Pumping allows production to be increased because it increases the height of the water fall and decreases the period of time between high tide and low tide.[2]​.

The 750 m long dam closes the river estuary and includes a lock that allows the passage of around 20,000 boats a year. A road with an average traffic of 30,000 vehicles a day (up to 60,000 in summer) takes advantage of its route to link the towns of Saint-Malo and Dinard.[2]​.

The cost per kWh was similar or cheaper than that of a conventional power plant, without the cost of greenhouse gas emissions into the atmosphere or consumption of fossil fuels or the risks of nuclear power plants (13 meters of tidal difference).

The environmental impact was quite serious, such as silting of the river, changes in salinity in the estuary in its vicinity and change of the ecosystem before and after the installations.

Other exactly the same projects, such as that of a much larger plant planned in France in the area of ​​Mount Saint-Michel, or that of the Bay of Fundy, in Canada, where there is up to 15 meters of tidal difference, or that of the Severn River estuary "River Severn (United Kingdom)"), in the United Kingdom, between Wales and England, have not been carried out due to the risk of a strong environmental impact.

The operation of a tidal power plant is simple. If it is reversible, when the tide rises the water is turbined into the reservoir and vice versa when the tide falls.

Currently, electricity is transported by cables on artificial islands, where there are more turbines.