The Guardian has a look at a French experiment generating run-of-river hydro power in the Seine - Paris looks for power from turbines beneath the Seine.
The river Seine, the historical "sacred river" running through Paris, inspired Monet, Matisse and even the British painter Turner, who sat on its banks to capture the scenery.
Now the landscape is to undergo a subtle change, with a plan to install eight turbines underneath the city's celebrated bridges to raise energy from river currents.
Paris city hall is to launch an appeal this week for power companies to come up with suitable projects to install the turbines, or hydroliennes.
"After a study by our urban ecology service and the French waterways, four potential sites have already been identified," Denis Baupin, the deputy mayor, told Le Parisien newspaper. One is to the west of the city, at the Pont du Garigliano, while the others are in central Paris, at the Pont de la Tournelle, Pont Marie and Pont au Change. Two energy-harnessing machines will be placed at each spot.
"At these places the current speeds up a little," said Baupin. "The idea is to locate all the natural power sources that we have in Paris and that we might be able to exploit."
French energy company EDF has already declared the idea "interesting".
The companies interested in the project have until the autumn to submit proposals. The winner will be chosen next January and the first turbines or propellers installed by next spring.
While the bulk of the machinery to harness the currents of the Seine will be hidden under water, part of the structure of many modern hydro-mill prototypes sits above the water.
Paris authorities — already experimenting with the heating of buildings with water from underground springs, and installing mini-windmills on buildings — say the project is aimed more at raising public awareness of renewable energy than powering the city.