The past, present and future of Paris are closely tied to the city’s underground. The sewers network that today serves as the shooting ground for movies, could be used to harness hydrokinetic and geothermal energy.
Reuters reports that temperatures in the French city’s sewers can go up to 68°F (20°C). This essential condition allows for a geothermal system to be set up: a special heat-conveying fluid-filled pipe passes through the warm sewage, pulling the energy out of it. As a reassuring detail, this closed system does not allow for any stench to come out.
And again, the underground of the Elysee Palace will remain in history – this time not as the passage for any romantic purposes, but as one of the first locations to try out this experiment. A town hall and a public swimming pool are also on the list for researchers to see if they could get geothermal sewer energy and make this a viable project.
For the moment, the experiment has one big downside: the system only works if the source is closer than 600 feet to the heat extraction area. In consequence, only about 10% of Paris could stand up for the challenge. On the other side of the ocean, the US has enough geothermal potential to get by, so a sewage system like the French one wouldn’t have the impact of a saving solution. But it is one to be considered, as an option among others.