When water from the shower, dishwasher, or washing-machine is drained into the sewer-pipes, it's not just a waste of water, but a waste of the energy used to heat that water. In fact, the water in city pipes averages a temperature of 68°F--energy-produced heat that is simply wasted. This unused energy pestered folks in one French town so much that they decided to put it to good use... and now it heats their swimming pools. A Green Town and a Green Councilwoman
Levallois-Perret, a suburb of Paris, is on the forefront of the local greening efforts. Their pool-heating system has done wonders in cutting energy costs and reducing their carbon emissions. Plus, now they can swim year-round--that's nice too.
How does a town get the notion to undertake such a great green idea? Well, it all starts with one person--in this case, it was Sophie Deschiens. She's the town's Environment Councilwoman, and she is efficient:
When I heard the amount of heat lost in the sewers, I decided I had to do something.
Her dedication to make her town less wasteful led Deschiens across the world in search of a solution, which she found in the form of a technology that allows heat to be recovered from the sewers.
Capturing the Sewage's Heat is Easy
Such a system actually works quite simply. A series of stainless steel plates is attached to the bottom of the sewer pipes, equipped with a special liquid that captures the heat, according to a report in O Estado. That captured heat can then transferred to be used to warm something else.
Deschiens first thought was of a new aquatic center being built in the city, and that the system could be used to heat its pools, spas, and jacuzzis. In fact, the heat captured from the sewer-pipes would be enough to heat the center's water to a piping 85°F all year.
With this in mind, she teamed up with a local business and able to get the project approved. Although it was a bit pricey at $650 thousand, Deschien expects the project will pay itself off in a decade. It's also expected to reduce the city's energy costs a whopping 24% and bring a drop of 66% in greenhouse gas emissions.
Where is Your Sewage Heat Going?
Just a few days ago, the system became operational--and the town's public swimming pool is now heated by the town's sewage. Deschiens, perhaps while taking a dip in the water she helped warm, is urging others to follow the example set by her little town:
If other cities want to copy the system, we are happy.
Hey, that's a good idea.