A small Minnesota city is exploring the possibility of extracting energy from a resource that almost never runs dry: sewage.
In Brainerd, Minn., a local company, Hidden Fuels, has been studying the viability of using energy from sewage. It found that energy from the city's wastewater could heat hundreds of homes and municipal buildings, like the public high school.
It's working on a system that would work much like a geothermal system, using the warm water from hot showers and sinks, except that the water used for this project would be far from clean, NPR reports:
A similar system was used during the 2010 Winter Olympics in Vancouver, Canada, but that setup didn't tap an existing sewer.
"We're not dealing with clean fluids," [Peter] Nelson [of Hidden Fuels] says. "We're dealing with contaminated fluids. And so that's really the challenge ... to be able to operate efficiently in that contaminated environment."
Nonetheless, a system has been put to use to heat the city's public utilities building from wastewater for 14 years, according to the local newspaper, Brainerd Dispatch. If the city can make this energy system economically viable on a larger scale, as many as 450 homes will be able to tap into its heating power.
It's a smart energy solution. But it's not surprising coming from a city with "brain" and "nerd" in its name.