Google recently detailed how it uses recycled wastewater to cool the servers in its Georgia data center, but a company in Philadelphia is now going to be using sewage water to heat a building. NovaThermal Energy has installed a wastewater geothermal heating system in the basement of the Southeast Water Pollution Control Facility in Philadelphia in what the company is calling the technology's first deployment in the United States. The Philadelphia Water Company, of which the building is a part, manages the city's wastewater, stormwater — and somewhat ironically, its drinking water. The 1 million BTU per hour geothermal unit uses a water source heat pump, outfitted with a filtration device, to transfer heat directly from an adjacent sewage channel and turn it into electricity, providing heat for the building at an estimated cost savings of 50 percent.

The technology itself has already proven successful in China, according to the company, though NovaThermal has the exclusive rights to exploit it in the US. The Philadelphia project is clearly part of a long-term strategy for the company, with Temple University providing systems analysis in preparation for a white paper it will be publishing on the efficiency of the system. For its part, NovaThermal sees the solution as an energy-efficient method of heating that could prove to be a boon for commercial and industrial buildings.