Researchers from Newcastle University in the U.K. have done the math, and on the surface it looks pretty grim. Every year, the U.S. flushes about 12.5 trillion gallons of energy right down the drain. They’re actually talking about potential energy, in the form of biofuels that could be recovered from wastewater. That alone could form a big part of the renewable energy picture, but wait there’s more – much, much more.
Renewable Biogas from Sewage
Regular readers of Cleantechnica are probably used to us raving about the energy potential in wastewater (yeah, sewage). Sewage-to-methane biogas equipment is becoming commonplace at treatment plants, where it is usually used to run equipment at the site. The City of San Antonio recently bumped it up a notch by selling its sewage biogas into a commercial pipeline, and we should also note that agricultural biogas is becoming a big deal, too. The U.K. researchers estimate that a gallon of wastewater contains enough energy potential to run a 100-watt light bulb for five minutes, which doesn’t sound like all that much until you multiply that by 12.5 trillion.
More Good Stuff from Sewage
In addition to biogas, sewage can yield a plethora of renewable benefits. Depending on the presence of contaminants, it can be dewatered and used as a natural soil amendment. Researchers are also looking into refining biofuel from the “trap grease” in sewage, and even making renewable bioplastics from sewage. To ice the cake, the typical treatment plant is a sprawling facility often located in a relatively remote area, providing the potential for wind turbines and solar power installations – and let’s not forget the potential for kinetic hydropower, too.
Who’s Afraid of $4 Per Gallon Gas?
Sewage-to-biogas isn’t the answer to all of our nation’s energy woes, but exploiting the energy potential of wastewater is going to play a big role in a diverse, renewable energy picture – and it’s locally sourced, too. We’re dealing with yet another price spike at the gas pump right now, but the time is fast approaching when the U.S. economy will no longer march in lockstep with global market trends for a single type of energy.
Image: Green bucket by Dwstucke on flickr.com.
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