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​Poop Power Is a Surprisingly Versatile Fuel Source

The UK just debuted buses that run on sewage. But that’s just the latest innovation in the millennia-old story of poop-based fuel.
November 21, 2014, 11:00am
​Poop. Image: Shutterstock

On Thursday, the UK debuted its first poop-powered buses, which will transport about 10,000 monthly comm​uters between Bath and Bristol Airport. These "Bio-Buses" are the fruit of a partnership between the Bath Bus Company and Bristol's sewage treatment system, which is run by a company called GENeco. They can travel about 186 miles on the yearly waste of five people, offering a more sustainable alternative to natural gas-powered vehicles.

GENeco's promotional video about the Bio-Bus. Credit: YouTube/GENeco

"Gas-powered vehicles have an important role to play in improving air quality in UK cities," GENeco general manager Mohammed Saddi told​ the Guardian. "But the Bio-Bus goes further than that and is actually powered by people living in the local area, including quite possibly those on the bus itself."

What a simultaneously exciting and unsettling thought. But regardless of whether passengers wonder if last week's lunch is propelling them across England, the buses are a clear sign of the UK's commitment to repurposing waste as fuel. GENeco is also using Bristol's waste facilities to help power thousa​nds of homes, and Sainsbury's supermarket chain is already using food waste to generate energy for its stores, as our own Vicki Turk reported earlier this ​year.

The British may be the current frontrunners in this arena, but the idea of using waste, specifically the scatological variety, goes back millennia. Archeological evidence of dry animal dung as a fuel source for fires is scattered all around​ the Mediterranean, and over on the other side of the Atlantic, the Inca used llama dung for both heat and to fashion their c​eramics.

Even the Bible has a wonderfully messed up passage about using poop as fuel. Ezekiel 4:12 rea​ds, "And thou shalt eat it as barley cakes, and thou shalt bake it with dung that cometh out of man, in their sight." Best leave that nugget to the theologians to parse.

True to its rich history, poop-based energy has now evolved into a multifaceted and diverse set of industries. In 2004, a waste management facility in Renton, Washington received a $22,000,000 gr​ant to build a power plant that could turn sewage into electricity. The same year, a rancher figured out how to power his dairy far​m with cow patties and an engineering professor turned pig crap into​ crude oil.

These examples illustrate that by the 21st century, sophisticated poop-based power had been accepted as a real possibility by the public, business, and academic spheres. It was further launched to new heights in 2011, when the Gates Foundation launched the ReInvent the ​Toilet Challenge in 2011.

As our Kaleigh Rogers wrote on Wednesday—aka World Toilet Day—the challenge addressed the need for more environmentally sewage disposal, especially in the developing world. Caltech ended up wi​nning the campaign with a solar-powered toilet that can convert waste into hydrogen fuel cells and fertilizer. The campaign proved that toilets can function like miniature power plants operating in every home, reducing waste output and energy intake simultaneously.

And it's not just human poop, either. Manure-fueled biogas facilities are becoming more common, and one mas​sive new project in Missouri points to the future. The $80 million facility involves covering some 88 hog waste lagoons—poop lagoons, yeah—and capturing waste gas for processing in biogas digesters.

Recently, even more exotic extraction techniques are being applied to poop, right down to the atomic level. A study published yesterday in the Journal of the Royal Society Interface revealed how bacteria release electrons when they interact with iron. This reaction produces an electrical charge that can ​be captured and used to increase the efficiency of bio-batteries, which could in turn be used to power Smartphones, among o​ther electronics. That's right: the device you read while dropping deuces could actually run on said deuces.

Clearly, the future of poop power is bright, and the UK's new Bio-Buses are just the latest step in a storied history. Given that every person creates about 700 ​pounds​ of the stuff a year, it's past time we got serious about polishing those turds, and powering our lives with them.