When it comes to renewable energy sources, an often overlooked fuel is right under our noses. Human waste, collected and processed in waste treatment plants just about everywhere there are humans, can be used to produce renewable natural gas that just so happens to be a great way to fuel vehicles, produce heat, and electrify anything that needs electricity. The city of Grand Junction in Colorado is going where few have dared to go before, relying on converted poo to power 40 city vehicles.
Many municipalities use anaerobic digestion to convert waste into raw biogas, but then it is typically burned off in a flare, which is considered a low-emission method of disposing of methane and other gases emitted from waste. The process of transforming waste into truck fuel adds a few steps. After anaerobic digestion breaks down organic matter, the resulting biogas can be upgraded to renewable natural gas (RNG), also known as biomethane. The fuel is then suitable for a variety of energy applications.
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By capturing and cleaning the raw biogas into a usable form of energy, Grand Junction’s Persigo Wastewater Treatment Plant is seizing an underutilized opportunity, and they think they’re the first in the nation to do it. “As far as we know, we are the only municipal wastewater facility in the nation producing biogas used as vehicle fuel,” Dan Tonello, wastewater services manager for Grand Junction, told the Guardian. Now, that poo power is being used to fuel 40 of the city’s fleet, including garbage trucks, street sweepers, dump trucks, and transit buses.
Creating truck fuel from human waste reduces the city’s greenhouse gas emissions by up to 80 percent, according to Bret Guillory, the city’s utility engineer. The project, which cost around $2.8 million over the last 10 years, is not just a win for the environment; it also stands to save the city a lot of money. “The project will pay for itself in around seven years,” Guillory said. “Not a bad return on the investment.”
Via The Guardian
Images via City of Grand Junction