Methane is the principle component of natural gas, making the Bio Bug akin to the Civic GX we featured in Translogic Episode 6.2. But the BioBug's fuel comes from "biogas," which is collected from the biological breakdown of organic matter that accompanies sewage treatment. Before being used in automotive applications, biogas needs to be "upgraded" by having carbon dioxide separated.
Once that happens, performance is the same as a regular car, says project engineer Mohammed Saddiq. "It's absolutely no different, there's no deterioration in performance, it drives like it would running on petrol. There's no odor coming out of the exhaust."
Biogas-powered cars are nothing new. Volvo introduced a prototype about five years ago and continues to explore its uses for commercial vehicles. The trick here is that while biogas technology often involves collecting naturally occurring methane gas from landfills and oil wells, the biogas used in the Bio Bug comes from anaerobic bugs that digest sewage in giant processing tanks -- much like the bugs in your stomach digest your food, creating that other type of gas.
"Anaerobic digestion has been around for hundreds of years," says Saddiq. "We just put the bits of the jigsaw together to demonstrate we can get a car powered by bio gas."
Sweden and the U.K. traditionally lead Europe in biogas technology, but similar projects exist in the U.S.
The Bio Bug project came about when British water-treatment company Wessex Water looked into whether it could harness a gas byproduct from its massive sewage plants to minimize its own carbon footprint. In doing so, it discovered that not only could such a byproduct power its entire vehicle fleet, but it could also be used to power automotive infrastructure on a much larger scale.
Geneco, the subsidiary that launched the Bio Bug project, treats the waste of about 2.3 million customers. Last year it set a goal to become a carbon neutral company by 2020 in part by developing energy-saving technologies. Saddiq says that by harnessing its methane byproduct and using the additional energy to power its treatment plant, the water company has cut its energy costs by 42 percent. It's even started exporting spare electricity to the U.K. grid.
Saddiq says that the methane gas harvested from one sewage plant could be enough to power some 95,000,000 miles and a year's sewage from just 70 homes can power the Bio Bug for about 10,000 regular driving miles. The car can be driven between 200 and 300 miles before having to top up the gas tanks -- which, flattened out for different driving conditions, works out to about 5.3 miles per 35 cubic feet of gas -- and the modified Beetle is capable of reaching its top speed of 115 mph.
Carbon dioxide emissions are similar to a regular powered car and are considered carbon neutral, as the methane gas, as a byproduct of sewage treatment, would commonly be released into the atmosphere anyway.
Distribution of the gas tanks, Saddiq says, would not be a significant problem and if the car runs out of methane, it reverts back to its regular gasoline supply. "Once the methane is stored in cylinders there is no reason why the gas couldn't be stored, then transported to [gas stations]."
Having recently looked into mixing your own biodiesel for a future episode of Translogic, we thought there was one question we absolutely had to ask Saddiq: Could a consumer harness their own waste and use it to power their car?
"They could, but the economies of scale wouldn't promote that. They'd need an anaerobic digester, separate gas cleanup systems, the solids would need to be treated, and the waste water cleaned," he said with a wry chuckle.