Electric cars seem downright inefficient compared to the Bio-Bug, a VW Beetle rigged to run on biogas, or methane gas generated from human waste during the sewage treatment process. The Beetle, designed by British sustainable energy company GENeco, performs like a regular car--except it can take compressed methane gas in the tank along with regular gasoline.
At first glance, the Beetle appears to be a publicity stunt for GENeco, which owns a number of waste treatment sites in the U.K. But consider this: A single sewage treatment plant in Bristol, England generates 18 million cubic meters of biogas each year. The Bio-Bug squeezes out 5.3 miles per cubic meter of biogas. So just one sewage treatment plant could keep cars running for 5,400,000 miles each year, according to the British Daily Mail .
So why don't all of our vehicles run on biogas? Compressed natural gas is used extensively in some U.S. states--California, for example, has 90 public fueling stations in the Southern half of the state. But while federal tax credits are available for new CNG vehicles, the conversion process requires a certificate from the EPA: one that costs up to $50,000.
But the biggest reason that CNG vehicles often fly under the radar is a lack of public awareness. Stunts like the Bio-Bug could at least start to change that.