Brits may prefer tea, but their busses will be getting a buzz from coffee. U.K. startup bio-bean, Shell, and Argent Energy have teamed up to fill London’s double-deckers with an innovative new java-based fuel. According to CNN, bio-bean has already brewed up 6,000 liters (1,585 gallons) of the high-octane joe, an amount able to power one city bus for an entire year. So, how is the coffee oil manufactured?