A British startup announced it would use coffee to power some of London’s buses effective Monday, Agence France-Presse reported Friday.

Bio-bean, the startup behind the endeavor, extracted about six thousand liters of oil from ground coffee waste to fuel the city’s public transportation gasoline tanks. The startup has been extracting oil from waste coffee grounds predominantly from London-based coffee shops for four years. It has been financially and technically backed by the oil and gas company Royal Dutch Shell.

According to Bio-bean, it has produced enough coffee oil to power one bus for an entire year. The company made the fuel by extracting the oil from waste coffee grounds and combining it with diesel. The final product reportedly consisted of 80 percent diesel and 20 percent biofuel.

Arthur Kay, Bio-bean founder, won The Pitch 2013, a small business competition in which contestants compete for startup funding. He spoke to AFP about the method and practice behind the creation of the biofuel, explaining how his startup creates a renewable substance.

“Instead of sending a ton of waste coffee grounds to landfill where it degrades and releases methane and CO2, we collect it, recycle it and turn it into a renewable fuel which is then used to replace further conventional fuel,” the 27-year-old Stanford graduate said. “It’s double saving.”

Once the waste coffee grounds are extracted from the coffee shops, they are sent to Bio-bean’s factory in Cambridgeshire. The extracted coffee oil is then sent to Argent Energy, Britain’s largest biofuel producer. Bio-bean said replacing traditional fuel with the coffee fuel can reduce bus ride carbon emissions by 10 to 15 percent, with no modifications or extra spending required. The coffee fuel could also potentially be used by other vehicles, such as cars and trucks.

“We’re not saying that it’s going to replace fossil fuels overnight. The amount of diesel produced globally is always going to be more than the amount of coffee,” Kay said. “We want to see an entrepreneur going and doing something cool with waste from beer, or from tea.”