Bio-bean has been using coffee to deliver energy for a short while now, giving households the ability to burn coffee instead of wood for their fires.
Bio-Bean's plant can recycle 50,000 tonnes of waste coffee a year.
It's a so-called B20 biofuel (20 percent biodiesel, 80 percent petroleum diesel) that Bio-Bean makes by collecting the used grounds, extracting the oil, and blending that with regular diesel.
Both also revealed that the biofuel being produced, which includes coffee oil, can be used in the buses without the need for modification. A good idea can come from anywhere, but with the scale and commitment of Shell, we can help enable true progress. The company is already working with the likes of Costa and Network Rail to create a supply of waste coffee grounds. The resulting waste from our caffeine addiction is then usually sent to a landfill where it has the potential to emit a whopping 126million kg of CO2.More news: Huge fire rips through block of flats in NY
"We're pleased to be able to support Bio-Bean to trial this innovative new energy solution which can help to power buses, keeping Londoners moving around the city - powered in part by their waste coffee grounds", she added.
It collects waste grounds from high street chains and factories, which are dried and processed to extract coffee oil.
The coffee waste is taken from factories, restaurants and cafes. According to the BBC waste byproducts from cooking oil and tallow from meat processing is already fueling some of the city's bus fleet.
Bio-bean founder Arthur Kay, a Stanford University graduate, told the site that the company hopes to expand next to France, which consumes 38 billion cups of coffee a year, but recognizes there will always be more diesel than coffee in the world - at least, for the time being. No other reproduction or distribution is permitted without prior written consent.