Waste-to-Energy is a process of converting waste to usable energy: electricity, heat, or combustible fuel. In North America, this conversion has traditionally taken place through the use of biogas (from landfills and anaerobic digesters) for electricity generation and direct combustion for heat production.
The instances of converting waste into combustible fuel have been scarce. The process has historically taken the form of biogas purification for either on-site CNG and LNG vehicle refueling or natural gas pipeline grid injection. There are tens of thousands of biomethane-fueled vehicles in the world, but only a small portion of them are in North America. As a renewable substitute for natural gas, biomethane is a viable renewable alternative to diesel and gasoline, which underpins the increasing support for this application in recent years.