Compressed Natural Gas (CNG)
Natural gas stored under high pressure as a vehicle fuel. Established in refuse and transit fleets, and it commits the agency to its own fueling infrastructure.
Compressed natural gas is stored in high-pressure cylinders on the vehicle. It has a long track record in public fleets, particularly refuse and transit, where vehicles return to one yard every night.
The decision is about the station rather than the vehicles. CNG generally means building and maintaining a compression and dispensing facility, which is a significant capital project with its own maintenance and code obligations. That is why it suits large single-depot fleets and rarely suits small mixed ones.
Cylinders also carry inspection and service-life requirements of their own, which is a maintenance obligation a fleet does not have with liquid fuel.
