I am often asked, “How long does it take to fuel a natural gas truck?” The answer can be surprisingly short. The fueling time depends on whether the truck uses CNG (compressed natural gas) or LNG (liquid natural gas), as well as the station design.

CNG is produced at the station using a natural gas compressor. The length of time it takes to fuel a CNG truck is entirely dependent on the station compressor. The compressor is the heart of the station because the size of the compressor determines how many gallons per minute can be dispensed. The compressor is the most expensive piece of equipment for the station to purchase, operate and maintain, with significant electricity costs for each gallon dispensed. Therefore, the station designer must find a balance between the dispensing rate (compressor size) and the compressor cost. This means that each CNG station is purpose-built for that station's expected fueling requirements - fueling taxis requires a much smaller compressor than fueling transit buses, for example.

Most public access CNG stations were built to dispense a small amount of fuel for light and medium duty vehicles. For example, fueling my CNG-fueled Honda Civic GX in 10 minutes is no problem (similar to fueling with gasoline), but fueling a class-8 truck at this same station would take a very long time - too long to be acceptable. By way of comparison, my Honda Civic GX has 8 gallons of storage while a truck can have 75 gallons of CNG storage (or more). Fueling a truck at the wrong station can take as long as an hour and as little as 10 minutes at the right one. Fleets considering deploying CNG trucks at public access fuel stations should contact Clean Energy in advance for guidance on fuel stations that will meet the fleet's fueling requirements.

Dispensing LNG is similar to dispensing diesel or gasoline in that a liquid pump is used at the station. The station pump can dispense up to 40 liquid gallons per minute, which is equivalent to 24 diesel gallons per minute. The actual fueling rate will depend on the fuel pressure in the vehicle fuel tank. The typical dispensing time at a Clean Energy LNG station is less than 5 minutes. You can watch this YouTube time-lapse video of an actual fueling event. The driver was able to load 47 diesel gallon equivalents of fuel in just over 3 minutes. How's that for rapid fueling.