Natural gas has not proven popular for vehicles bought by individual consumers, but some fleet operators continue to find it an attractive alternative to gasoline and diesel.
That's because the lack of public fueling infrastructure proves a major drawback for natural-gas passenger cars, but fleets can circumvent that by operating their own centralized fueling stations.
That's the case with UPS, which invested $100 million in natural-gas fueling stations and vehicles last year, and now plans to expand that program.
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The company will spend an additional $90 million on compressed natural gas vehicles and stations, as well as liquefied natural gas vehicles.
CNG remains in its gaseous form, while LNG is cooled until it liquefies.
The denser LNG can be transported in tanker trucks, while CNG is generally transported by pipeline.
UPS natural gas fueling station
UPS plans to add 390 CNG tractors and terminal trucks, as well as 50 LNG vehicles, as part of this latest initiative.
It will also build six new CNG fueling stations, to be located in: Ontario, California, Orlando, Florida, Salina, Kansas, Louisville, Kentucky, Greensboro, North Carolina, and Vancouver, British Columbia, Canada.
UPS currently operates 31 CNG fueling stations, spread across 15 states.
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Its CNG vehicles operate in 38 states, as well as Germany, The Netherlands, and Thailand.
The 50 new LNG vehicles will be deployed in Chicago, Indianapolis, Nashville, and Earth City, Missouri—all locations where UPS has existing LNG fueling stations.
Some UPS fueling stations dispense renewable natural gas, also known as biomethane.
UPS liquefied natural gas truck
Unlike conventional natural gas, which is generally extracted from the ground, so-called "RNG," is derived from sources that include decomposing landfill waste, wastewater treatment plants, and agriculture.
It is distributed through the natural-gas pipeline system, and can be converted into either compressed or liquefied form.
The UPS fleet of more than 4,400 natural-gas vehicles consumed more than 61 million gallons of natural gas last year, including 4.6 million gallons of RNG.
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That reduced carbon-dioxide emissions by 110,000 tons, according to the company.
The sole factory-built passenger car to run on natural gas, the Honda Civic Natural Gas, was discontinued after the 2015 model year. Honda spent more than 15 years offering natural-gas Civics across three generations of the car, but found little retail success.
Today, of roughly 1,000 natural-gas fueling stations in the U.S., less than half are open to public access. The rest are privately owned and operated for fleet use, like that of UPS.