A semi truck is refueled at a ampCNG plant in Waco, Texas, similar to one that will be built this summer in Dalton, Ga.

The drop in diesel fuel prices over the past year may be slowing some truckers' enthusiasm for natural gas, but the distributors of compressed natural gas (CNG) are still adding more outlets for CNG, including new refueling stations being built this summer in Dalton, Ga., and Newport, Tenn., and possibly another new unit in Chattanooga within the next year.

A business started three years ago between two compressed natural gas suppliers for trucks known as amp Trillium LLC is spending more than $2 million to open a CNG fueling station off of Interstate 75 at exit 326 in Dalton-- one of three such stations the joint venture is now building.

Compressed natural gas stations

* Georgia: 31, including 18 public stations
* Tennessee: 17, including nine public stations
* Alabama: 25, including nine public stations
* U.S. total: 1,549, including 823 public stations
Source: Alternative Fuels Data Center, U.S. Department of Energy

About CNG

Because of the gaseous nature of natural gas, when stored onboard a vehicle, it must be in either a compressed gaseous (CNG) or liquefied (LNG) state. CNG and LNG are considered alternative fuels under the Energy Policy Act of 1992. Natural gas is sold in units of diesel or gasoline gallon equivalents (DGEs or GGEs) based on the energy content of a gallon of gasoline or diesel fuel. To provide adequate driving range for a vehicle, CNG is stored in cylinders at a pressure of 3,000 to 3,600 pounds per square inch. A CNG-powered vehicle gets about the same fuel economy as a conventional gasoline vehicle on a GGE basis. A GGE equals about 5.66 pounds of CNG.

"The new location's close proximity to Larry McDonald Memorial Highway is ideal for long-haul trucks and will provide a much-needed refueling station for CNG vehicles traveling through Georgia and Tennessee on I-75," said Donna Rolf, president of ampCNG, a Chicago-based developer of CNG stations across the country.

The new Dalton site, like the other 19 sites where ampCNG now operates outlets, is located near both an Interstate highway and a natural gas pipeline.

Steve Josephs, the co-founder and director of engineering for amp Trillium, LLC, said the company also is opening a station this summer in Newport, Tenn., and is eager to add an outlet in Chattanooga to meet what he projects will be a 20 to 30 percent annual growth in CNG fueling stations across the country.

Josephs said the projected 50 percent annual increase in CNG outlets he expected a couple of years ago is likely to only be half that pace since diesel and gas prices fell by about a third in the past year.

"The customers who were on board with CNG are sticking with us, but it's been a little slower getting new customers on board," Josephs said. "But most people think the current level of diesel prices is probably a temporary thing and the question is how temporary that is going to be."

Even with the strongest market for commercial trucks in eight years, North American sales of natural-gas-powered heavy-duty trucks were up only about 20 percent last year. More than 10,000 CNG-fueled semi trucks sold last year, according to Power Systems Research.

Natural gas-powered trucks are more expensive than most of their diesel counterparts. The relatively limited number of CNG refueling stations also has made some truckers wary about making the extra investment in CNG trucks, even though the CNG fuel is cheaper and there are federal and state tax and environmental advantages for buying trucks that use the cleaner fuel.

Josephs said he expects with the addition of more CNG refueling stations and higher diesel prices over time that more truckers will turn to natural gas for fuel.

The new Dalton outlet scheduled to open by September will include Trillium CNG's proprietary fast-fill hydraulic intensifier compressor (HY-C), which can fuel three heavy-duty trucks simultaneously at 10 diesel gallon equivalents per minute.

"We'll put a typical truck in and out of our facility in about 10 minutes or so which is really consistent with diesel refueling," Josephs said.

A similar ampCNG station opened in March 2014 in Perry, Ga., to serve Frito-Lay's fleet.

The Dalton outlet to help refuel CNG trucks for an Indiana dairy cooperative, but Josephs said he hopes to capture more local trucking traffic over time.

Mark Buckner, chief business development officer at Dalton Utilities, said the new CNG station "gives Dalton a unique asset that surrounding communities do not have." Buckner said the availability of CNG "could be the deciding factor behind whether or not companies choose to develop in Whitfield County."

Contact Dave Flessner at or at 757-6340.