T
he future of vehicles may no longer be a flying car, but it could be something even greater: reducing America's dependence on foreign oil because of the increase in availability of natural gas.
Compressed natural gas is one of many alternative energy sources that are beginning to take off, John Kimball, the director of business and programs at Helman Composite Machinery, said. Helman designs and manufactures the carbon fiber containers for CNG vehicles in Taneytown.
CNG is one of the byproducts of hydraulic fracturing, also known as fracking. Another byproduct of fracking is liquefied natural gas, which is made from purifying natural gas and cooling it so much that it turns into a liquid.
Of the two, CNG is leading the market. According to the U.S. Department of Energy, there are 585 public compressed natural gas refueling stations around the country, compared to 32 liquefied natural gas stations.
At the moment, there are several horses in the energy race, Kimball said. However, because of the wealth of natural gas at the moment due to fracking on the Marcellus Shale paired with the environmental benefits, Kimball said he believes CNG will take off.
The principal emission for CNG tanks is water vapor, so it's environmentally friendly, he said.
"I believe the industry is seeing that compressed natural gas is the horse that's in the lead," he said.
However, the process of fracking is a bane to environmentalists in and of itself. There's the potential for contaminating ground water, depleting fresh water, and surface contamination from possible chemical spills among the concerns.
Henry Jacoby, a Massachusetts Institute of Technology professor and co-author of several studies focusing on shale and natural gas production, trade and use, said to remember fracking accounts for about one-third of the total natural gas produced in the United States.
"What's dramatic is the fact that gas has gone from almost zero to one-third, but it's still only one-third of the total," he said.
Overall, he said the emissions saved were nothing to write home about but were lower than using gasoline, which does make compressed natural gas more environmentally friendly.
When weighing the benefits of compressed natural gas, its low carbon emissions were a reason for Montgomery County to get on board.
Montgomery County purchased a fleet of its Ride On buses that run on compressed natural gas about 12 years ago, the chief of operations for Ride On, Steven O. Wells, said. About three years ago, 120 garbage trucks were converted to CNG as well.
The carbon emissions and savings on gas are a trade-off for the county. There are currently 85 CNG buses in the fleet, which the county is in the process of replacing due to their shelf life.
A typical diesel bus averages between 14 to 15 years before it is replaced. However, because the fuel tanks have a fixed life at about 12 years, it's more cost effective to replace the entire vehicle than it is to just replace the CNG tanks.
Current federal requirements for CNG tanks have a minimum of a 10 year shelf life, and a maximum of 25, Kimball said. When designing and producing carbon fiber tanks, Kimball said most producers are looking for a 20-year lifespan.
Wells said the investment into the buses is high: He estimated between $500,000 and $550,000 per bus. But the cost to fuel is much cheaper. According to April data from the Department of Energy, diesel averaged at $3.58 per gallon, while CNG cost $2.10.
CNG tanks are filled with pressurized gas, which can be highly explosive. In the last 12 years, Wells said there has never been a problem where the tanker has been breached. Safety standards help that, he said. Kimball said there are rigorous federal standards Helman must meet in the design stages of CNG prototypes, which makes the possibility of a tank exploding minimal.
For buses, the tankards sit on top of the bus. For the garbage trucks, it sits behind the cab of the truck, in between the dumping mechanism, Robin Ennis, the chief of solid waste collections at Montgomery County, said.
Jim Harris, the managing director of Helman, said that it pays off to find a lighter but more expensive tank for the vehicles.
"You can pay a little bit more for this component [carbon fiber] but drive down your cost of running the vehicle, then you're going to get your payback and return on investment quickly," he said.
Ennis, who helped choose and organize Waste Management fleets to convert to CNG, said the county ended up saving money by using the new technology. While custom-made CNG vehicles cost an estimated $30,000 to $50,000 more than their diesel counterparts, there were other factors that offset the cost.
The 2009 stimulus package offered a $32,000 tax credit toward any purchase of an alternative fuel vehicle.
"Combined with the lower cost of fuel and the tax credits, the county actually saved a million dollars the first year," she said.
Honda currently makes a compressed natural gas car, which starts at $26,300. Harris said in the future, he thinks cars will cease to use petroleum as their main fuel source. All-electric cars could take off. Or an electric-CNG hybrid, he said.
"[CNG] is going to probably end up being the primary fuel they're going to use," he said.
Christopher Rice, the manager of the Clean Cities program for the Maryland Energy Administration, said in reality, it depends on what duty cycle a vehicle is in. A duty cycle, which means what kind of vehicle it is and how far it will be traveling, determines which form of alternate energy is the most advantageous. For instance, running an 18-wheeler truck on any form of electric probably wouldn't be successful because "you get more bang for your buck" with electric vehicles in stop and go traffic, he said.
"It's good to match duty cycles with the correct technology," he said.
The state recently awarded 13 vouchers of up to $20,000 to commercial entities who wish to purchase compressed natural gas vehicles. The voucher program was the first for natural gas, similar to Maryland's tax credit for electric vehicles.
"One of the reasons why we're talking about [natural] gas is that the economics behind natural gas in the transportation sector has gotten a lot better. People are actually seeing a full return on investment with the price difference between natural gas and diesel fuel," Rice said.
It hasn't caught on in the way the electric vehicle market has because for commercial vehicles, diesel is a more mature technology. Diesel is one of the oldest forms of transportation possible, meaning all the kinks have already been worked out, he said.
But all of the emerging energy alternatives are part of a maturing field, he said, which includes propane, biodiesel, hydrogen and electric vehicles.
Ennis said in her experience, she hasn't been able to find the problem with CNG yet, other than the lack of refueling stations. In 2004, it cost the county $3.2 million to set up the bus refueling station, according to public information officer Bonnie Ayers. Until gas stations start offering CNG, it will continue to be a chicken or the egg problem, she said.
Kimball agreed, but thinks all the problems will solve themselves over time. When asked if natural gas could be the future of the residential vehicle market, Kimball said with the availability and tensions over petroleum, yes.
"I think it's a perfect storm," he said. "The answer is yes, we have to. We have to do this."
