Natural Gas Vehicles: A Viable Solution or Just Another Pipe Dream?

Natural Gas Vehicles: A Viable Solution or Just Another Pipe Dream?

A Look at One of the Alternatives To Petroleum

An alternative to petroleum-based fuel is urgently needed to address climate change concerns, so the search is on for a car that is not only environmentally friendly, but also something that can be easily adapted into our everyday routines. One alternative of increasingly interest, which has led to a few instances of fleets making a switch, is NGVs or natural gas vehicles.

For those unfamiliar with this technology, the vehicle in question can run on compressed natural gas (which is methane stored at high pressure) or liquified natural gas (which is usually methane in a liquid form). Originally, natural gas can come either from the same places where oil deposits are found in nature or it can come in the form of biogas (or renewable natural gas), which is created from landfills and wastewater. It’s stored like any other gas in cylinders and can be transported through dedicated pipelines.

cng tank,storage,trade-offs

Tanks A Lot (of room)

The reason why NGVs are becoming so appealing is that not only is natural gas a plentiful resource that we can produce domestically, but it is also a much cleaner burning fuel. According to the Environmental Protection Agency (via Consumer Reports), CNG can reduce carbon-monoxide emissions by 90-97% and nitrogen-oxide emissions by 35-60% when compared with gasoline. However, CNG’s aren’t completely environmentally friendly, and there is much controversy surrounding how it’s widely obtained; through hydraulic fracturing (or “fracking”), which can result in upstream emissions of methane if done incorrectly. The Department of Energy cites the Argonne National Library’s GREET model as stating that while natural gas does emit 6-11% less greenhouse gases than gasoline during it’s fuel life cycle, those emissions it does release are widely the result of production-phase fuel leakage. It’s also worth noting that while it may release less GHG’s than gasoline, it takes more natural gas to do the same job as gasoline because it’s less energy dense than gas. What this means is that if you were to purchase a NGV you’d have to have a bigger tank in your car and have to refill it more often than a traditional gasoline fueled car. However, the GREET model also shows that CNG’s produce around 20-45% less smog-producing pollutants and about 5-9% less greenhouse gas than gasoline powered vehicles, though recent studies are challenging the GHG reductions (though those findings are challenged in the latest California Air Resources Board analysis in its LCFS CA-GREET 2.0 model for measuring the carbon intensities of various fuels.

So, how exactly do NGVs stack up to electric vehicles? Let’s defer to a recent study from MIT, which stated that: “While both EVs and NGVs have significant infrastructure requirements, there are major differences in their relative efficiencies. An NGV does not have comparable efficiency gains relative to electrification via natural gas generation. In general, 1,000 cubic feet of natural gas, converted to electricity, yields 457 miles in an EV. This same 1,000 cf in an NGV would only have a range of around 224 miles.”

However, an article by Forbes contradicts this saying that a “four-door CNG taxi with a tank that can hold the equivalent of 15 gallons of fuel can get close to 300 miles on a tank. 200 miles is easy. Most mid-range and economy-level EVs like the Nissan Leaf get almost 100 miles on a charge.” At this point these contradicting studies could be the result of different methods of research or using different vehicles from each other. (Ed. Note: some of the confusion is comparing apples and oranges, in this case relative energy efficiencies with real-world functionality.)

Another strike against natural gas is the lack of infrastructure, high cost of storage, and lack of availability here in the U.S. While traditional gas stations are abundant, NGV fueling stations are few and far between due to the general lack

honda,civic, natural gas,cng,badge

A Badge of Honor

of demand with the DOE showing only 746 in the continental United States. Also, chances are if you do find a NGV fueling station, it’s only available to fleets belonging to companies like AT&T and UPS who use NGV’s.

However, there are companies and municipalities advocating for CNG. Honda is building a CNG gas station in Columbia, Ohio, in concert with Columbia Gas of Ohio, and some states have decided to use CNG to fuel their mass transit fleets. The Sun Tran transit line in Tucson, Arizona is fueled exclusively by CNG, and many transit agencies and other entities in the state of California has been using CNG powered buses also.

The bottom line with CNG vehicles appears to be this: We’ve got a ways to go before it becomes a truly viable option for all consumers. At this phase, while CNGs can be seen as better for the environment in some aspects, their lack of availability in the United States, paired with the shortage of public fueling stations makes them generally an impossibility for those who aren’t willing to the costly trouble of installing a home fueling station. Also, for consumers (other than fleet customers) there is only one model available, the compact Honda Civic. However, based on the dropping cost of natural gas, it’s potential to boost the American economy, and a growing concern for environmental health, it’s likely that CNG’s will pick up steam sooner rather than later. Right now they may not be the most viable option for the average person, but it’s something that we could see become commonplace in the future.

Related Stories You Might Want to Check Out:

Road Test: 2013 Honda Civic Natural Gas

Electric Cars Compete with Natural Gas and Diesel for Green Car of the Year

Natural Gas

Electric Trucks, Hybrid Diesel Cars, Alt Fuel Vehicles

Electric Trucks, Hybrid Diesel Cars, Alt Fuel Vehicles

Ford Transit Connect ElectricBy Tom Bartley. The Advanced Clean Transportation (ACT) EXPO, May 4-6, 2011, at the Long Beach Convention Center had 42 on display and 25 ride-n-drive alternative fuel vehicles running on natural gas, propane, biofuels, hydrogen, and electricity. This is the largest conference of its type in the US this year, taking over from the dropped AFVI/Clean Cities annual conferences.

The conference included tours of the Port of Long Beach, Republic Services in the City of Gardena, L.A. Unified School District, L.A. municipal fueling, and Ryder’s Natural Gas Truck Rental. Each tour highlighted a major fleet fueling facility for natural gas (CNG and LNG) or propane. There’s nothing like an increase in fuel prices to get people thinking about alternatives. And there’s nothing like public awareness to get manufacturers’ thinking.

Keynote speaker, Dr. Kathryn Clay, Executive Director of the Clean American Transportation  Alliance, set the theme for the breakout sessions. We need all the possible solutions because there is no golden spike or silver bullet that will do it all. Vehicles and fuel have to be:

  • Available
    • Refueling infrastructure
    • Locations to match the vehicles that need it
  • Affordable
    • Sustainable vehicles, fuel, and operations with cost models that do not hinder business activity and personal travel
    • Elimination of imports that threaten economic, energy, and national security
  • Clean
    • Management of Fuel production hazards
    • Continuing air quality improvement to prevent premature deaths (currently estimated at 5600 per year in the Los Angeles basin)
    • Minimize green house gases that may be affecting climate change

Alternative fuels technologies have been pushing hard to deliver all these characteristics and have pressured traditional petroleum fuels to do likewise. Hybrid-electric cars and buses are now over 10 years old. Propane and natural gas engines have significantly improved. Hydrogen is starting anew.

Cleaner Hybrid Diesel Cars and Trucks

Diesel now offers more clean bangs. After being introduced in Paris in 1897, diesel vehicles have over 50% of the market in Europe. Led by GM, diesel cars and light-trucks had 10% of the US market in the 80’s, but they a reputation for poor reliability, high maintenance, and dirty fuel. I hated the smell of the exhaust and, as a mechanic; I hated the smell of the fuel and the dirty oily engines. Today is different. Diesel engines are robust at all levels; the exhaust is clean; engine and fuel seals have moved forward a few generations.

In the US, the sale of diesel passenger cars and light-duty trucks is increasing. Why? First, diesel is widely available and it’s efficient. Because of it’s volumetric and weight energy density, diesel fuel is the best we have for transportation. In his presentation during a ACT Friday breakout session, Alex Freitag, Director of Bosch Diesel Systems Engineering for North America, said that, for comparable vehicles and engines, diesel now holds a 30% fuel economy advantage over gasoline. 10% of that comes from the amount of energy per gallon. On one chart Alex compared a gasoline hybrid at 50 mpg with a diesel hybrid at 72 mpg. (It must be a Prius on steroids.) Because of the higher fuel economy diesel had lower CO2 emissions per mile. Furthermore, Alex indicated that there are additional improvements that will widen the gap. For over 100 years the Bosch Group has been a leader in supplying technology and components to the automotive industry.

The diesel efficiency improvements are possible because the exhaust cleanup is left to the converters, filters and traps. All this comes at the cost of a higher purchase price, but results in a lower life cycle cost of ownership. The breakeven point for direct costs of operations can be measured in months rather than decades.

So, diesel is available, clean, and affordable. What about imports? Over 50% of the US transportation diesel is imported, but that leaves a little under 50% that is domestic and biodiesel already offers some price advantages while continuing to advance in availability. Using less diesel fuel per mile is another way to reduce those imports.

Natural Gas Vehicles

The EXPO had 27 natural gas vehicles in the hall and 6 more in the ride-n-drive. Through the development of horizontal drilling and fracking the US is now considered to have the largest reserves in the world. There is enough to replace imported transportation oil and still have enough for heating and power generation.

Fleet owners realize that the price of natural gas is now detached from oil and looks like it will be stable for a long time into the future. A 52 cent per gallon rebate (cash) sweetens the pot for both the non-profit and for-profit organizations. The biggest variable cost is the electrical energy cost of compression. But if the compressor engine burned CNG, hmmmmmmmmmm.

One notable CNG display vehicle on the EXPO floor was the world’s first CNG emergency reponse vehicle by HME. This a new approach to reduce the cost of fire protection.

What’s missing? Infrastructure – As a fleet operator, you need to be concerned about range and refueling. We could use more public stations across wider areas. This also means more regional and interstate pipelines. The Wednesday tours showed that the thinking of the big central fleets is already on board, but the smaller operators have a hard time covering the cost of a station.

The Honda Civic GX CNG passenger car, one of the cleanest in America, offers excellent fuel cost for a slight premium purchase price. PHILL offers the affordable home compressor/refueler option. The public could use some more choices in competition with the GX to excite the market.


15 million vehicles around the world burn propane for fuel, not just for the tailgate bar-b-ques. The US has the world’s largest storage and the good news is that 60% of it comes from natural gas, thus, offering price stability detached from gasoline and with the 52 cent per gallon IRS sweetener. The liquid injector technology was a significant clean improvement for the engine and storage tanks. There were 6 vehicles on the floor and 6 more in the ride-n-drive. Propane provides 25% less energy content per liquid gallon than gasoline at a 35% less price.

Electric Trucks and Buses

One Proterra bus, one heavy-duty Balqon truck, one Smith delivery truck, and two light-duty (FCCC and Ford Transit Connect) vans were displayed on the EXPO floor.  The bus, the delivery truck, and an ALTe pickup were at the ride-n-drive. Notable is the Proterra battery-electric transit bus in daily service for Foothill Transit in Pomona, California. The bus probably has the largest battery pack in mobile operation. Even at 28,000 lbs curb weight, it still manages on less than 2 kWh per mile and a 10 minute charge time. It’s an efficient operation, quiet, but not really sustainable in low quantities at over $1million per bus and probably more for the 1.2 MW charge station.  Unknown is what happens when they get hit for $1.00/kWh demand charges in the middle of the summer. They may need a rather large battery pack at the charge station.

Hydrogen Fuel Cell Vehicles

There was a Honda FCX Clarity hydrogen sedan on the EXPO floor; another Clarity, Chevy Equinox, and Kia Borrego SUV at the ride-n-drive. Noticeably absent was one of the 100 Toyota prototypes. These vehicles are being pushed by the California Fuel Cell Partnership (CAFCP) along with the hydrogen highway concept.  The concept is now one of local clustering connected by one or two stations in between. It’s actually working better than E85 stations in California.

No E85 Ethanol Presence

E85 didn’t have a presence at this EXPO. Outside of Iowa the biggest advantage is replacing imported oil with domestic ethanol. The energy balance of production leaves a lot to be desired, but we are replacing 10% of the gasoline with the E10 we buy at the pump today. Actually, it’s a bit less because of the lower energy content of ethanol.

The EXPO had over 1300 attendees, 300 more than expected as high petroleum prices have fleet managers eager to use cleaner and less expensive alternatives. The show producers Gladstein, Neandross & Associates (gna) did a great job hosting the event.

Natural Gas fuels CNG Buses, LNG Trucks, Alt-fuel Fleets

By John Addison (12/22/07)

Amaranth Advisors is a hedge fund that keeps making front page news. It is trying to explain to investors how it lost $5 billion in one week betting that natural gas prices would rise. Gas prices fell. $5 billion is gone. Amaranth Advisors is a hedge fund with a trader who forgot to hedge.

The bet could have gone the other way. One good hurricane to disrupt supplies would have spiked prices upward, as would an early cold weather snap to fire up millions of heaters. The bad bet is understandable. In the long term, natural gas prices are likely to return to prices at the start of this year, double what they are now.

Natural gas is likely to become the number one source of energy globally, surpassing current number one – oil. Natural gas is the fuel of choice for modern electric power plants, being cleaner than coal.

Natural gas helps achieve energy independence because it is not refined from oil. Over 90% of the natural gas used in the USA is from North America. Natural gas burns cleaner than gasoline, ethanol and biodiesel. Natural gas is popular with cities and other fleets with low-emission programs. The next time you take a taxi at an airport, it may be running on natural gas. These vehicles get priority at airports.

Natural gas is about 90% methane; the molecule is CH4. The molecule is four hydrogen atoms and one carbon. Natural gas is primarily hydrogen. In fact, most early adapters of hydrogen vehicles are natural gas fleet owners. Most vehicles use compressed natural gas (CNG). Heavy trucks that need more fuel for long distance may use liquid natural gas (LNG). It is expensive to keep natural gas so cold that it stays in liquid form, so CNG is the most popular approach.

There are about ten million natural gas vehicles in operation globally. There are about 150,000 natural gas vehicles in the USA. These vehicles consume 238 million gasoline gallon equivalents. That amount has doubled in only five years. CNG vehicles are popular in fleets that carry lots of people: buses, shuttles and taxis.

Natural gas prices have not been increasing at the speed of gasoline and diesel prices. The fuel price advantage is causing some to switch to CNG. Diesel vehicles are getting more expensive with tough 2007 emission standards. Some diesel makers state that EPA 2010 emissions are impossible. These statements are scaring some to switch to CNG. The federal government offers tax credits up to $40,000 for large natural gas vehicles, creating an added incentive.

Some governments are going beyond incentives and mandating the use of CNG. Seoul, Korea, plans to allow only buses that run on CNG, beginning in 2010. The measure is intended to reduce pollution. Currently, 2,798 of Seoul’s 7,766 registered city buses are CNG buses, and the rest are diesel-powered vehicles.

Since 1993, LAWA has been buying vehicles which reduce smog-forming emissions and which reduce greenhouse gases. LAWA now has 490 alternate-fuel vehicles at the four airports which it operates – LAX, Ontario International, Palmdale and Van Nuys. At LAWA, I met with Dave Waldner, Alternative Fuels Fleet Manager, who has been reducing emissions for over 13 years. He explained that early success started with compressed natural gas (CNG) in vehicles in 1993. Then liquid natural gas (LNG) was used in transit buses. LNG provided for longer-range than CNG. With oil prices increasing over 50% annually, CNG has proved to lower fuel cost. LAWA has secured very favorable long-term contracts, paying a little over $3.00 per thousand cubic feet of natural gas. CNG is also available to the many independent fleet operators and individuals using airports. LAWA encourages independent operators to use clean vehicles that use CNG and hydrogen. Clean Energy operates public CNG stations at LAX and Ontario.

Taxi fleets were early adopters of CNG. They received the strong revenue incentive of getting first priority in passenger pick-ups. They also receive a tax credit of $6,000 per CNG vehicle. There were 156,000 taxis operating in the United States in 2004, less than 2% of these vehicles were natural gas vehicles. The growth opportunity is substantial.

It has not been easy for many other early adopters of CNG vehicles. Individual automobile owners painfully experienced different fueling stations using incompatible pressures and nozzles. Fleet managers spent millions building new facilities to meet fire and safety standards. Heavy CNG vehicles often lack the acceleration and range of their diesel counterparts. Storage makes the vehicles weigh more. In hot weather fills can be slow. Fleet managers have faced hundreds of angry riders, when their natural gas was not delivered as scheduled. Natural gas prices fluctuate dramatically, making long range budgeting difficult.

Several of these problems have been resolved. There are now nozzle and pressure standards. There are more CNG stations and they are easy to find on maps and the Internet. Storage tanks are lighter, reducing the extra vehicle weight and improving performance.

Natural gas is not a panacea. To deal with our climate crisis and free us from depending on oil, many see the answer in a portfolio of energy sources rather than one “silver bullet.” The portfolio could include electricity, next generation biofuels, hydrogen and natural gas.