Here at NWMotiv, we’re all automotive enthusiasts. Being true automotive enthusiasts however don’t necessarily mean that you’re only into fast cars or exotic cars; people like myself just love cars in general and the technologies behind them. Among the prevailing automotive technologies in recent years are the use of alternative fuels, such as hybrids and biodiesel. While these fuels don’t really peak the interest of most automotive enthusiasts who like cars that actually go fast and/or don’t run out of batteries after a hundred miles, there is one type of fuel that has been around for decades, but hasn’t really taken off until recently: compressed natural gas, or CNG.

CNG has its roots during the 1970s fuel crisis. Most of us who frequent NWMotiv weren’t even alive (or self-aware) in the 1970s, but in short, the big oil producing countries put strict limits on the amount of oil being exported and thus fuel costs skyrocketed well past anything we’ve seen in recent years and ungodly long lines at the gas pump. It was during this time that the search for alternative fuels truly began, among them being natural gas, which is essentially methane. As it turns out, North America, particularly the United States and Canada, contains some of the richest deposits of natural gas in the entire world, making North America analogous to the Middle East and its oil.

So why didn’t natural gas take off at that point? Well, in order for natural gas to be used to power a vehicle, it needs to be either compressed or cooled down to a liquid. Heavy refrigeration systems are obviously not very practical for light and medium duty applications (such as your daily driver), so compressed natural gas would be the way to go. However, being in a gaseous compressed state, natural gas has to be stored in cylinders (much like the propane that powers your barbecue or helium cylinders to inflate balloons), and the only available cylinders back then were made of steel. Not only were these steel cylinders heavy, but they also created safety concerns. What if your car got into an accident? Would the tank explode? How do you prevent leaks? Another issue was that CNG wasn’t able to provide the same amount of power and torque as gasoline. These and other concerns prevented CNG from becoming popular outside of larger applications such as city busses.

Fast forward 30 or so years to today. Gasoline prices are starting to rise again, and while they’re not as high as they were only a couple years ago, tragedies such as the oil spill in the Gulf of Mexico are a sad reminder that the fuel we’re using is not only hurting the environment, but is also not a renewable resource that we can depend on for decades to come. Hybrids and electric vehicles already exist, but each of these has their own caveats. For example, hybrids work fine for commuting, but when you actually need power and torque (such as with a work truck or a racing application), they just aren’t going to cut it. Electric vehicles can produce good power, but the batteries are still very heavy and the vehicle’s range is extremely limited. Biodiesel was thought to be a good alternative for a while, but overall it caused other issues in that raising crops for biodiesel often took away from food crops and the environmental impact of processing the crops for biodiesel would often negate its positive effects. So what’s left: an age-old friend that goes by the name of CNG.

The main concern for using CNG back in the 1970s was safety. While safety is always a concern, it’s much less of a concern now that technology has provided solutions. Instead of the CNG being stored in heavy steel cylinders, CNG is now stored in lightweight, ballistics material (think of real carbon-kevlar that the military uses, not your $400 Seibon hood) that must endure strictly regulated EPA and NHTSA tests. These tests ensure that the cylinders won’t leak, can withstand impacts, and if punctured will not result in an explosion. Another main concern was that CNG wasn’t able to produce the same amount of power and torque as gasoline. This has also been solved since all cars these days are powered by a computer, which was definitely not the case back in the 1970s. Through ECU tuning, CNG fueling systems can be tuned properly so that they can easily match and often exceed the amount of power and torque that gasoline produces. After all, methane is 129-130 octane, which is something that should be attractive just about any automotive enthusiast who likes fast cars. Just recently, Volkswagen raced CNG-powered Sciroccos at the 24-hour Nürburgring endurance race on May 12th, and a CNG-powered 650hp hot rod was recently showcased at an industry trade show.

With all of this in mind, we also have the environmental and economic impacts of using CNG as opposed to gasoline. Currently, CNG is typically 40% less expensive than gasoline, with pumps in the Seattle area currently selling CNG at $1.89 per gallon. Compare that with $3.19 per gallon for 92 octane at Chevron, and doing the math is quite easy. Granted, the demand for CNG isn’t as high as gasoline, thus keeping costs down, but since North America has more natural gas than just about everywhere else in the world, costs aren’t likely to rise like gasoline. On top of the natural deposits of natural gas, natural gas is also produced by decaying trash and by dairy farms (well, the cows specifically), and each of these can be harnessed to easily produce more natural gas for fuel, making natural gas a renewable resource. In fact, a group at Western Washington University has already used natural gas produced from a local farm to power one of their project vehicles, hopefully with more to come. CNG also produces on average 30% less greenhouse gas emissions than gasoline. This obviously isn’t as clean as a full electric vehicle, but it’s definitely a step in the right direction.

So why aren’t we all just converting to CNG now? The biggest hurdles to this have to do with both economics and safety regulations. The EPA requires certifications for vehicles to use CNG on the street. These certifications have specific emissions and safety requirements, and thus are not available for each and every vehicle model. So, if your car does not have a current EPA certification, it’s not allowed on the street. You can however use CNG without EPA certs for off-road vehicles, but then comes the other hurdle: cost. While the fuel itself is inexpensive, the components and labor to convert a vehicle to CNG are not cheap. The CNG cylinders themselves are very expensive due to the safety procedures they must endure, and we all know that carbon-kevlar isn’t cheap in general.

Thus, the big push for CNG currently is with large vehicle fleets, such as taxi companies, municipalities, large corporations, and any company that has to haul a lot of cargo. For example, all UPS delivery trucks have been powered by CNG for quite some time now, and just about every garbage/refuse truck that you see on the road today is powered by CNG. Taxicabs and shuttle buses that service Seattle-Tacoma International Airport are also converting to CNG, since the Port of Seattle has a mandate out that requires all public transportation servicing the airport to be powered by alternative fuels, and you simply cannot fit very much luggage in a Toyota Prius. Large vehicle fleets also have the advantage of being able to benefit from current federal and state tax incentives: when purchasing three or more new vehicles to be converted to CNG, the purchases become exempt from state sales tax and each vehicle receives a federal tax credit, the amount based on the weight of the vehicle being converted. Currently legislation in the U.S. Congress as part of the American Power Act is hoping to double the current tax credits for CNG-powered vehicles in order to help free our dependence on foreign fuel sources.

The fact is, CNG is here and is here to stay. How long or how widespread it becomes is going to be up to a lot of people: from local business owners to the lawmakers in Washington D.C. If you’re an automotive enthusiast like myself, the thought of using an alternative fuel to get equal or better performance is quite exciting, and I hope that after reading all this, you’re just as excited about CNG as I am. As always, please feel free to post up with any questions.

Some links to more information:

WorldCNG — CNG Conversion Services

Puget Sound Clean Cities Coalition — Promoting alternative fuels and a cleaner environment for the Puget Sound region

Pickens Plan — Supporting CNG use in fleets and heavy duty vehicles

CNG Now — Freedom from foreign oil

NGVs Now — Driving America’s Future