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.
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
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.
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