Environmental Benefits of Natural Gas Vehicles
Energy security, fuel diversity, reduced emissions, and lower long-term costs are reasons why encouraging greater use of natural gas as a transportation fuel is a smart choice for fleets and consumers. The U.S. is the world’s top producer of natural gas and given this abundance, it will soon be a net exporter, helping other countries increase their energy security. It makes sense to build on the many benefits that this domestic resource provides by expanding its use in transportation. The transportation sector is heavily reliant on petroleum fuels and with respect to heavy duty applications, there are few viable alternatives to power fleets other than natural gas.
Natural gas facts with regard to emissions include:
Natural gas reduces tailpipe carbon dioxide (CO2) emissions relative to gasoline and diesel fuel by 26 – 27%, respectively, simply because it is less carbon intensive than gasoline and diesel. Natural gas consists mostly of methane (CH4) with a chemical makeup that is 4:1 hydrogen to carbon (gasoline has 8 carbon atoms and diesel has 16).
On a well-to-wheels basis (WTW), natural gas reduces overall GHG emissions by 11 to 17% compared to diesel or gasoline (see below).
Today’s natural gas engines emit significantly less particulate matter and nitrogen oxides (NOx) than engines produced just a few years ago. New low-NOx natural gas engines reduce ozone-forming NOx emissions 90% lower than the current EPA standard.
Renewable natural gas (RNG) is increasingly being used by fleets who wish to reduce their emissions even further. RNG is produced by landfills, waste-water treatment facilities, and through animal and crop waste systems. RNG is classified by the EPA as an advanced biofuel and a cellulosic biofuel under the Renewable Fuel Standard. RNG can reduce WTW GHG emissions by as much as 80 – 115% depending on the source compared to petroleum fuels.
Well-to-wheels comparisons of emissions related to natural gas versus gasoline and diesel vehicles can produce varying results given a variety of complex factors, including assumptions concerning upstream methane emissions and fuel efficiency of the particular vehicles being considered. WTW analysis indicates that NGVs, when fueled with conventional compressed natural gas, provide a 17% reduction in greenhouse gases compared to diesel fueled vehicles (assumes 25 GWP factor for methane, 100-year time-frame, 7% fuel economy penalty for natural gas).
Recent studies and analysis suggest that additional reductions from the natural gas system can be cost effectively implemented and that much of the emissions that is occurring is the result of super emitters or outlier sources. EPA has a number of new regulatory requirements that will also further reduce upstream natural gas emissions.
New technologies and innovation are also bringing advancements in natural gas engines. Cummins Westport is installing closed-crank cases on newer model year engines which will further reduce vehicle methane emissions by 70%. NGVs operating in Europe already use this technology and it is expected to be adapted to most heavy duty natural gas engines in the near future. Manufacturers of light duty natural gas vehicles can further reduce GHG emissions by taking advantage of natural gas’s near 130 octane rating and optimizing engines to fully benefit from these properties. Optimized natural gas engines could provide efficiency advantages that exceed gasoline and even diesel engines in the
As mentioned earlier, renewable natural gas (RNG) is growing in the NGV marketplace. Today, it is estimated that 20% of all natural gas used for on-road transportation fuel is RNG. Based on this estimate, natural gas used in transportation is already providing an overall reduction in GHG emissions by about 30% (assumes CA LCFS LFG CI numbers, 7% fuel economy penalty, and 100-year GWP time frame).
Natural Gas Vehicles Deliver Reduced Emissions for Fleets and Consumers
Today’s natural gas vehicles fueled by conventional natural gas deliver between 11 and 17% lower GHG emissions than similar diesel and gasoline powered vehicles.
Considering that 20% of the fuel used in natural gas vehicles is renewable natural gas, this benefit grows to 30%.
Future efforts to optimize natural gas engines and vehicles will increase efficiency and deliver additional emission reductions by taking advantage of natural gas’s superior attributes.
Medium and heavy duty natural gas vehicles will provide the most significant benefits because solutions are available today to address greenhouse gas emissions in a market segment where few other options exists.
Increasing the use of natural gas vehicles will help the U.S. meet its commitments under COP21, including achieving greenhouse gas emission reductions of 26-28% below the 2005 level in 2025.
Renewable natural gas provides a pathway to significantly greater emissions offsets. Today, fleets already have the option of contracting to displace a portion of the conventional natural gas they use, or they can go 100 percent renewable natural gas. Fleets using 100 percent RNG can offset greenhouse gas emissions by 80 – 115%.
The Benefits and Opportunity of Natural Gas Vehicles
As the largest producer of natural gas in the world, there is a tremendous opportunity today for the United States to use this key domestic energy source as a transportation fuel. Natural gas is an inherently clean-burning fuel that is helping fleets across the country lower their bottom line and achieve their sustainability goals. Recent announcements in the marine, rail, and heavy machinery sectors indicate they are now transitioning to natural gas as well. The expanded use of natural gas as a transportation fuel also holds a number of important policy benefits. With 33 states producing America’s abundant natural gas, extending the use of this key energy source is important to each state’s economy, air quality, and energy security. States can play an important role in promoting the use of natural gas for transportation and in growing the marketplace for natural gas vehicles (NGVs).
Transportation fuel consumption in the U.S. equals 66 Bcf/day, representing a tremendous opportunity for natural gas to displace a percentage of diesel and gasoline. Current growth areas for NGVs include the heavy duty regional trucking, refuse, transit, the medium duty package delivery and service markets, and oil & gas operations. Heavy duty long haul trucking, marine, rail, and heavy machinery are beginning to gain momentum and represents an even greater opportunity for reduced costs and emissions.
The natural gas shale revolution has dramatically changed the U.S.’s world position and enabled the U.S. to become the world’s top natural gas producer. Supplies of natural gas are at record high levels, and the Potential Gas Committee’s (PGC) most recently estimated supplies at 2,853 Tcf. This means there is a 90 plus year supply of natural gas that continues to grow. More than two thirds of the U.S. States supply this abundance.
Natural gas is an odorless, colorless, non-toxic, and non-corrosive source of energy that is abundant and produced in the U.S. When used as a fuel for vehicles it is cost effective, clean, and quiet, providing an excellent alternative to gasoline and diesel. Natural gas is used as a vehicle fuel in two forms, compressed natural gas (CNG) and liquefied natural gas (LNG). Increasing the use of domestic natural gas for transportation provides economic benefits and improves our energy security by displacing demand for imported oil.
Natural gas is not tied to world oil prices, creating a low-cost advantage that will last for decades to come.
Recently, CNG and LNG cost approximately $1.50 to $2.00 less than gasoline and diesel, although this difference is currently averaging about $0.40 - $0.75 less than diesel fuel.
The commodity cost of natural gas as a percent of the total delivered fuel cost is much less than for gasoline or diesel, providing stability in the total fuel price for CNG and LNG.
The incremental prices for NGVs and conversions are decreasing, and innovations in CNG and LNG fuel tanks will help to lower these costs further.
Natural gas consists primarily of methane (CH₄) and burns almost completely.
NGVs generally emit 11–17 percent fewer greenhouse gas (GHG) emissions than comparable gasoline and diesel vehicles on a well-to-wheels basis.
When replacing older trucks and heavy duty vehicles:
Nitrogen oxides (NOx) emissions are reduced 75–95 percent; and
Particulate matter (PM10) is reduced 95 percent for engines prior to 2007.
Natural gas is lighter than air and so rises and disperses quickly and does not damage surrounding ecosystems and water systems if vented.
New natural gas heavy duty engines produce NOx at levels approaching zero emission vehicles.
NGVs are 80–90 percent quieter than comparable diesel vehicles.
NGVs meet or exceed EPA standards for GHG and air quality.
Success Factors for NGV Market Growth
Many factors are involved in growing the NGV market, but key components are vehicle availability, fueling stations and government incentive programs. There are many options in the medium and heavy duty vehicle market for CNG and LNG vehicles, but each carries an incremental cost that must be overcome.
Over the past two years, fueling stations for CNG and LNG have grown 17%. This station growth continues due to the demand for NGV fueling is growing. More stations and vehicles per stations are needed, however, for a vibrant NGV market.
What States Can Do to Grow the NGV Marketplace
While natural gas is more cost effective than most other transportation fuels, the incremental cost of vehicle and costs to build stations are significant, justifying the need for incentives. Unfortunately, at the federal level only electric vehicles receive tax incentives. In many cases, states are stepping up to support the opportunity for NGVs by providing incentives. Needed policies that the states can provide include:
NGV grants and/or tax incentives;
Excise tax and method of sale based on gasoline and diesel gallon equivalent (GGE and DGE) units;
Incremental sales tax exemption—fleets should not have to pay more tax to buy a vehicle that is better for the environment than gasoline or diesel vehicles; and
Incremental weight exemption for heavy duty NGVs (add 2,000 lbs. to allowable limit).
The U.S. and its states are fortunate to have a vast natural gas resource. The natural gas industry provides jobs, revenue to land owners and governments, broad economic benefits to communities, and the investment of the industry’s employees in the state and their communities. The expanded use of this domestic resource will further aid states by reducing fueling costs and emission of harmful pollutants, and by providing greater energy security.
For more information, Contact:
Sherrie Merrow, NGVAmerica Chair, State Government Advocacy Committee, .
Jeff Clarke, NGVAmerica General Counsel & Dir. Regulatory Affairs, .
Make a Bold Impact on Air Quality Today
Allocating funds to deploy low-NOx natural gas vehicles provides the best way to deliver immediate and cost-effective NOx reductions and air quality benefit. Nearly 40% of Americans are exposed to unhealthful levels of ozone and particulate pollution. Volkswagen’s $2.9 billion Environmental Mitigation Trust fund provides each state an incredible opportunity to make an immediate and tangible impact on air quality by targeting medium- and heavy-duty vehicles, the leading source of these toxic air contaminants in almost every metropolitan area.
NVGs Offer the Cleanest Heavy-Duty Truck Engines in the World
Natural gas medium- and heavy-duty engines provide unmatched reductions of smog-forming emissions of nitrogen oxides (NOx). In 2015, a revolutionary natural gas engine was certified by the U.S. Environmental Protection Agency and California Air Resources Board to a level 90% below the EPA’s current exhaust standard and 90% below the cleanest diesel engine. A truck with this engine has an emission profile equivalent to that of a heavy-duty battery electric truck.
Dollar-for-Dollar, NGVs Deliver the Most Cost-Effective NOx Emissions Reductions
The calculations shown below assume the deployment of the cleanest commercially available model for each application. Funding natural gas vehicles will lead to the largest total reduction in NOx emissions.
NGVs are Commercially Available Today Across All Applications Qualified for Funding
NGVs are commercially available from traditional truck and bus OEMs with established sales and service networks. Retrofit and repower options are also available from a variety of manufacturers.
• Cement Mixer
• City Delivery Truck
• Conventional Van
• Dump Truck
• Fuel Truck
• Heavy Semi Tractor
• Large Walk In Van
• Motor Coach
• Rack Truck
• Refrigerated Van
• Refuse Truck
• Single Axle Van
• School Bus
• Shuttle Bus
• Transit Bus
• Tow Truck
• Utility Truck
Natural gas is a clean, low-cost, and domestically abundant transportation fuel.
Currently, natural gas prices can be $0.75 to $1 or more lower than diesel at the pump, with a firm price advantage expected to remain for decades as shown in the chart above.
Beyond the fuel-price differential, the pump price of natural gas remains relatively stable for two reasons. First,it is domestically sourced. Second, the commodity cost of natural gas only makes up 23% of the pump price so price fluctuations have minimal impact.
In contrast, approximately 60% of the price of diesel fuel is impacted by the market cost of crude oil, which is largely sourced from politically unstable, high-conflict regions. When crude oil prices increase, diesel prices follow suit which can lead to significant swings in a fleet’s fuel costs.
Volkswagen EMT Funding Recommendations
Fund alternative fuel vehicle projects that cost effectively maximize NOx reductions for both public and private fleets
Provide higher funding levels for medium and heavy-duty engines that deliver NOx reductions greater than current EPA standards
Target funding for technologies that have demonstrated lower in-use emissions
Prioritize funding for commercially available products and projects that are ready to begin
Stay flexible in plans and leverage private investment to stretch dollars and get more alternative vehicles on the road
Natural gas vehicles can fulfill all of these recommendations today!
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