The U.S. Environmental Protection Agency (EPA) and the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) have this week jointly finalized standards for medium- and heavy-duty vehicles that will improve fuel efficiency and cut carbon pollution, add to energy security and stimulate manufacturing innovation. NGVAmerica, the U.S. trade association for natural gas vehicles (NGV), sees positive outcomes for the natural gas for transportation sector.
“NGVAmerica has worked closely with EPA and NHTSA over the past three years to ensure that the strong benefits of natural gas vehicles were reflected in developing a final rule,” said NGVAmerica President Matthew Godlewski. “Cleaner and greener heavy-duty trucks are the goal of this rule-making and we are confident that it will result in continued opportunities to use more natural gas to meet our country’s transportation needs.”
Commenting further, Godlewski points out that although further analysis of the new standards is needed before a full evaluation can be made, many of the recommendations put forward by NGVAmerica have been adopted, for instance, fuel consumption will continue to be calculated according to tailpipe CO2 emissions, which allows fuels to be compared on a one-to-one basis (see “Phase 1 continues …” below); and, the standards have continued to allow for compliance with methane or nitrous oxide standards by over-complying with CO2 standards.
The impact of increasing the Global Warming Potential (GWP) from 25 to 34 has yet to be fully assessed but Godlewski suggests any negative impact upon the benefits of natural gas fuelled vehicles will be small.
Heavy-duty trucks collectively make up the biggest increase in the U.S. transportation sector in terms of emissions and energy use. These vehicles currently account for about 20 percent of GHG emissions and oil use in the U.S. transportation sector. Globally, GHG emissions from heavy-duty vehicles are growing rapidly and are expected to surpass emissions from passenger vehicles by 2030.
The vehicle and engine performance standards would cover model years 2021-2027, and apply to semi-trucks, large pickup trucks and vans, and all types and sizes of buses and work trucks. When the standards are fully phased in, tractors in a tractor-trailer, for example, will achieve up to 25 percent lower CO2 emissions and fuel consumption than an equivalent tractor in 2018.
NHTSA and EPA have worked together to harmonize their standards under this program, also working closely with the State of California’s Air Resources Board.
For each category of HDVs, the standards will set performance targets that allow manufacturers to achieve reductions through a mix of different technologies, not just advancements in engine technologies, and generally leave manufacturers free to choose any means of compliance. For tractor standards, for example, different combinations of improvements like advanced aerodynamics, engine improvements and waste-heat recovery, automated transmission, lower rolling resistance tires, and automatic tire inflation can be used to meet standards.
Phase 1 continues for Natural Gas Engines and Vehicles
For natural gas engines and vehicles, the combined Phase II rulemaking 1 by EPA and NHTSA is designed to regulate two separate characteristics of heavy duty vehicles and engines: GHGs and fuel consumption, according to the prepublication version of the standards issued August 16. The document states: “It recognises, for example, a natural gas vehicle that achieves approximately the same fuel efficiency as a diesel powered vehicle will emit 20 percent less CO2; and a natural gas vehicle with the same fuel efficiency as a gasoline vehicle will emit 30 percent less CO2. Yet natural gas vehicles consume no petroleum. The agencies are continuing Phase 1 approach, which the agencies have previously concluded balances these facts by applying the gasoline and diesel CO2 standards to natural gas engines based on the engine type of the natural gas engine. Fuel consumption for these vehicles is then calculated according to their tailpipe CO2 emissions. In essence, this applies a one-to-one relationship between fuel efficiency and tailpipe CO2 emissions for all vehicles, including natural gas vehicles. The agencies determined that this approach will likely create a small balanced incentive for natural gas use. In other words, it created a small incentive for the use of natural gas engines that appropriately balanced concerns about the climate impact methane emissions against other factors such as the energy security benefits of using domestic natural gas.” (Pages 104-105)
NGV Global awaits further commentary on the new standard from it’s affiliate, NGVAmerica, and from sponsors and members in North America.
1 In August 2011, the agencies finalized the Phase 1 standards for new MDVs and HDVs in model years 2014 through 2018.
(Source: U.S. Environmental Protection Agency)