Alternative Fuel: Renewable Natural Gas 101
January 15, 2020
Renewable Natural Gas, known also as RNG, biogas or biomethane, is methane captured from the decomposition of organic materials in agricultural, landfill and wastewater treatment facilities, cleaned and conditioned to strip out impurities, then injected back into the natural gas pipeline. RNG is chemically identical to conventional natural gas but made from renewable verses geologic sources. It is a renewable solution that leverages proven natural gas vehicles and accessible fueling infrastructure.
Renewable natural gas is the best solution for companies seeking transportation-related emission reductions to clean-up their scope 1 and/or scope 3 categories. Methane as a greenhouse gas is 25 times more potent than carbon dioxide and plays a critical role in reducing heat trapped by the earth. Throughout the RNG development process, methane emitted from farms, landfills and wastewater treatment facilities, no longer enters the atmosphere, but instead, is transformed into a renewable fuel. Thanks to methane capture during production and then use as a renewable fuel, renewable natural gas features the lowest carbon intensity of any fuel and therefore the highest lifecycle greenhouse gas emission reductions. Further, new engine technology offered by Cummins-Westport has achieved California’s lowest smog-forming emissions standard through near-zero nitrous oxide (NOx) emissions.
Renewable natural gas also presents a strong economic case for conversion. The federal Renewable Fuel Standard, California’s Low Carbon Fuel Standard and Oregon’s Clean Fuels Program were all created to expand clean fuel solutions and reduce transportation-related emissions, which for the third year is the largest contributor of poor air quality. In each of these programs, RNG is recognized as a renewable fuel solution, therefore qualifying for financial credits associated with use. Fleets switching to renewable natural gas, along with energy developers, share in a portion of the clean fuel credits, further reducing already low fuel costs.
Much like other alternative fuels, companies using renewable natural gas avoid taxation penalties placed on high-carbon fuels like diesel and qualify for a per-gallon retroactive tax credit that further reduces fuel cost. Grant programs for both infrastructure and vehicles remain an option as well to reduce incremental costs associated with a transition to natural gas.
Renewable natural gas is a drop-in fuel for existing natural gas vehicles and can therefore leverage benefits associated with that technology.
- Natural gas vehicles have proven performance across a wide array of market applications and vehicle classes. Cummins-Westport is a leading natural gas engine manufacturer that works with a variety of tank packagers and truck manufacturers to offer natural gas vehicles. They’ve built upon the first generation of engines, overcoming issues that originate with any brand-new technology, through the release of their Near-Zero engine platform in 2018. Fleets are running natural gas vehicles in many applications: trucking, refuse, school and transit – to name a few. Check out all proven natural gas technologies tracked by the Alternative Fuels Data Center.
- Natural gas vehicles have the luxury of utilizing an established infrastructure of 1,000+ public and private fueling stations, or, companies can build their own fast-fill or time-fill fueling station, at minimal investment. Time-fill fueling stations allow natural gas vehicles to refuel during idle periods, like overnight, reducing driver time and cost that typically would be spent refueling. Newer, modular systems can be installed for fleets wanting onsite fueling and take up the space of a parking stall, while easily expanding as your fleet and fueling needs grow in the future.
Renewable natural gas, although growing in supply, is somewhat limited outside California. This issue is improving as more RNG development sites come online, but still a consideration for conversion.
Natural gas vehicle prices are more expensive than diesel or gasoline equivalents, which is why federal and regional grant programs are so important. In many cases, these programs offset the incremental cost or significantly reduce it, but still a valid consideration. Further these vehicles have slightly less range diesel, but superior to other alternatives.
Maintenance is another consideration fleets must give thought to, well in advance of a conversion. Natural gas vehicles are easier and cleaner to maintain but have different maintenance intervals than diesel. If fleets choose to ignore manufacturer maintenance procedures, operating costs and performance deteriorate. If maintained according to specifications, maintenance costs compare to diesel and in some cases are lower.
Renewable natural gas presents the fastest pathway to significant emission reductions. Vehicle technology is proven, infrastructure developed and availability of renewable natural gas on the rise. Companies can obtain rich lifecycle emission benefits and obtain government financial support to do so. However, in regions without clean fuel incentives, the incremental cost of renewable natural gas and related natural gas vehicles may be challenging for fleets seeking the lowest cost fuel solution.