Policies and Incentives for Using Renewable Natural Gas as Vehicle Fuel

[caption id="attachment_2017" align="aligncenter" width="1024"] Urban buses powered by compressed natural gas (CNG) from Arlington Transit (ART), Crystal City yard, Virginia, USA[/caption]

Federal Policy and Incentives for Using Renewable Natural Gas as Vehicle Fuel

The federal Renewable Fuel Standard (RFS) requires obligated fuel suppliers to meet their Renewable Volume Obligation according to the annual volume of petroleum-based fuel they import or produce. One method of achieving this is for affected fuel suppliers to obtain renewable identification numbers (RINs) tradeable credits issued to renewable fuel producers for compliance as part of the RFS program.

State-Specific Low Carbon Fuel Standards

The low-carbon fuel standard (LCFS) was introduced in an effort to reduce carbon levels in vehicle fuels compared to conventional petroleum-based fuels such as diesel and gasoline. Low-carbon alternatives to carbon-rich fossil fuels include renewable fuels and cleaner fossil fuels such as CNG and LPG.

The low-carbon fuel standard introduced by the state of California strives to promote the production and use of cleaner low-carbon alternative fuels within the state. California's low-carbon fuel standard sets annual carbon intensity (CI) targets that vehicle fuel suppliers across the state have to reach each year. These carbon intensity target values are decreased over time, resulting in more low CI fuels such as RNG, natural gas, electricity, and hydrogen being used to power vehicles. Since the carbon intensity value of a fuel is based on the greenhouse gas emissions associated with its production and consumption over the complete lifecycle of the fuel in question, reducing these annual targets will ultimately contribute to a reduction in GHG emissions from the transportation sector. Fuels that have a CI value that is lower than the annual target stipulated by the low-carbon fuel standard generate credits, while those with higher CI values generate deficits.

In an effort to reduce the carbon intensity of transportation fuels in the state, the state of Oregon introduced the Clean Fuels Program, which has similar goals to California's Low-carbon Fuel Standard.

National Ambient Air Quality Standards

Any local jurisdiction that is unable to meet the National Ambient Air Quality Standards established by the US Environmental Protection Agency must develop a strategy to help them meet these standards, together with a timeline outlining when compliance with these standards will be reached. Urban areas that are unable to meet air quality standards for particulate matter (PM) and ozone must include strategies for reducing emissions in the transportation sector. One way to achieve this is to replace heavy-duty vehicles that run on diesel with vehicles that run on renewable natural gas, a low-carbon alternative fuel that has near-zero NOX emissions.

Converting Municipal Fleet Vehicles to Natural Gas

Municipal fleet vehicles, particularly waste trucks and buses, are typically some of the biggest fuel consumers and GHG emitters in urban areas. Many cities across the US have started to replace fleets that run on diesel with vehicles powered by alternative fuels such as RNG. In 2006, the Energy Secure Cities Coalition was formed, whereby eight major US cities (Atlanta, Charlotte, Indianapolis, Orlando, Rochester, Sacramento, San Diego, and West Palm Beach) set a combined target of replacing 50,000 fossil-fuel-powered fleet vehicles with vehicles that run on alternative fuels by 2025.

In addition to the upgrading of city-owned fleet vehicles, several municipalities require outsourced waste haulers that operate in their area to switch from diesel to CNG vehicles as part of their contractual operating agreement.

Mariordo Mario Roberto Duran Ortiz, CC BY-SA 3.0, via Wikimedia Commons