RNG 101

What is renewable natural gas (RNG)?

Biogas is a product of decomposing organic material. Biogas can come from many sources including agricultural waste, food waste, landfills and wastewater treatment plants. Biogas can be burned for electricity or converted into a transportation fuel. 

If used for a transportation fuel, biogas must go through a cleaning process to remove impurities. The end product of which is 98% methane... Renewable Natural Gas (RNG).

How it works (Dairy)

Cow manure enters the Anaerobic Digester and breaks down for 2-4 weeks producing biogas. This raw biogas is cleaned by the Gas Upgrading Skid or "GUS". RNG comes out the other side and is sent down our pipeline where it is compressed at the utility receipt point.

Why does RNG matter?

Unlike other transportation fuels, Lifecycle Analysis gives RNG credit for reducing GHG emissions in two ways:

Cleaner burning. RNG is identical to fossil natural gas. Just like CNG, RNG when used in transportation is cleaner burning than diesel.  

Methane capture. Methane is a greenhouse gas 25 times more potent than CO2. The process of turning wastes that would otherwise be flared or left to naturally decompose into transportation fuel, greatly reduces the amount of harmful methane that is released into the atmosphere. 

For these reasons, RNG is recognized by the California Air Resources Board and the US Environmental Protection Agency as the cleanest transportation fuel pathway on the market... even cleaner than electric!

Monetizing environmental attributes of RNG

State and Federal programs exist in the US to incentivize cleaner transportation fuels. RNG when used as a transportation fuel is eligible to receive credits from the following programs: 

Renewable Fuel Standard (RFS). Administered by the EPA through the Clean Air Act, the RFS mandates that blenders and refiners of petroleum-based fuels procure alternative fuels through its annual Renewable Volume Obligation. Alternative fuel providers receive a Renewable Identification Numbers (RIN) for each gallon of fuel used in transportation. These RINs are then sold to Obligated Parties. RNG qualifies as a cellulosic biofuel and receives a D3 RIN for ethanol gallon equivalent of fuel used in transportation.

Low Carbon Fuel Standard (LCFS). In addition to qualifying for RINs, RNG qualifies for LCFS credits in California and Oregon. The LCFS program uses lifecycle analysis to determine the environmental impact for every fuel pathway issuing a Carbon Intensity (CI) score. Carbon Intensity is measured in grams of CO2 equivalents per megajoule. As part of their Clean Air Plan, California Air Resources Board has mandated an increasingly lower state-wide CI score each year until 2025. For each ton of CO2 equivalents avoided, LCFS creditors, like RNG providers, receive credits. These credits are then sold to deficit-producing entities. Because of the dual pathway to greenhouse gas reduction outlined above, RNG is recognized by ARB as the cleanest fuel pathway in the LCFS program.   

More Information on Environmental Credits

Click here to download California Air Resource Board's LCFS credit calculator.

For a list of Current fuel pathways, click here. 

Questions about LCFS credits or RINs? Want up-to-date LCFS and RIN pricing? Contact us.