NGVs Run on Low-Carbon Renewable Fuel

Renewable natural gas (RNG)—also known as biomethane—is a model alternative fuel. Produced from animal waste, crop waste and sewage, it delivers benefits throughout the fuel cycle. NGVs running on RNG deliver the same low pollutant and greenhouse gas emissions they achieve when running on conventional natural gas.

RNG is the lowest-carbon fuel.

Making RNG captures greenhouse gas (GHG) emissions from agricultural waste and landfills, turning a costly pollution problem into a revenue-generating product that serves California’s climate goals. In fact, RNG has the lowest carbon intensity (CI) values of all fuels rated for the state’s Low Carbon Fuel Standard. According to the California Energy Commission (CEC), CNG from landfill gas and dairy digester biogas reduces life-cycle GHG emissions to 85–90 percent below those of diesel fuel, while biomethane derived from high-solids anaerobic digestion can reduce life-cycle GHG emissions to roughly 115 percent below those of diesel.

The technology is ready to go.

We can put proven technologies to use right now to convert California’s vast waste feedstocks—from dairies, wastewater treatment plants, municipal solid waste plants, agriculture and landfills—to clean-burning RNG.

Waste Management’s fuel production facility at the Altamont Landfill in Livermore already generates as much as 13,000 gallons of RNG per day. The company expects to fuel its entire California NGV fleet with RNG in the near term.

California’s biomethane opportunity is huge.

Waste Management estimates that California’s current recoverable RNG resources could displace more than 900 million gallons of diesel fuel annually. That’s about 25 percent of the diesel fuel used for transportation in California each year.

The CEC invested almost $38.9 million through 2013 in 12 projects to demonstrate and produce RNG in California. These facilities could eventually produce more than 100 million diesel gallon equivalents of RNG, the CEC says.

Distribution and scale are the next challenges.

Clean Energy is already selling RNG under the Redeem brand at the majority of its public CNG and LNG stations in California, and it’s pricing the fuel on par with conventional CNG and LNG.

For RNG to reach widespread availability, however, we need to resolve regulatory and scale issues. RNG can be delivered by truck, but injection into the natural gas pipeline system is essential to realizing the fuel’s full potential. The California Public Utilities Commission is still establishing rules on gas quality and costs that will determine the near-term feasibility of pipeline RNG.

Currently, RNG production costs are relatively high due to the small scale of most non-landfill production facilities and other factors common to emerging technologies. But larger projects, competitive pricing for equipment and contractor services, and reduced costs for interconnecting with utilities should result in lower costs over time.

Photo credit: station courtesy Clean Energy Fuels