The City of Long Beach (Calif.) has transitioned its heavier vehicles to run on renewable liquid natural gas (RNG) and is discontinuing the use of fossil liquid natural gas (LNG) to reduce emissions and fuel costs, according to the agency.

The move will affect 85 LNG-powered vehicles including 55 refuse trucks, 78 heavy-duty Class 8 trucks, 16 street sweepers, three dump trucks, two tractor trucks, and two rear loaders. The city's fleet operations division didn't need to make any modifications to the vehicles, said Oliver Cruz, fuel operations program officer.

The city switched over the vehicles in October, and will rely on two existing 16,300-gallon RNG storage tanks located on city property.

"We do not expect any changes for the amounts of RNG we store on-site," Cruz said.

The switch is expected to net the city cost savings of about $0.327 per gallon. Based on the past year of usage, the savings should be about $27,000 per year, Cruz said. The city used more than 823,000 gallons of LNG over the past 12 months.

"With California’s Low Carbon Fuel Standard (LCFS) credits, producers of renewable fuels are able to provide competitive pricing," Cruz said. "RNG is actually less expensive than fossil LNG for the City of Long Beach."

Renewable natural gas (also known as biomethane) significantly reduces greenhouse gas emissions. It's sourced from methane from landfills and animal waste that's released into the atmosphere and used for conversion into RNG.

This methane is combusted as renewable gas resulting in greenhouse gas releases that are approximately 21 times less potent than methane released directly into the atmosphere. The use of RNG represents the recycling of carbon that is already circulating in the environment, whereas burning fossil LNG represents the release of new carbon emissions that were previously sequestered in the earth, Cruz said.

"The shift to RNG was an easy choice for the city because of the environmental benefits," Cruz said. "According to the California Air Resources Board, RNG's carbon emissions when measured over the lifecycle of the fuel's production, transport and use, is the lowest of any vehicle fuel that is commercially available."