The city of San Diego, California is to switch its entire fleet of refuse and recycling collection trucks from diesel fuel to compressed natural gas (CNG) – a cleaner-burning fuel that significantly reduces greenhouse gas emissions and saves taxpayer dollars. Gradually replacing aged vehicles, the fleet will be fully transitioned to CNG by 2022.
“We all know that vehicle emissions are the leading cause of air pollution so the City is leading by example,” Mayor Faulconer said when announcing the transition. “By transitioning to compressed natural gas, we’re making our fleet greener and saving money at the same time. This is a win-win for San Diegans and will help us reach our climate action goals.”
Last month, the City completed the second phase of construction on a new CNG fueling station at the Environmental Services Department’s Collection Services facility. There are now 13 operational fueling posts that can each fill up two CNG vehicles simultaneously. With back-to-base fully automated refueling, the entire fleet will refuel simultaneously using a series of large compressors that take SDG&E pipeline gas from 35 psi (pounds per square inch) to 3,600 psi. Natural gas is stored on the trucks at this “compressed” state and then reduced to 110 psi when it is injected into the engine.
There are two remaining phases to complete the fueling station. When finished, the facility will have the ability to fill up to 152 vehicles simultaneously.
The City currently has 20 CNG vehicles – which reduce smog-contributing pollutants by up to 90% compared to diesel – operating in its fleet that have already begun to use the new station. New CNG-powered vehicles will be purchased as the existing diesel trucks reach the end of their useful lives, ultimately converting the entire fleet by 2022.
Once fully built out, the station will allow the City to replace its existing fleet of 131 diesel-powered collection vehicles with CNG vehicles and reduce the amount of diesel fuel consumed by more than one million gallons annually.
In addition to the environmental benefits, compressed natural gas is significantly cheaper than diesel. Based on current fuel prices, this project will save the City between $1 million and $1.5 million annually in fuel costs once the entire fleet is fully converted. Estimates show that by constructing the facility and compressing the needed fuel for the vehicles, the City of San Diego will be paying less than $1 per diesel gallon equivalent of natural gas compared to the average of $2.39 per diesel gallon.
The total $5.3 million fueling station project is funded partially by a $250,000 grant from the California Energy Commission and $2 million from the City’s Recycling Enterprise Fund. The remaining costs will be covered by the City’s operating budget, or General Fund.
(Source: City of San Diego)