A Southern California security company is converting its fleet of Class 5 armored vehicles into plug-in hybrids powered by renewable natural gas with the help of two vehicle modifiers.

Efficient Drivetrains, Inc. (EDI) and North American Repower, which are also based in California, will convert the fleet of six 26,000-pound, medium-duty trucks operated by Sectran Security, the companies announced.

The Sectran Security trucks make frequent stops as part of their highly congested urban routes. At each stop, drivers keep the engines idling for security purposes. They now risk violating California’s strict diesel idling regulations, which prohibit idling for more than five minutes. The converted trucks would eliminate engine idling by operating in all-electric mode during stop-and-go operations on urban routes and in hybrid-mode during highway operations.

The demonstration trucks enable Sectran to reduce annual diesel consumption by more than 31,000 gallons, which will significantly lower fuel costs and nearly eliminate emissions, according to EDI and North American Repower.

The collaboration gained additional support from the California Energy Commission, which approved a $3-million grant from its Energy Research and Development Division. The grant leveraged an additional $3 million in private investment and creating five advanced vehicle jobs.

The demonstration trucks are scheduled for deployment in Southern California in 2016, according to EDI.