San Diego MTS Launches CNG Hybrid-Electric Bus

Tag: Carb Generator

The San Diego Metropolitan Transit System (MTS) launched the first commercial bus with a Compressed Natural Gas (CNG) hybrid-electric drive system (CNG Hybrid Drive System).

ISE Corporation (ISE) developed and supplied the CNG Hybrid Drive System, a variant of ISE's successful line of ThunderVolt™ hybrid drive systems.

ISE also integrated the CNG Hybrid Drive System into a standard 40-foot transit bus that was supplied by MTS. Funding for the program was provided by grants from the South Coast Air Quality Management District (SCAQMD), San Diego Air Pollution Control District (APCD), and the California Air Resources Board (CARB). North Island Credit Union participated in the program by providing a unique bus wrap to call attention to the environmentally friendly and technologically advanced bus.

The $1 million CNG hybrid prototype bus will cut significant emissions from the already clean-burning CNG buses in the MTS fleet, providing more power and a quieter ride.

The CNG hybrid bus will travel all over the MTS network, providing commuters the opportunity to experience the new technology. The CNG Hybrid Drive System is expected to provide the following environmental benefits:

-- Significantly greater fuel economy than standard CNG
-- Reduced NOx emission over standard CNG
-- Reduced CO2 emissions
-- Reduced brake wear and brake maintenance
-- Operate quieter than standard CNG buses

The CNG Hybrid Drive System is based on ISE's proven ThunderVolt™ gasoline hybrid drive systems and features a Cummins ISB Gas Plus engine, a Siemens 165kW electrical generator, two Siemens duo inverters, two Siemens 85kW drive motors and Cobasys-developed NiMH batteries. MTS provided a New Flyer bus for the program and New Flyer assisted ISE in the modification of the bus chassis.

San Diego's North Island Credit Union, which is developing a new LEED-certified, environmentally friendly headquarters, was selected by MTS to provide a unique bus wrap for the CNG hybrid bus. The credit union is known for its corporate brand, which includes an iconic illustration of San Diego County's greatest landmarks. Called "Island Paradise," the signature artwork is a perfect fit to highlight the CNG hybrid bus.

The addition of the new CNG hybrid bus to the MTS fleet comes in conjunction with the recently authorized MTS purchase of up to twenty, 35-foot gasoline hybrid buses for delivery this fall, and up to 250, 40-foot conventional CNG powered buses or gasoline hybrid powered buses over the next five years. The new order of buses will be the biggest procurement order in the history of MTS.