This report is part of a series of evaluations from the U.S. Department of Energy (DOE). DOE, through the National Renewable Energy Laboratory (NREL), has been tracking and evaluating new propulsion systems in transit buses and trucks for more than 10 years using an established and documented evaluation protocol. DOE/NREL evaluated the original 10 prototype diesel hybrid buses from Orion and BAE Systems (model Orion VI buses) operated at New York City Transit (NYCT). That evaluation was reported in July 2002 and provided results from the prototype buses from 1998 through 2001.
These DOE/NREL vehicle evaluations are a part of the Advanced Vehicle Testing Activity (AVTA), which supports DOE’s FreedomCAR & Vehicle Technologies Program. The role of AVTA is to bridge the gap between research and development and commercial availability of advanced vehicle technologies that reduce U.S. petroleum use while improving air quality. The main objective of AVTA projects is to provide comprehensive, unbiased evaluations of advanced technologies. Data collected and analyzed include the operation, maintenance, performance, safety, cost, and emissions characteristics of advanced technology fleets and comparable conventional technology fleets operating at the same site. By comparing available advanced and conventional technology vehicles, AVTA evaluations help fleet owners and operators make informed purchasing decisions.
This report focuses on compressed natural gas (CNG) and diesel hybrid electric bus propulsion systems in NYCT’s transit buses. Both of these propulsion systems are alternatives to standard diesel buses and allow for reductions in petroleum use and emissions (usually focused on reductions of particulate matter and oxides of nitrogen). CNG propulsion is an alternative to diesel fuel use, and diesel hybrid propulsion allows for increased fuel economy, which, in turn, is a reduction in petroleum use.
This report describes the evaluation results for Orion VII low floor buses at NYCT with CNG propulsion (Detroit Diesel Corporation Series 50G CNG) and hybrid propulsion (BAE Systems HybriDrive® propulsion system). These interim results represent eight out of a planned 12-month evaluation of these two groups of buses. An additional evaluation of NYCT’s order of 200 Orion and BAE Systems hybrid buses will be reported separately. The evaluation period presented in this report covers October 2004 through May 2005; the final evaluation report will include data through September 2005. This interim report was created to expedite the release of information collected on these technologies.
The CNG buses evaluated were part of an order of 260 Orion VII CNG buses that started into service in September 2003 at Jackie Gleason Depot and later at West Farms Depot. NYCT expected the buses to seamlessly replace older diesel buses after CNG fueling infrastructure was added and training was completed at the newly opened West Farms Depot.