NYCT OPERATING EXPERIENCE WITH HYBRID TRANSIT BUSES Gary LaBouff Director, Research & Development May, 2006
Overview of NYCT Bus Operations
NYCT Bus Operations (2005) n Annual Bus Customers740,586,160 n Average Weekday Ridership2,361,299 n Total Buses in Fleet 4,512 n # of Bus Routes243 n # of Bus Stops12,693 n # Of Total Employees14,061 n Annual Mileage 119,495,228 n Gallons of Fuel Consumed è Diesel 41,116,861 è CNG 7,156,336
NYCT Bus Fleet
1. Reduce Bus Fleet Emissions - Achieve levels below current U.S. mandates 2. Improve Service - Improve equipment reliability - Achieve quieter operation 3. Reduce the Cost of Operations - Improve fuel economy - Reduce maintenance costs - Avoid infrastructure costs NYCT Goals
The Clean Fuel Solution - Hybrid Electric n Hybrid Electric buses combine a diesel engine and electric drive components n Improved performance è Significant emissions reduction è Increased fuel economy è Smooth and quiet operation n Avoids the infrastructure costs of CNG - no special fuel handling is required
BAE/Orion VII Hybrid System Lead Acid Battery Packs Diesel Engine Generator Electric Traction Motor Power Electronics Lead-Acid Batteries Diesel Engine Generator Power Electronics (PCS) Traction Motor
NYCT Hybrid Bus Programs
NYCT Hybrid Bus Programs - Overview n Successful prototype in 1996 (Orion/GE) n Pilot fleet of 10 Orion VI/BAE hybrid buses began revenue service in 1998 n 125 Production Orion VII/BAE Gen. I hybrid buses ordered - pilot bus in 2003, production deliveries in 2004 n 200 Production Orion VII/BAE Gen. II hybrid buses ordered - pilot bus in 2004, production deliveries in 2005 n 500 Additional Orion VII/BAE Gen. II+ ordered, (216 NYCT,284 MTA BUS) - Delivery by 6/07.
Revenue Service Experience - Orion VI n Hybrid buses in service since Sept n Met standard performance specs n Approx. 700,000 revenue miles n Drivers and customers like the buses n Brake life approximately doubled n Very positive - for a brand new technology, have exceeded expectations
Orion VII/BAE Hybrid Buses - Gen. I n First of 125 into service in February, 2004 n As of 1 April 2006: è 125 Buses in service è Approx. 5.5 million revenue service miles to date è Two depots; Bronx & Queens n Used interchangeably with standard buses n Fuel economy and emissions better than Orion VI hybrid buses
Orion VII/BAE Hybrid Buses - Gen. I Design Improvements over Orion VI n Active Control of Generator è Variable engine speed n Improved Traction Motor è Planetary gear reduction è Redesigned bearing system n Redesigned Packaging n Particulate Filter with Active Control n Improved Diagnostic System n Improved Re-gen Control for Smoother Braking
Orion VII/BAE Hybrid Buses - Gen. II n First of 200 into service in December, 2004 n As of 1 April 2006: è 200 Buses in service è Over 3.5 million revenue service miles è Two depots, Brooklyn and Manhattan n Smoother and quieter than Generation I
Orion VII/BAE Hybrid Buses - Gen. II Design Improvements over Orion VII Gen. I n New Generator - Flywheel Mounted - (currently being redesigned) n New Design Coolant/Lube Pumps n Oil Cooled Propulsion Control System n Improved Accessibility n Software Upgrade n Updated engine - EGR with common rail fuel system
Orion VII Hybrid Bus Revenue Miles
NYCT Fleets Composite Fuel Economy
Emissions Comparison
EPA Regulated Emission Levels for Heavy Duty On-Highway Engines - PM & NOx
Hybrid Bus Reliability (MDBF) 01 6 Month Rolling Average 6 Month Rolling Average
Orion VI Lead Acid Battery Life n For the 36 months of testing ending in February of 2004: è 17,000,000 Battery-miles, 5% replaced è Replaced batteries did not appear to be end-of- life failures è Two buses in service for 40+months with no failures n Life goal of 3 years appears to be potentially achievable but not realized yet n Changes to software in Orion VII should reduce battery replacements
Hybrid Electric Costs
Life Cycle Costs - HEV vs Standard n Current differential in acquisition costs make justification of HEVs, based on costs alone, difficult at todays fuel prices è Current hybrid differential is $ K per bus è Series HEVs in NYCT high density duty cycle can achieve over 30% improvement in fuel economy over standard diesel/transmission systems è This can result in a savings of approx. 50,000 gallons of fuel over a 12 year life of the bus. è If todays fuel prices double, the savings can negate the initial cost differential.
Fuel Costs - Series HEV vs Std. Propulsion
Life Cycle Costs - HEV vs Standard n Other factors contribute to HEV cost savings è Brake life è Diesel Particulate Filter maintenance u HEV system can control regeneration process and reduce filter problems è Transmission overhaul n Other non-cost factors favor hybrids è Lower noise signature è More flexibility in vehicle energy management è Emissions
Lessons Learned from Hybrid Buses
Lessons Learned - Operational n Bus operators and passengers like hybrids è Quiet, smooth operation è excellent acceleration/smooth braking è feels like a standard bus è little or no operator training required n Able to be used on all NYCT routes n Bus does not roll back on hills
Lessons Learned - Maintenance n More advanced troubleshooting procedures and tools required è More components and subsystems/interfaces è More wiring and connectors n Long term, reliable, and cost effective energy storage solution still not clear è Lead acid batteries have limited life and can be reliability drivers due to the number required è NiMH still expensive and life unproven è Ultra capacitors, Lithium Ion batteries still in development.
NYCT Hybrid Bus - Future Plans n Evaluate alternative energy storage technologies n Evaluate alternative hybrid system technologies n Continue to develop integrated diagnostic/prognostic systems n Pursue goal of 10,000 hour MDBF for hybrid buses n Move toward all electric accessories
Hybrid Buses - Future Challenges n Component Optimization - HEV allows for the use of other electrically driven system components. n Electric components have inherent advantages: è Remote mounting - better packaging è More efficient è High reliability index è Reduced noise signature
Hybrid Buses - Future Challenges n Opportunities for Electrically Driven Accessories: è Short term u Compressors, air and HVAC u Steering u Cooling system è Long Term u Wheel motors u ZPE operation u Fuel cell integration
Additional Information n Speaker Contact: Gary LaBouff, Director - Research & Development MTA New York City Transit (718) ; n Hybrid/CNG/Diesel Emissions Report n NREL Reports: reports 6369 and 6383