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WMATA ALTERNATIVE FUEL/CLEAN FLEET PROGRAMSPRESENTED TO VIRGINIA TRANSIT AGENCIES
JUNE 9, 2009
WMATA OPERATIONAL OVERVIEW
• 5TH largest transit bus fleet in the U.S.
• 1514 buses operating in a 1500 square mile transit zone
• Operating 50M annual miles out of 9 divisions – 3 in Virginia, 3 in D.C. and 3 in Maryland
• WMATA’s fleet is comprised of 461 CNG’s, 87 Hybrids, and 966 Diesels with an average age of 9.3 years.
• WMATA currently has an active procurement for the delivery of 203 hybrid electric buses of which 61 have been delivered (37 in-service). An additional 148 to be purchased, of which 48 will be funded by the ARRA stimulus program.
Low Emission InitiativesWMATA Board of Directors set a goal to be the nationwide leader among transit agencies to reduce emissions
Three pronged approach:1. Clean up existing diesels
2. Buy cleanest technology available (CNG, hybrid or clean diesel)
3. Explore advanced technologies (EV, hybrid, Fuel Cell, after-treatment, etc)
EMISSIONS PROJECTS
• Converted to ultra-low sulphur fuel in October 2001
• 500 + diesel buses retrofitted with particulate filters
• Tests conducted with various after-treatment products
• Various emission and fuel economy tests performed with support from NREL, Department of Energy (DOE) and West Virginia University
• Tests results are available through NREL.
Low Emission Initiatives
Clean up the Diesels
• Introduced cleaner ultra low sulfur diesel (2001)
• Retrofit 524 buses with soot filters
- 90% PM reduction - 95%+ HC, CO reduction
- 10% NOx reduction
• Repower buses
• If nothing else works, retire it!
Low Emission InitiativesBUY CNGs
• Large infrastructure investment - $15M Bladensburg, $12M Four Mile Run
• First order for 164-2001/02 buses, followed by 250-2005, then additional 25-2007, and 22-2008 buses to
coincide with garage retrofits
• Other agencies reported 20-30% lower reliability. WMATA has much better reliability on CNG buses
Cleanest engines available
Loss of electricity can cause operations shut down
Hybrid Maintenance Experience
• Ev 40 Hybrid Drive Unit
• Dual Power Inverter Module (DPIM)
• Energy Storage Unit (Battery)
Major Hybrid System Components
Ev 40 Hybrid Drive Unit
Early inspections of oil pan found debris indicating an Internal problem
• Defective drive units replaced by Allison local service shop
• Analysis by Allison determined source to be a thrust bearing design problem
• Oil sampling program monitoring identified other drive units with problems prior to failure
•Drive units changed-out with improved design drive unit
•All remaining drive units campaigned by Allison
•No failures with the improved design drive unit
Duel Power Inverter Module (DPIM)
• 35 DPIM units replaced to date
• Allison analysis found manufacturing and logic issues with the DPIM control module
• All modules reprogrammed to eliminate false trouble codes
• Recent experience with DPIM has been satisfactory
Energy Storage Unit (Battery)
• Excellent battery history to date
• No maintenance issues
• No battery replacements
• 6 year expected life (per Allison)
Other Maintenance Issues
Transmission Wiring Harness• Source of numerous false trouble codes• Required fleet wide replacement (2 times)• New Flyer component - design issues
Brake Life• 50% improvement of brake lining life • Regenerative braking system
Hybrid Performance Experience
• Total fleet mileage to date: 8,000,000 + miles• Mean Distance Between Failures: 10,499 miles• Fuel Economy: 3.93 MPG
9.5% better than diesel bus fleets
13.2 % better than CNG bus fleets• Fuel economy data from WVU onsite testing• Brake life 50% better than typical low floor bus
Hybrid Fleet MDBF (Miles)
High = 26,878 Low = 5,741 Average = 10,499