Table 5 Summary of Results from NREL Hybrid and Natural Gas Bus Evaluations

Table 5 Summary of Results from NREL Hybrid and Natural Gas Bus Evaluations

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  Unit DART
6/98 - 1/00
40-ft LNG
40-ft Diesel
WMATA
9/01 - 9/04
40-ft CNG
40-ft Diesel
KC METRO
4/05 - 3/06
60-ft Diesel Hybrid
60-ft Diesel
NYCT
10/04 - 8/05
40-ft Diesel Hybrid
40-ft CNG
Capital ($ mill)          
Diesel Fuel Station total not reported not reported not reported not reported
NG Fuel Station total $ 7.50 $ 4.00 NA $ 7.40
Hybrid Depot Modifications total NA NA None $0.14/depot - 2 battery conditioners
NG Depot Modifications total incl in NG fuel station $ 11.60 NA not reported
Hybrid Bus Purchase ea NA NA $ 0.645 not reported
NG Bus Purchase ea not reported $ 0.34 NA not reported
Fuel Economy          
Duty Cycle MPH 13.7 - 14.4 11.6 11.6 - 12.4 6.2 - 6.5
Hybrid Fuel Economy MPG NA NA 3.17 3.2
NG Fuel Economy MPDEG 2.70 2.32 - 2.39 NA 1.7
Diesel Fuel Economy MPG 3.80 2.84 2.50 2.30 - 2.40
Fuel Cost          
NG Cost $/DEG $ 0.82 $ 1.50 NA $ 1.74
Diesel Cost $/gal $ 0.90 $ 1.33 $ 1.98 $ 1.78

  Unit DART
6/98 - 1/00
40-ft LNG
40-ft Diesel
WMATA
9/01 - 9/04
40-ft CNG
40-ft Diesel
KC METRO
4/05 - 3/06
60-ft Diesel Hybrid
60-ft Diesel
NYCT
10/04 - 8/05
40-ft Diesel Hybrid
40-ft CNG
Maintenance Cost   LNG Diesel CNG Diesel Hybrid Diesel Hybrid CNG
PMI $/mi $ 0.07 $ 0.07 $0.12-$0.14 $ 0.17 $ 0.05 $ 0.05 $ 0.17 $ 0.12
Powerplant $/mi $ 0.08 $ 0.06 $0.11-$0.12 $ 0.11 $ 0.11 $ 0.12 $ 0.17 $ 0.25
Drive System $/mi $ 0.02 $ 0.01 $0.01-$0.03 $ 0.04 $ 0.01 $ - $ 0.18 $ 0.04
Fuel System $/mi $ 0.01 $ 0.01 $0.01-$0.02 $ 0.01 $ 0.01 $ - $ 0.02 $ 0.06
TOTAL PROPULSION $/mi $ 0.11 $ 0.08 $0.13-$0.17 $ 0.16 $ 0.13 $ 0.12 $ 0.37 $ 0.35
NON-PROPULSION $/mi $ 0.29 $ 0.45 $0.39-$0.41 $ 0.43 $ 0.31 $ 0.34 $ 0.86 $ 0.94
TOTAL $/mi $ 0.40 $ 0.53 $0.52-$0.58 $ 0.59 $ 0.44 $ 0.46 $ 1.23 $ 1.29

NOTES

DART: Capital costs are for two LNG fuel stations and modifications at two depots
Warranty costs not included

WMATA: CNG cost includes $0.14/DEG for compression (electricity) and $0.17/DEG for fuel station O&M ($360,000/yr)
Warranty costs not included

KC METRO: All buses 60' New Flyer D60LF. Hybrids included Allison EP50 system
Warranty costs of $0.17 - $0.20/mi for both diesel and hybrid buses
Diesel and hybrid buses operated from different depots. A direct route comparison showed a 21-22% increase in FE for hybrids

NYCT: CNG fuel station is 6,600 scfm. Cost includes $2 mill for NG line extension to depot
CNG cost includes $0.35/DEG for compression and fuel station maintenance
All buses were 40' Orion VII. Hybrids included BAE HybriDrive system
Warranty costs not included

For all agencies maintenance costs calculated using $50/hr mechanic labor rate

SOURCES

DART: NREL, Dart's LNG Bus Fleet Final Results, October 2000

WMATA: NREL/TP-540-37626 April 2006

KC Metro: NREL/TP-540-40585 December 2006

NYCT: NREL/TP-540-40125 November 2006