Department of Civil, Construction, and Environmental EngineeringNorth Carolina State UniversityRaleigh, NC 27695

Prepared for:

Talking Freight Seminar SeriesFederal Highway Administration

January 17, 2007

BEST PRACTICES FOR GREENHOUSE GAS BEST PRACTICES FOR GREENHOUSE GAS EMISSIONS REDUCTIONS IN FREIGHT EMISSIONS REDUCTIONS IN FREIGHT TRANSPORTATIONTRANSPORTATION

H. Christopher Frey, Ph.D. and Po-Yao Kuo

ObjectivesObjectives

• Identify and characterize potential best practices for reduction of greenhouse gas (GHG) emissions from the freight transportation sector

• Assess and compare these best practices

• Develop a guidebook regarding these best practices

Introduction

• Definition of Key Concepts

• Study Methodology

• List of Best Practices

• Total Modal GHG Emissions Reductions

• Comparisons of Best Practices Assessed Quantitatively

• Inter-modal Substitutions

• Overview of the Guidebook

• Conclusions and Recommendations

0

2

4

6

8

U.S. Total* Freight Sector

GHG Emissions in U.S. Freight Transportation, 2003

*U.S. Total includes Bunker fuel for international aviation and marine

(9%)

Billion Tons CO2 eq.

Distribution of GHG Emissions by Mode within the U.S. Freight Sector, 2003

Air, 5.1%Water,13.4%

Pipeline,16.0%

Truck,59.4%

Rail,6.1%

Total GHG Emissions: 7.20×108 Tons CO2 Equivalent

Rail 6%

Water 13%

Air 5%

Pipeline 16%

Truck 60%

Definitions and Concepts

Best Practices:− Technological or operational strategies− Existing or developing strategies or

technologies− Reduce GHG emissions− Reduce energy use or use of alternative fuels− Reduce refrigerant leakage or increase use of

low Global Warming Potential (GWP) refrigerants

Definitions and Concepts

Subgroup:− A collection of best practices in a mode that

have either common goals or attributesGreenhouse Gas Emissions:− Focus on CO2, CH4, and HFCs − Global Warming Potential (GWP):

GWP = 1 for CO2

GWP = 21 for CH4

GWP = 1,300 for HFC-134a

Developmental Status: New concepts, pilot tests, and commercially available systems

Study Methodology

(1) Identify best practices

(2) Assess maximum reductions in 2025 GHG emissions and energy or refrigerant use

(3) Assess cost savings

(4) Summarize and report assessment results

Assessment of Potential GHG Emissions Reductions for Individual Best Practices

Per-device reductions:• Differences in 2025 per-device emissions with vs.

without the Best Practice (BP)• For alternative fuels, life cycle inventories were

assessed• May apply only to a fraction of devices in a mode

Modal reductions:• Differences in 2025 modal emissions with or without

the BP • Best estimate of market penetration by 2025

Assessment of Potential GHG Emissions Reductions for Multiple Best Practices

Aggregate reductions for a subgroup:- Linear combination of individual best practices- Mutual exclusion

- Some BPs cannot be used simultaneously - Based on BP with the highest reduction potential

- Interaction: - Some BPs can be used together but interact- Quantification of interaction is unknown or not

reported- Used a linear combination as an estimate

Qualitative and Quantitative Assessment of Best Practices

• Quantitative estimates of the reductions in GHG emissions, energy use and refrigerant use are made for all best practices

• Quantitative Assessment of Costs of Best Practices:

- Where sufficient cost data are available

- Summarized in standardized reporting tables

• Qualitative Assessment of Best Practices:

- Lack of quantitative cost data

- Summarized in simplified summary tables

Quantitative Assessment of Best Practices (Example: Auxiliary Power Units)

A truck with sleeper cab is estimated to consume up to 0.85 gallons of diesel per hour while idling

Source: Volvo Trucks North America, www.volvo.com/trucks/na/en-us/

Auxiliary power units (APUs) are estimated to consume 0.2-0.4 gallons of diesel per hour

Quantitative Assessment of Best Practices (Example: Auxiliary Power Units)

Practice goals, 2025: - Trucks with sleeper cabs

- Reduce CO2 by 15 million tons per year - Reduce energy use by 185 Tera BTU per

yearPractice summary: Auxiliary power units (APU)

- Small diesel engine-generator- Used instead of base engine for idling- Supply power for electrical air conditioning,

heating, and auxiliary loads

Quantitative Assessment of Best Practices (Example: Auxiliary Power Units)

Variable Unit Value

Annual ton-miles for the mode 109 ton-miles/year 2,098

Annual ton-miles to which a practice is applicable

109 ton-miles/year 453

Annual GHG emissions reduction 106 ton CO2 eq./year 15.0

Annual energy use reduction 1012 BTU/year 185.0

Unit GHG emissions reduction 10-3 lb CO2 eq./ton-mile 66

Unit energy use reduction BTU/ton-mile 409

Standardized Reporting Table for Expected Reductions, 2025

Quantitative Assessment of Best Practices (Example: Auxiliary Power Units)

Variable Unit Value

Capital cost 106 USD ($) 9,370

Annual O & M cost $ 106 /year 520

Annualized cost $ 106 /year 2,990

Annual energy cost saving $ 106 /year 3,430

Net savings $ 106 /year 440

Net savings per unit of GHG emissions reductions*

$/ton CO2 eq. 29

Net savings per unit of energy use reduction*

$/106 BTU 2.3

Simple payback period years 3.2*Positive values denote cost savings

Standardized Reporting Table for Expected Practice Costs and Cost Savings, 2025

Summary of Best Practices for Freight Transportation

A total of 59 potential best practices have been identified

ModeNumber of Potential Best

Practices

Truck 33

Rail 6

Air 10

Water 5

Pipeline 5

List of 33 Best Practices for the Truck Mode

Subgroup Names of Best Practices Note

Anti-idlingTruck Stop Electrification (Off-board, on-board);* Auxiliary Power Units;* Direct-fired Heaters (with or without Thermal Storage Units

E*

Air Conditioning System

Improvement

Enhanced Air Conditioning System (to reduce Direct Emissions# or Indirect Emissions); Alternative Refrigerants: CO2;*, # HFC-152a;*, # HC*, #

E*I#

Aerodynamic Drag Reduction

Vehicle Profile Improvement (Tractor; Truck Side and Underside;# Trailer or Van); Pneumatic Aerodynamic Drag Reduction;*, # Planar Boat Tail Plates on a Tractor-trailer; Vehicle Load Profile Improvement*

E*I#

Tire Rolling Resistance

Improvement

Automatic Tire Inflation Systems; Wide-base Tires;* Low-Rolling-Resistance Tires;* Pneumatic Blowing to Reducing Rolling Resistance

E*

E *= mutually exclusive within a subgroup; I# = interaction within a subgroup.

List of 33 Best Practices for the Truck Mode (Continued)

Subgroup Names of Best Practices Note

Hybrid Propulsion Hybrid Trucks

Weight Reduction Lightweight Materials

Transmission Improvement

Advanced Transmission; # Low-viscosity Transmission Lubricants#

I#

Diesel Engine Improvement

Low-viscosity Engine Lubricants; Increased Peak Cylinder Pressures; Improved Fuel Injectors; # Turbocharged, Direct Injection to Improved Thermal Management; # Thermoelectric Technology to Recovery Waste Heat

I#

Accessory Load Reduction

Electric Auxiliaries;*, # Fuel-cell-operated Auxiliaries*, # E*I#

Driver Operation Improvement

Truck Driver Training Program

Alternative Fuel B20 Biodiesel Fuel for Trucks

E* = mutually exclusive within a subgroup; I# = interaction within a subgroup.

List of 6 Best Practices for the Rail Mode

Subgroup Names of Best Practices Note

Anti-idlingCombined Diesel Powered Heating System and Auto Engine Start/stop System;* Battery-diesel Hybrid Switching Locomotive;* Plug-in Units*

E*

Weight Reduction Lightweight Materials

Rolling Resistance Improvement

Lubrication Improvement

Alternative Fuel B20 Biodiesel Fuel for Locomotives

E* = mutually exclusive within a subgroup; I# = interaction within a subgroup.

List of 10 Best Practices for the Air Mode

Subgroup Names of Best Practices Note

Aerodynamic Drag Reduction

Surface Grooves; Hybrid Laminar Flow Technology; Blended Winglet;* Spiroid Tip*

E*

Air Traffic Management Improvement

Air Traffic Management Improvement

Weight reductionAirframe Weight Reduction; Non-essential Weight Reduction

Ground Support Equipment Improvement

Ground-based Equipment as an Alternative to Auxiliary Power Units; Electric or Hybrid Heavy Duty Delivery Trucks

Engine Improvement

Improved Engine Combustion Efficiency

E* = mutually exclusive within a subgroup; I# = interaction within a subgroup.

List of 5 Best Practices for the Water Mode

Subgroup Names of Best Practices Note

Propeller System Improvement

Off-center Propeller;* Propeller Boss Cap with Fins;* Auxiliary Free-rotating Propulsion Device behind the Main Propeller*

E*

Anti-idling Shoreside Power for Marine Vessels at Ports

Alternative Fuel B20 Biodiesel Fuel for Ships

E* = mutually exclusive within a subgroup; I# = interaction within a subgroup.

List of 5 Best Practices for the Pipeline Mode

Subgroup Names of Best Practices Note

Process Control Device Improvement

Convert Natural Gas Pneumatic Controls to Instrument Air; Replace High-bleed Natural Gas Pneumatic Devices with Low-bleed Pneumatic Devices

Connecting Method “Hot Tap” Method

Maintenance Transfer Compression; Inline Inspection

Total 2025 Modal GHG Emissions Reductions Compared to 2025 Without Best Practices

GHG EmissionsReductions (%)

0

10

20

30

40

50

60

70

Truck Rail Air Water Pipeline

New Concepts

Pilot Tests

CommerciallyAvailable Systems

Total 2025 Modal GHG Emissions ReductionsCompared to 2025 Without Best Practices

Reductions in Total Modal GHG Emissions (Million Tons CO2 eq.)

0

50

100

150

200

250

300

350

400

450

Truck Rail Air Water Pipeline

New Concepts

Pilot Tests

Commercially AvailableSystems

Changes in GHG Emissions from 2003 to 2025 with Best Practices

Total Modal GHG Emissions (Million Tons CO2 eq.)

0

200

400

600

800

Truck Rail Air Water Pipeline Total

2003 Modal GHG Emissions

2025 Modal GHG Emissions withBest Practices

Changes in GHG Emissions from 2003 to 2025 with Best Practices

Percentage Change (%)

-40%

-20%

0%

20%

40%

Truck Rail Air Water Pipeline Total

The Percentage change in GHGemissions from 2003 to 2025

Comparisons of Best Practices Assessed Quantitatively

• To date, sufficient information has been obtained to assess 13 practices quantitatively.

Mode Name of Best Practices

Truck

1. Off-board Truck Stop Electrification

2. Auxiliary Power Units

3. Direct-fired Heaters

4. Hybrid Trucks

5. B20 Biodiesel

Rail

6. Combined Diesel Powered Heating and Start/stop System

7. Battery-diesel Hybrid Switching Locomotive

8. Plug-in Units

9. B20 Biodiesel

Comparisons of Best Practices Assessed Quantitatively (Continued)

Mode Names of Best Practices

Water 10. B20 Biodiesel

Pipeline

11. Natural Gas-powered Pipeline Process Control Device: replaced by compressed air-powered

12. Natural Gas-powered Pipeline Process Control Device: replaced by low-bleed pneumatic devices;

13. “Hot Tap” Method

GHG Emissions Reductions (Million Tons CO2 eq. / Year)

Truck

Comparison of Best Practices Assessed Quantitatively (Continue)

Rail Water Pipeline

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10

15

20

25

30

35

1 2 3 4 5 6 7 8 9 10 11 12 13

Auxiliary

Power

Units

Hybrid

Trucks

B20 Biodiesel

Net Cost Savings (Million $ / Year)

-4000

-3000

-2000

-1000

0

1000

2000

3000

1 2 3 4 5 6 7 8 9 10 11 12 13Truck

Comparisons of Best Practices Assessed Quantitatively (Continued)

Rail Water Pipeline

Auxiliary

Power

Units

Hybrid

Trucks

B20

Bio-

diesel

Inter-Modal Comparison of Average ModalGHG Emission Rates

GHG Emissions per Unit of Freight Transport (lb CO2 eq. / ton-mile)

0.0

0.5

1.0

1.5

2.0

2.5

Truck Rail Air Water Pipeline

Overview of the Organization and Content of The Guidebook

Definitions and ConceptsChapter 2

MethodologyChapter 3

Fuel PropertiesAppendix F

Background and Methodology

Assessments of Individual and Subgroups of Best Practices by Mode

Mode Summary Material Supporting DetailsTruck Chapter 4 Appendix ARail Chapter 5 Appendix BAir Chapter 6 Appendix CWater Chapter 7 Appendix DPipeline Chapter 8 Appendix E

Summaries of and Comparisons

Between ModesChapter 9

Conclusions and Recommendations

Chapter 10

Conclusions

• Aggressive implementation of best practices may lead to a net decrease in total GHG emissions in freight transportation

• Even larger percentage reductions are possible if Inter-modal shifts (e.g., substitute rail for truck) are encourage

Conclusions

• There is limited quantitative data upon which to base assessments of best practices

• For 13 best practices for which adequate data are available:

- The normalized cost savings per unit of GHG

emissions reduction was highly variable

- The variability mostly depends on the magnitudes

of their energy cost savings.

Conclusions

• Some best practices (e.g., biodiesel for trucks) offer potential for large magnitudes in GHG emissions reductions, but may not be as cost-effective

– From a national policy perspective, governments should promote research, development, and demonstration (RD&D) to foster best practices that lead to large absolute reductions in GHG emissions

• Some best practices may lead to “no regrets”– e.g., net cost savings to an operator– Additional benefits of GHG emissions or energy use

reduction

Recommendations

• Update information as new information becomes available

• Evaluate key assumptions (e.g., market penetration rates) that influence the selection of best practices via sensitivity analysis

• Develop tools (e.g., a decision tree, a decision support framework) to support decision making regarding best practices

Acknowledgement/Disclaimer

• This work is supported by the U.S. Department of Transportation via Center for Transportation and the Environment.

• The authors are responsible for the facts and accuracy of the data presented herein.

• The contents do not necessarily reflect the official views or policies of either the U.S. Department of Transportation or the Center for Transportation and the Environment at the time of publication.

• This report does not constitute a standard, specification, or regulation.