Using Argonne’s Modeling Software to Estimate Benefits of Alternative Fuel Vehicles

Andy BurnhamClean Cities University Workforce Development Program Webinar August 8, 2012

Outline

Life-Cycle Analysis and GREET Model Introduction

Example of Current Life-Cycle Analysis Research– Shale gas greenhouse gas emissions

GREET Fleet Footprint Calculator Introduction

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Life-Cycle Analysis and GREET Model Introduction

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From the Department of Energy’s Perspective Transportation Sector: Dual Challenges, Dual Approaches

Challenges– Oil use (energy security)– Greenhouse gas emissions (climate change)

Approaches– Vehicle efficiency– New transportation fuels

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Sources: Transportation Energy Data Book: Edition 27 and projections from the Early Release Annual Energy Outlook 2009.

U.S. Petroleum Production and Consumption 1970-2030

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1970

1975

1980

1985

1990

1995

2000

2005

2010

2015

2020

2025

2030

Mil

lio

n b

arre

ls p

er d

ay

MarineRail

Cars

Air

Light Trucks

Heavy Trucks

U.S. ProductionOff-Road

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Highway Vehicles Contribute Significantly to U.S. Greenhouse Gas Emissions

2009 U.S. GHG emissions from fossil fuels = 5.2 Gt of CO2e (EPA 2011)6

Transportation33%

Industrial26%

Residential22%

Commercial19%

2009 Fossil Fuel GHG Emissions by End-Use Sector

Light Duty65%

Heavy Duty Trucks & Buses

21%

Air8%

Water2%

Rail2%

Pipelines2%Other

0%

2009 Fossil Fuel GHG Emissions by Transportation Mode

Life-Cycle Analysis for Vehicle/Fuel Systems Has Evolved in the Past 30 Years

Pursuing reductions in transportation petroleum use and GHG emissions requires for well-to-wheels (WTW) analyses

Pioneering WTW analyses began in 1980s– Early studies were motivated primarily by battery-powered EVs

Recent studies are motivated primarily by introduction of– New fuels such as cellulosic ethanol

– New vehicle technologies such as plug-in hybrids

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Life-Cycle Analysis of Vehicle and Fuel Systems in the GREET Model

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The GREET Model Estimates Energy Use, GHGs, and Criteria Pollutants

Separates energy use into:– Total energy

• Fossil energy• Renewable energy

Includes emissions of greenhouse gases – CO2, CH4, and N2O

Estimates emissions of six criteria air pollutants– VOC, CO, NOx, SOx, PM10, and PM2.5

The GREET model and its documents are available at Argonne’s website at http://greet.es.anl.gov/

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As an example, greenhouse gases are illustrated here

Taking the Results from GREET Can Provide Us with a Life-Cycle Comparison

Example of Current Life-Cycle Analysis Research

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Shale Gas Has Been Described as a Game Changing Resource, Which Could Permit Expanded NG Usage

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Source: EIA Annual Energy Outlook 2011

However Boom in Shale Gas Production Has Brought Attention to its Potential Environmental Impacts

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Large-scale production made possible due to recent advancements

– Horizontal drilling– Hydraulic fracturing

Environmental issues are beginning to be examined

– Water quality– Water quantity– Local air pollution– Greenhouse gas emissions

Source: EPA

EPA Has Recently Made Significant Changes to the Estimate of CH4 Emissions from the Natural Gas System

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Source: EPA – U.S. GHG Inventory Archive

Major changes include adding emissions from shale gas operations

Developed GREET shale gas pathway– Updated CH4 leakage estimates for conventional NG, petroleum, and coal

pathways

Focus of analysis was to estimate uncertainties and identify data gaps to provide insight to NG industry and government

Scope of Argonne’s Natural Gas Life-Cycle Analysis

Well InfrastructureNatural Gas Recovery

ProcessingTransmission and

DistributionEnd Use

(Photographs by J. Veil)

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Key Issues Affecting Natural Gas Life-Cycle Results

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Estimated Ultimate Recovery (EUR)

Shale Gas Well Completion Emissions

Conventional Gas Liquid Unloading Emissions

Global Warming Potential

End Use Efficiency

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Periodic Well Emissions Must be Allocated Over Lifetime NG Production

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Several key activities are estimated on a per-well basis– Lower the EUR, larger the impact

Shale gas EURs are highly uncertain as industry is in its infancy– Wide range for several plays

Conventional NG productivity is declining– Lower EUR than key shale plays

Low EUR Estimate (Bcf)

High EUR Estimate (Bcf)

Barnett 1.4 3.0Marcellus 1.4 5.2Fayetteville 1.7 2.6Haynesville 3.5 6.5Shale Per-Well Weighted Avg. 1.6 5.3

Conventional Avg. 0.8 1.217

Shale Gas Completions CH4 Emissions Could Be Large, But Industry Data Says Much is Recovered After hydraulic fracturing, a large volume of frac fluid & produced water

return to the surface– Flowback water contains NG, which can be vented, flared, or captured

EPA estimates “uncontrolled” CH4 emissions– Data used by EPA to calculate emissions have significant questions

EPA then calculates amount of NG flared and captured by industry practices using NESHAP regulations and NG STAR reporting

– Emissions were reduced by ~40% from 2005-2009– Lack of transparency as data is highly aggregated

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EPA’s Estimates Liquid Unloadings Account for Half of Uncontrolled CH4 Emissions From NG Production Accumulation of fluids in wet NG wells can eventually stop production

– Assumed to only occur in conventional wells (shale typically dry)– Removing liquids can be accomplished by several practices/technologies

Similar to issues with completion emissions, uncertainty arises from– Suitability of NG STAR data to calculate uncontrolled emissions– Lack of transparency regarding NG STAR reductions

Our examination found that liquid unloading emissions are potentially more significant than those from shale gas well completions

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Global Warming Potential is a Simple Measure to Compare Radiative Effects of Different Gases Need to choose a time-horizon when comparing emission impacts of

different fuels– Especially important when comparing contributions of short-lived gases

• CH4 has an atmospheric lifetime of ~12 years

IPCC recommends using a 100-year time-horizon when evaluating climate change mitigation policies

Other researchers have suggested a 20-year time-horizon should be examined

– Effects of CH4 emissions are amplified

We use the 100-year time-horizon in our analyses– Also present 20-year for comparison to other studies

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End-use Efficiency is a Key Factor for LCA Results

Compared to gasoline cars, NG cars have slightly lower fuel economy– Base case = 5% reduction

• Weight penalty of CNG storage tanks• Power loss due to oxygen displacement

– Use of direct injection and turbocharging can improve fuel economy and power

Compared to diesel transit buses, NG buses have moderately lower fuel economy

– Base case = 15% reduction• Spark-ignited engines have low efficiency at low speeds

– However NG spark-ignited engines have closed the gap on compression-ignition engines

• Primarily due to emission control strategies implemented for diesels to meet 2010 regulations

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CNGVs Using Fossil NG May Provide Small GHG Benefit, Improving Vehicle Efficiency Would Help

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Interesting result - base-case shale gas emissions are lower than conventional NG– Values overlap so can’t say one is actually better than the other

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Shale Gas and Conventional NG Summary

Estimates of CH4 leakage from NG have increased significantly

Shale gas completion emissions could be large in theory– However, industry reports that a significant amount is captured– Data is extremely limited and there is a lack of transparency

• Several efforts underway to get better data

Conventional NG liquid unloadings are potentially a larger source than shale gas completions

– Causes the greatest amount of uncertainty in our study

Shale and conventional NG may provide small GHG benefits for passenger cars and transit buses

– NGV efficiency is a key factor for improvement

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GREET Fleet Footprint Calculator Introduction

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GREET Fleet Allows Users to Estimate Petroleum and Carbon Footprints

Starting in 1998, US DOE and EPA co-sponsored Argonne to develop a tool, AirCRED, to assist Clean Cities coalitions to estimate ozone precursor and carbon monoxide emission credits from AFVs

– For use in State Implementation Plans (SIPs)

Now with the interest in measuring petroleum use and carbon/greenhouse gas emissions, Clean Cities sponsored Argonne to develop the GREET Fleet Footprint Calculator

– Developed in Microsoft Excel and uses simple spreadsheet inputs– Results are on WTW basis

This tool was designed for:– On-road-medium and heavy-duty vehicles– Off-road equipment

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GREET Fleet is Available for Download

Contains 12 fuel/vehicle types– Conventional: gasoline and diesel– Hybrid: diesel HEV– Alt. fuel: biodiesel (B20 and B100), ethanol (E85), CNG, LNG, LPG, electricity, gaseous

and liquid hydrogen• Additional simulation options include:

– Corn vs. cellulosic ethanol– North American NG vs. Non North American NG vs. Landfill Gas– Electricity mix (% coming from coal, natural gas, nuclear, etc.)– Several hydrogen production pathways

GREET Fleet is based off the current public version of GREET

You can find GREET Fleet and its user manual at:http://greet.es.anl.gov/fleet_footprint_calculator

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GREET Fleet Tutorial

Comparing On-Road Vehicle Technologies for Potential Acquisitions

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GREET Fleet Tutorial – Comparing On-Road Vehicle Technologies for Potential Acquisitions

First step: choose how to calculate footprint on ‘On-road fleet sheet’– Choose “Option 1” to calculate using fleet size, VMT & fuel economy

1. Method to Calculate On-Road Fleet's Petroleum Energy Use and GHG Footprint1 1 - Fleet size, vehicle miles traveled, and fuel economy

2 - Fuel use (skip to question 5)

Second step: enter the amount of vehicles– In this demo we will compare diesel transit buses to: diesel hybrid, B20, &

CNG

2. The Number of Each Type of Vehicle in On-Road Fleet

Gasoline DieselDiesel

HEVBiodiesel

(B20)Biodiesel

(B100)Ethanol

(E85)

Compressed Natural Gas

(CNG)School Bus 0 0 0 0 0 0 0Transit Bus 0 20 20 20 0 0 20Shuttle/Paratransit Bus 0 0 0 0 0 0 0Waste Hauler 0 0 0 0 0 0 0Street Sweeper 0 0 0 0 0 0 0Delivery Step Van 0 0 0 0 0 0 0Transport/Freight Truck 0 0 0 0 0 0 0Medium/Heavy Duty Pickup Truck 0 0 0 0 0 0 0Maintenance Utility Vehicle 0 0 0 0 0 0 0Other 0 0 0 0 0 0 0

Note: Several fuels to the right of CNG are not shown for clarity in this presentation 28

GREET Fleet Tutorial – Comparing On-Road Vehicle Technologies for Potential Acquisitions

Third step: enter the annual mileage3. The Average Annual Vehicle Miles Traveled by Each Vehicle Type

Gasoline DieselDiesel

HEV B20 B100 E85 CNGSchool Bus 30,000 30,000 30,000 30,000 30,000 30,000 30,000Transit Bus 30,000 50,000 50,000 50,000 30,000 30,000 50,000Shuttle/Paratransit Bus 30,000 30,000 30,000 30,000 30,000 30,000 30,000Waste Hauler 23,400 23,400 23,400 23,400 23,400 23,400 23,400Street Sweeper 12,600 12,600 12,600 12,600 12,600 12,600 12,600Delivery Step Van 16,500 16,500 16,500 16,500 16,500 16,500 16,500Transport/Freight Truck 80,000 80,000 80,000 80,000 80,000 80,000 80,000Medium/Heavy Duty Pickup Truck 11,400 11,400 11,400 11,400 11,400 11,400 11,400Maintenance Utility Vehicle 5,000 5,000 5,000 5,000 5,000 5,000 5,000Other 30,000 30,000 30,000 30,000 30,000 30,000 30,000

4. The Average Fuel Economy for Each Vehicle Type in the On-Road Fleet (miles per gasoline gallon equivalent)

Gasoline DieselDiesel

HEV B20 B100 E85 CNGSchool Bus 6.0 7.0 8.5 7.0 7.0 6.0 6.0Transit Bus 2.5 3.0 3.8 3.0 3.0 2.5 2.5Shuttle/Paratransit Bus 7.0 8.0 10.0 8.0 8.0 7.0 7.0Waste Hauler 2.0 2.5 3.0 2.5 2.5 2.0 2.0Street Sweeper 3.0 4.0 5.0 4.0 4.0 3.0 3.0Delivery Step Van 12.0 15.0 18.5 15.0 15.0 12.0 12.0Transport/Freight Truck 5.0 6.0 7.5 6.0 6.0 5.0 5.0Medium/Heavy Duty Pickup Truck 9.0 11.0 13.5 11.0 11.0 9.0 9.0Maintenance Utility Vehicle 20.0 25.0 31.0 25.0 25.0 20.0 20.0Other 2.5 3.0 3.8 3.0 3.0 2.5 2.5

Fourth step: enter the fuel economy

Note: Several fuels to the right of CNG are not shown for clarity in this presentation 29

Fifth step: adjust fuel production assumptions if needed6. Fuel Production Assumptions

Ethanol Feedstock Source 1 1 - Corn 2 - Switchgrass

CNG Feedstock Source 1 1 - North American NG 2 - Non-North American NG

LNG Feedstock Source 1 1 - North American NG 2 - Non-North American NG

LPG Feedstock Source NG Petroleum60% 40%

Source of Electricity for On-Road Electric Vehicles and H2 Electrolysis1 1 - Average U.S. Mix

2 - Average Northeast Mix 3 - Average California Mix 4 - User Defined (go to 'Specs' sheet)

G.H2 Production Process 1 1 - Refueling Station SMR (On-site) 2 - Central Plant SMR (Off-site) 3 - Refueling Station Electrolysis (On-site)

L.H2 Production Process 1 1 - Refueling Station SMR (On-site) 2 - Central Plant SMR (Off-site) 3 - Refueling Station Electrolysis (On-site)

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GREET Fleet Tutorial – Comparing On-Road Vehicle Technologies for Potential Acquisitions

Final step: view petroleum and greenhouse gas results7. Results of On-Road Fleet's Petroleum Usage (barrels)

Gasoline Diesel Diesel

HEV B20 B100 E85 CNG School Bus 0.0 0.0 0.0 0.0 0.0 0.0 0.0Transit Bus 0.0 7687.7 6069.3 6263.0 0.0 0.0 50.8Shuttle/Paratransit Bus 0.0 0.0 0.0 0.0 0.0 0.0 0.0Waste Hauler 0.0 0.0 0.0 0.0 0.0 0.0 0.0Street Sweeper 0.0 0.0 0.0 0.0 0.0 0.0 0.0Delivery Step Van 0.0 0.0 0.0 0.0 0.0 0.0 0.0Transport/Freight Truck 0.0 0.0 0.0 0.0 0.0 0.0 0.0Medium/Heavy Duty Pickup Truck 0.0 0.0 0.0 0.0 0.0 0.0 0.0Maintenance Utility Vehicle 0.0 0.0 0.0 0.0 0.0 0.0 0.0Other 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Fuel Total 0.0 7,687.7 6,069.3 6,263.0 0.0 0.0 50.8

On-Road Fleet Total 20,070.8 barrels of oil

8. Results of On-Road Fleet's Greenhouse Gas Emissions (short tons CO2-equivalent)

Gasoline Diesel Diesel

HEV B20 B100 E85 CNG School Bus 0.0 0.0 0.0 0.0 0.0 0.0 0.0Transit Bus 0.0 4,186.1 3,304.8 3560.8 0.0 0.0 4014.0Shuttle/Paratransit Bus 0.0 0.0 0.0 0.0 0.0 0.0 0.0Waste Hauler 0.0 0.0 0.0 0.0 0.0 0.0 0.0Street Sweeper 0.0 0.0 0.0 0.0 0.0 0.0 0.0Delivery Step Van 0.0 0.0 0.0 0.0 0.0 0.0 0.0Transport/Freight Truck 0.0 0.0 0.0 0.0 0.0 0.0 0.0Medium/Heavy Duty Pickup Truck 0.0 0.0 0.0 0.0 0.0 0.0 0.0Maintenance Utility Vehicle 0.0 0.0 0.0 0.0 0.0 0.0 0.0Other 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Fuel Total 0.0 4,186.1 3,304.8 3,560.8 0.0 0.0 4,014.0

On-Road Fleet Total 15,065.6 short tons of GHG emissions

Vehicle Total

0.020070.8

0.00.00.00.00.00.00.00.0

Note: Several fuels to the right of CNG are not shown for clarity in this presentation

Vehicle Total

0.015065.6

0.00.00.00.00.00.00.00.0

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GREET Fleet Tutorial – Comparing On-Road Vehicle Technologies for Potential Acquisitions

Final Thoughts

When examining your fleet’s petroleum and carbon footprint it is best to understand both the direct impacts from operating the vehicle and the indirect impacts that resulted from producing and transporting the fuel

– The upstream (well-to-pump) activities can significantly affect a vehicle’s footprint, especially those that use alternative fuels

The thought of trying to account for all the issues that go into calculating a vehicle’s footprint may be overwhelming

– However, there are easy-to-use yet robust tools that can help

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Thank you!!!

Argonne National Laboratory’s work is supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy

For additional information contact:aburnham@anl.gov

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