Lifecycle Modeling

EPA Modeling WorkshopEPA Office of Mobile SourcesMay 26, 1999

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

What is lifecycle modeling?

Spreadsheet-based computer modelAccounts for all energy and emissions,

throughout a production processFor fuels, this includes:

fuel feedstock production feedstock transport fuel processing fuel distribution to the retail outlet

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Gasoline Production Process

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Ethanol Production Process

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Lifecycle modeling goals

Incorporate entire production process “explicitly recognizes connections between all

dimensions”

Identify key processes, emission sourcesAllow equitable comparison between

products (i.e. fuels)Suggest areas for improvementflexible and user-friendly

U.S. Environmental Protection AgencyU.S. Environmental Protection AgencyHow is lifecycle modeling done?

Data is gathered, or assumed, for each step in each process

Equations are compiled to account for entire process for each product

Tracks all materials in and outAccounts for emissions and energyResults depend on input data,

variables, and assumptions

U.S. Environmental Protection AgencyU.S. Environmental Protection AgencyLifecycle Modeling - EtOH example

EthanolEthanolProcessingProcessing

Ethanol FuelEthanol FuelDistributionDistribution

Corn FermentationCorn FermentationCoal/Corn Stover Coal/Corn Stover Process EnergyProcess EnergyElectricityElectricity

OutputsOutputs

CornCornTransportTransport

RenewableRenewableEthanol TruckEthanol Truck

Diesel trucksDiesel trucks

Corn Corn FarmingFarming

CornCornP:N:K FertilizerP:N:K FertilizerDiesel farm equip.Diesel farm equip.

U.S. Environmental Protection AgencyU.S. Environmental Protection AgencyApproaches to lifecycle modeling

Users?Users?

Purpose?Purpose?

SuggestSuggestImprovement?Improvement?

Model inputs?Model inputs?

Model outputs?Model outputs?

Scope?Scope?

Policy analysts

Make general comparisonsbased on industry averagesor assumptions of future

No

industry-wide estimates

industry-wide projections forfuel/feedstock combinations

life-cycle including fuelcombustion in vehicle

Current

U.S. Environmental Protection AgencyU.S. Environmental Protection AgencyApproaches to lifecycle modeling

Users?Users?

Purpose?Purpose?

SuggestSuggestImprovement?Improvement?

Model inputs?Model inputs?

Model outputs?Model outputs?

Scope?Scope?

Policy analysts

Make general comparisonsbased on industry averagesor assumptions of future

No

industry-wide estimates

industry-wide projections forfuel/feedstock combinations

life-cycle including fuelcombustion in vehicle

fuel producers

To track actual emissionsof individual fuel plants

Yes

actual data for indiv plants

plant-specific GHG emissionsassoc with individual plants

life-cycle excluding fuelcombustion in vehicle

Current NEWNEW

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Data Needs

Wide range of data needed, and sourcesNot always readily available

data not measured or recorded confidentiality issues

Varies somewhat, depending on approach

Varies by fuel Varies by process step

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Data Needs By Step:

Feedstock development most complicated step not directly controlled by fuel producers probably cannot rely totally on national

defaultsFeedstock Trans - national ave, or regionalFuel Processing - controlled by producerFuel Distribution - minor, base on estimates

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Electricity Production Process

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Modeling Issues

Complexity, level of detailData sources

determining best sources how much to estimate how to ensure accuracy

Handling of secondary fuels usedSynergistic impact of upstream and

downstream changes

U.S. Environmental Protection AgencyU.S. Environmental Protection Agency

Questions for Stakeholders

What are the goals for lifecycle modeling of alternative fuels?

What are the best available data sources?

How do we standardize methodology?How do we ensure accuracy?How can lifecycle modeling inform

policy decisions?