Incorporating Uncertainty Analysis, Spatial Resolution, and Temporal Resolution in Life Cycle Assess

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Incorporating Uncertainty Analysis, Spatial
Resolution, and Temporal Resolution in Life Cycle
Assessment

• Shannon M. Lloyd
• Lanka W. Thabrew
• Robert J. Ries
• Department of Civil Environmental Engineering
• University of Pittsburgh

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Life Cycle Assessment
Goal and scope
Inventory(LCI)
Interpretation
Impact(LCIA)
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Common Approach to LCA
Use deterministic models to calculate inventory
Fails to capture the variability and uncertainty
in input data, normative choices, and
mathematical relationships
Aggregate inventory across life cycle (space and
time)
Isolates the analysis from its context (e.g.,
varying intensities of resource use, releases,
and impacts)
Estimate potential impact based on average
characterization factors
Local, regional, national, or global
characterization factors may be more appropriate
for some impacts
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Common Approach to LCA

• Questions
• How reliable are LCA results?
• How meaningful are LCA comparisons?
• Decision Makers
• Uncertainty in and divergence between LCA
  outcomes
• An understanding of spatial and temporal
  tradeoffs

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Proof of Concept LCA modelunder uncertainty with
temporal and spatial resolution

• Application
• Residential buildings in Pittsburgh, PA
• Operational impacts, e.g., water heating
• Inventory
• Air emissions
• Geographical inventory
• Temporal scale (varying intensities)
• Modeling Software
• Analytica (hierarchical nested modules and Monte
  Carlo simulation)

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Hierarchy of Nested Modules
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Hierarchy of Nested Modules
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Hierarchy of Nested Modules
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Hierarchy of Nested Modules
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Modeling Water Use

• References
• Lutz et al., "Modeling Patterns of Hot Water Use
  in Households," Ernest Orlando Lawrence Berkeley
  National Laboratory, LBL-37805 Rev., November
  1996.
• Pinckard et al., "Documentation of Calculation
  Methodology and Input Data for the Home Energy
  Saver Web Site," Ernest Orlando Lawrence Berkeley
  National Laboratory, November 2003.

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Average Modeled Water Use
Liters
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Modeling Energy Use per Hour PGE Model

• Reference
• Pacific Gas and Electric Company, "Code Change
  Proposal for Hourly Water Heating Calculation",
  Draft May 15, 2002.

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Modeling Energy Use Per Hour LBL Model

• Reference
• Pinckard et al., "Documentation of Calculation
  Methodology and Input Data for the Home Energy
  Saver Web Site," Ernest Orlando Lawrence Berkeley
  National Laboratory, November 2003.

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Hot Water Thermal Energy Consumption
kJ
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Residential Natural Gas Life Cycle
At or near wellhead
Nat gas extraction
Separation (oil condensate)
Liquid water removal
Between wellhead and plant
Gathering pipes
Centralized processing plant
Water vapor removal
Separation of natural gas liquids
Sweetening
Between processing plant and consumers
Residential
Combustion
Interstate intrastate pipelines
Storage, compressor stations, liquid separators,
metering stations, valves
Distribution system
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Natural Gas Flow in the U.S
Source Energy Information Administration/Natural
Gas Annual 2003
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Abbreviated Natural Gas Pipelines to SW PA
PA
WV
KY
TN
MS
AL
TX
LA
Gulf of Mexico
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Abbreviated Natural Gas Pipelines to SW PA
PA
WV
KY
TN
MS
AL
TX
LA
Gulf of Mexico
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Abbreviated Natural Gas Pipelines to SW PA
PA
WV
AL
TX
LA
Gulf of Mexico
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Assumed Natural Gas Origination
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Methane Emissions

• Interstate movements of natural gas by state
• Natural gas dry production by state
• Distance between the geographic centers of states
• Geographic size of state

Methane emissions per volume natural gas distance
traveled

• Natural gas composition

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Uncertainty - Annual Methane Emissions
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Life Cycle Impact Assessment (LCIA)

• Impact of methane expressed with a
  characterization factor (CF) developed in the
  IMPACT 2002 program in ethylene eq. / kg
• Source IMPACT 2002 version 2.0 (March 2004)
  (Pennington et al. 2003), (Goedkoop and Spriensma
  2000), (Guinée et al. 2002) and IPCC
• Traditional LCIA
• Impact SCFi Releasei

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Spatial and Temporal LCIA

• Tropospheric Ozone Impact Model
• The effect of weather variability is expressed as
  ozone formation potential
• Calculated based on three hourly parameters for
  weather
• relative humidity
• temperature
• windspeed
• Reference Chock et al. "An Analysis of Trends in
  Oxidant Air Quality in the South Coast Air Basin
  of California." Atmospheric Environment 16 (11)
  pp. 2615-2624, 1982
• Impact SCFi Releasei ozone formation
  potentiali

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Traditional LCIA Annual
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Spatial and temporal LCIA Annual
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Traditional LCIA Annual
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Spatial and temporal LCIA Annual
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Traditional/Spatial and temporal LCIA Annual
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Traditional LCIA Daily
On a typical day in July
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Spatial and temporal LCIA Daily
On a typical day in July
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Traditional/Spatial and temporal LCIA Daily
On a typical day in July
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Annual Impact
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Next Steps

• Additional analysis of intermittent building
  systems
• Explore the use of ArcView for visual
  representation
• Evaluate temporally and spatially informed
  methods for non-point emissions
• Develop additional temporally and spatially
  informed characterization factors
• Compare results to aggregated LCIA
• Compare results to average characterization
  factors

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Publications and presentations

• Survey of quantitative approaches for
  characterizing, propagating, and analyzing
  uncertainty in life cycle assessment, accepted,
  Journal of Industrial Ecology.
• Incorporating spatial and temporal resolution in
  the life cycle inventory of residential buildings
  using hierarchical modules, in Dynamics of
  Industrial Ecosystems edited by Matthias Ruth and
  Brynhildur Davidsdottir.
• Incorporating uncertainty analysis, spatial
  resolution, and temporal resolution in
  environmental life cycle assessment, presented
  to the National Risk Management Research
  Laboratory, U.S. Environmental Protection Agency,
  Cincinnati, OH, May 17.
• Incorporating uncertainty analysis, spatial
  resolution, and temporal Resolution in life cycle
  assessment of residential buildings, presented
  at the third International Conference of the
  International Society for Industrial Ecology,
  June 12-15.

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Contact Information
Shannon M. Lloyd sml_at_firstenvironment.com Lanka
W. Thabrew lwt1_at_pitt.edu Robert J.
Ries robries_at_pitt.edu