1

Hybrid LCA Models

2

Admin Issues

• Next 2 weeks:– Heather, me, others out of town– 3 guest lectures (hybrid methods and

uncertainty)

• Last week of class - choice:– Group presentations (if so, how/when)– Or other course content

• Eg impact assessment, others

3

Advantages of Conventional LCA vs. EIO-LCAConventional LCA EIO-LCA

• Detailed process-specific

analyses

• Specific product comparisons

• Process improvements/weak

point analyses

• Future product development

assessments

• Economy-wide, comprehensive assessments

(all direct and indirect environmental effects

included)

• Sensitivity analyses/scenario planning

• Publicly available data, reproducible results

• Future product development assessments

• Information on every commodity in the

economy

4

Disadvantages of Conventional LCA vs. EIO-LCA

Conventional LCA EIO-LCA

• System boundary setting

subjective

• Tend to be time intensive

and costly

• New process design

difficult

• Use of proprietary data

• Cannot be replicated if

confidential data are used

• Uncertainty in data

• Some product assessments contain

aggregate data

• Process assessments difficult

• Difficulty in linking dollar values to

physical units

• Economic and environmental data may

reflect past practices

• Imports treated as U.S. products

• Difficult to apply to an open economy (with

substantial non-comparable imports)

• Non-U.S. data availability a problem

• Uncertainty in data

5

Models of LCA

• “Conventional” LCA, developed by SETAC and EPA, based on process models

• Economic input-output analysis-based LCA (EIO-LCA), developed by Carnegie Mellon’s Green Design Initiative and Others

• Hybrid models:– Using eiolca model to guide boundary and scope of process models.– Disaggregating or augmenting io model.– Using eiolca for some processes, products and supply chain elements (where

sector aggregation is not a major issue), with process models for remainder.

– There are more/other ways, including more “rules” but we save those for the Advanced LCA course (Mini 4).

6

Utility of Two LCA Approaches

EIO-LCASETAC-EPA

LCA

SETALCESETACLCA

range of information for product design

industry wide

interindustrial

specificprocesses

specific materials

productssystems

7

Goals of Hybrid LCA Models• Incorporate the advantages of the two models,

reduce disadvantages

• Include detailed, process-level data, as well as the economy-wide effects

• Provide environmental and economic information about every major product and process in the economy

• Quantify the widest range of environmental data

• Two obvious high level alternatives for hybrid models

8

Integration of EIO-LCA Data into Conventional LCA

C11 Cn

C1

Cn

system boundary

commodity

commodity

Process models

EIO-LCA

9

Integration of Conventional LCA Data into EIO-LCA

EIO-LCA

process results

product

commodity

commodity

Cj

Cj1 Cj2

10

User Adjustments

• Many adjustments possible due to known aggregation or emissions problems– Hybrid models including EIO and process models.– Parameter adjustments to reflect non-linearities.– Disaggregating individual EIO sectors.

• Bayesian methods applicable here – adjusting estimates based on expectations.

• Multiple approaches: EIO-LCA and Conventional LCA.

11

In-Class Exercise: Hybrid LCA of Electricity Generation

• Make a slightly improved (hybrid) LCA model for PA electricity using:– National EIO-LCA results ($1M of power gen

results, handed out)– National and PA Grid Mixes:

US PA

Coal 50% 58%

Nuclear 19% 37%

Nat Gas 19% 2%

Other 12% 3%

12

Things to Think About

• Price assumption (how much per kWh?)

• Adjustments needed

• Assumptions needed

• IF you wanted more data, what would it be? (But only use what is above)

• Estimate power plant-only and supply chain wide CO2 emissions / kWh

13

Post-Exercise

• This was a very simple (but real) hybrid exercise.

• Might think about what would be needed to integrate NREL LCI data on energy sectors with EIO-LCA power gen sector

14

Economic and Environmental Implications of Online

Retailing and Centralized Stock Keeping in the United

States

15

E-Commerce Retail Quarterly Volume ($B)

16

Traditional Retail Logistics System

• Factory to warehouse to warehouse to retailer.

• Last leg of trip by private vehicle

17

Single Facility Sales

• LL Bean, Lands End - catalogue sales

• Amazon (original), MusicOutpost - web based sales from a single facility

18

Comparison of Freight Modes

0

10

20

Total Energy (TJ/$1M) Direct Energy(TJ/$1M)

Total Energy (MJ/ton-mile)

Direct Energy (MJ/ton-mile)

Air

Truck

Rail

19

How to Model E-Commerce for LCA?

20

Book Publishing Case Study

• Traditional System:– logistics: printer > warehouse > warehouse >

retailer > home, all by truck/car– unsold returns - roughly 35% for bestsellers

• E-commerce System:– logistics: printer > warehouse > distribution

center >home, by air and truck.– No unsold returns

21

Comparative Analysis: * is EIOLCA Sector Use

• Traditional:– truck transport (1000 mi)*– Warehousing*– production of returns*– reverse travel of returns*– private automobile

transport

• E-Commerce– air transport (500

mi)*– truck transport (500

mi)*– Warehousing*

22

Comparative Costs ($ 1000s for

$ 1 M or 290,000 books) Traditional E-Commerce

W/o Returns or Auto

700 992

W Returns but w/o Auto

1,300 992

W/o Returns but w/ Auto

1,170 992

W returns and auto

1,780 992

23

Why are E-Commerce Costs Lower?

• Higher transportation costs for e-commerce, but:– Returns of unsold copies – Lower retail transactions costs– Lower (private) automobile cost

• Result is cost advantage for e-Commerce

24

Energy(TJ)

*ConventionalAir Pollutants

(mT)

RCRAHazardousWaste (mT)

GreenhouseGas Emissions(CO2 Equiv.,

mT)

Trucking (with returns) 5.3 8.9 9.1 354

Production 9.45 8.1 23 612Packaging 1.2 1.1 3.5 84Passenger Trips 9.7 42 0 611Pass. Fuel Prod. 7 1.7 30 337Total 33 62 66 2000

Trucking 1.2 2 2 80Air 7 3 9 440Production 7 6 17 453Packaging 4 3 11 254Delivery Trips 11 18.5 19 736Pass. Fuel Prod. 0 0 0 0Total 30 33 58 1963% Difference 9 47 12 2

25

Summary Environmental Impacts

(per-book basis)

Trad. E-Com.

Energy (MJ) 115 105

Conventional Air (kg) 0.2 0.1

Hazardous Waste (kg) 0.2 0.2

Greenhouse Gas (kg) 7 7

26

Sensitivity Analysis

• ‘Traditional’ becomes better if:– Local distance to bookstore < 3 miles– Air transport of books > 700 miles– Orders not shipped together

• Ecommerce better if:– Switch from Air transport– Multiple origin sites– Greater density of sales.

27

Harry Potter Case

• 250,000 books shipped on release date by Amazon.com– 9,000 trucks and 100 airplanes

• 2.5 lb. book, 0.7 lb. packaging (3.2 lbs.)– Bookstores got 10 per box

• Shopping trips for books avg. 11 miles– Marginal effects

28This is Research….

29

Some Analysis Issues

• What are E-commerce future scenarios?• What will happen with local manufacturing

technology?• What will be impact of new business

models for controlling inventory (warehousing), manufacturing and shipping.

• What is appropriate time scale of analysis?

30

Analysis Boundary Issues (cont.)

• Buildings - decrease in retail or warehouse space?

• Shopping - will individuals substitute other travel for reduced shopping travel?

• Computers - what fraction of personal computer burdens should be allocated to E-commerce?

31

Will E-commerce Improve or Degrade the Environment?

• Net Effect - hypothesis: depends upon product and processes and upon the analysis boundary.

• Appropriate Public Policy - – Don’t ignore service industries in environmental

policy.– Consider life cycle costs including social costs.– Take advantage of cost savings to create

environmental benefits

32

Quick tutorial - EIO-LCA Spreadsheet Models