impacts of modeling choices versus data updates in a large ...€¦ · the world’smost consistent...

Trust in Transparency! 1

Impacts of modeling choices versus

data updates in a large data system

LCAXV, Vancouver

06 October 2015

Gregor Wernet Bernhard Steubing

Executive Manager Senior Research Associate & ecoinvent LCI Expert

ecoinvent ETH Zurich

The world’s most

consistent and

transparent Life Cycle

Inventory database

Impacts of modeling choices versus

data updates in a large data system

LCAXV, Vancouver

06 October 2015

Gregor Wernet Bernhard Steubing

Executive Manager Senior Research Associate & ecoinvent LCI Expert

ecoinvent ETH Zurich

Trust in Transparency! 3

What is ecoinvent?

• ecoinvent is a not-for-profit association created by 5 Swiss

research institutes

• Publishes, maintains and updates the ecoinvent database

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ecoinvent – Quality Features

• Consistent

Fully interlinked database

• Reliable

Independent expert review for all data

Continuously developed and improved over 15 years

• Transparent

Full access to both unit process data and all calculation results

Individual documentation of each dataset

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Development of version 3

• Develop the database into a global database

Change in scope

• Allow more flexibility for the users

More access to the underlying modelling

Flexibility in modelling choices

• Many data updates in the 3 years between version 2.2 and 3.0

• Combination of several methodological updates and many data

updates makes it difficult to understand the differences!

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Version 2.2 vs Version 3 (cut-off)

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Some changes with version 3

• Waste flows with mass

• System models

• Global supply chains

• Consumption mixes and markets

• Update of transport data

• Data updates

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System models in ecoinvent v3

• Allocation, Recycled Content cut-off

• Allocation at the point of substitution (APOS)

• Consequential (long-term, small-scale)

• The cut-off model is identical to v2.2 in its approach

Only minor consistency corrections affecting individual datasets

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Cut-off vs APOS

• Difference in allocation of wastes treatment products and

recyclable materials

No other differences in the models

• Differences only for these products

8% of products in the database are wastes, few have significant by-

products in treatment

2% of products in the database are recyclable materials

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Cut-off vs APOS

APOS divided by Cut-off

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Some features of version 3

• Waste flows with mass

• System models

• Global supply chains

• Consumption mixes and markets

• Update of transport data

• Data updates

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Global supply chains

• In v2.2, local datasets served as placeholders for global

activities

• All processes now have a global counterpart

Often extrapolated from regional data

Uncertainties increased

Distributes supply chains and impacts for regionalized LCIA

Serves as a foundation for regional data collection projects

• Supply chains can access these globalized sources

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• Comparison of Cut-off results v2.2 vs v3.1

• Globalized supply chains more relevant in v3.1

Impacts in e.g. China more accurately reflected

Global supply chains

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• Changes in allocation method

Switch from mass to economic allocation

• Not a violation of the ISO principles, only for datasets where

there is no physical relationship between mass and the process

drivers.

Most physical properties are not allocation-relevant

Example: Lithium chloride electrolysis

Data updates - allocation

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• Some datasets were restructured

e.g. port maintenance is now included in the port infrastructure

Impacts significantly increased over the lifetime of the port

Burden of transition to new modelling, but significantly easier to use

datasets for the practitioner

• Many datasets were simply improved and expanded

Updated data can improve – or get worse – LCIA results

• Introduction of new consumption mixes has impacts on individual

datasets

• Thousands of datasets were updated for version 3, and no single

change can explain a large part of the differences between versions

Data updates - restructuring

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Data updates - Transport

• Global update of freight transport data

Based on sector-specific transport statistics

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Some features of version 3

• Waste flows with mass

• System models

• Global supply chains

• Consumption mixes and markets

• Update of transport data

• Data updates

Trust in Transparency! 18

Conclusions

• Differences between ecoinvent versions 2 and 3 can be difficult to

explain due to the many changes introduced with version 3

• Several methodological changes and also some data projects have

had no or barely any effect on results

Waste modelling, System model implementation, Transport data

• The expansion of the database towards global supply chains has

corrected serious issues with supply chains as well as distributions

of impacts

• Data updates and additions are the main reason for significant

changes in version 3

The world’s most

consistent and

transparent Life Cycle

Inventory database

Thank you for your attention!