Unit 12.
Eco-selection
and the
Eco-audit tool
Introducing students to life-cycle thinking
Mike Ashby
Department of Engineering
University of Cambridge
© M. F. Ashby, 2011
For reproduction guidance see back page
This lecture unit is part of a set created by Mike Ashby to help introduce students to materials, processes and rational selection.
The Teaching Resources website aims to support teaching of materials-related courses in Design, Engineering and Science.
Resources come in various formats and are aimed primarily at undergraduate education.
www.grantadesign.com/education/resources
Outline






Material consumption and life-cycle

LCA - problems and solutions

Eco-audits and the audit tool

Strategy for materials selection

Demo

Exercises
Resources
Text: “Materials and the Environment”, Chapters 1 - 9
Text: “Materials: engineering, science, processing and design”, 2nd Edition, Chapter 20
Text: “Materials Selection in Mechanical Design”, 4th Edition, Chapter 16
Software: CES EduPack with Eco-Audit tool
Poster: Wall chart of Eco-properties of materials
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Material production
Concern 1: Resource consumption, dependence
96% of all
material
Usage
20% of
Global
energy
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Carbon to atmosphere
Concern 2: Energy consumption, CO2 emission
20% of all
carbon to
atmosphere
M. F. Ashby, 2011
www.grantadesign.com/education/resources
The product life-cycle
Resources
Life cycle
assessment (LCA)
Emissions and waste
M. F. Ashby, 2011
Combust
Landfill
www.grantadesign.com/education/resources
Life cycle assessment (LCA)
ISO 14040 series
PAS 2050
Resource
consumption
Emissions
inventory
Impact
assessment
Typical LCA output
Aluminum cans, per 1000 units
• Bauxite
• Oil fuels
• Electricity
• Energy in feedstock
• Water use
• Emissions: CO2
• Emissions: CO
• Emissions: NOx
• Emissions: SOx
• Particulates
• Ozone depletion potential
• Global warming potential
• Acidification potential
• Human toxicity potential
59
kg
148
MJ
1572
MJ
512
MJ
1149
kg
211
kg
0.2
kg
1.1
kg
1.8
kg
2.47
kg
0.2 X 10-9
1.1 X 10-9
0.8 X 10-9
0.3 X 10-9
Roll up into an
“eco-indicator” ?
Full LCA expensive, and requires great detail and skill – and even
then is subject to uncertainty


How can a designer used these data?
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Design guidance vs. product assessment
Market need
Problem statement
Alternative schemes
Concept
Layout and
materials
Embodiment
CAD, FE analysis,
optimization, costing
Detail
Eco – audit
ability
Product specification
Production
M. F. Ashby, 2011
Life cycle
assessment
www.grantadesign.com/education/resources
Eco-audit for design
Need: Fast Eco-audit with sufficient precision to guide decision-making
 1 resource – energy (oil equivalent)
1 emission – CO2 equivalent
 Distinguish life-phases
16
600
14
C02 equiv (kg)
Energy (MJ)
400
300
200
100
12
10
8
6
4
2
0
0
-2
-100
This is the life-energy and life-CO2
These are potential benefits
(as prescribed in ISO 14040 and PAS 2050)
(could be recovered at end of life)
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Eco-aware design: the strategy (1)
The steps
Fast
eco-audit
Analyse
results, identify
priorities
Explore
options with
“What if..”s
600
600
What if ..
400
400
300
300
Energy (MJ)
Energy (MJ)
Initial design
200
100
200
100
0
0
-100
-100
M. F. Ashby, 2011
Different material?
www.grantadesign.com/education/resources
Eco-aware design: the strategy (2)
Look at the first three steps
The steps
Explore
options with
“What if..”s
Analyse
results, identify
priorities
Fast
eco-audit
Use CES to
select new Materials
and/or Processes
Recommend
actions & assess
potential savings
600
400
Energy (MJ)
Use eco-audit to
indentify
design objective
300
200
100
0
-100
Material
Manufacture
Transport
Minimize:
Minimize:
Minimize:
• material in part
• embodied energy
• CO2 / kg
• process energy
• CO2/kg
• mass
• distance
• transport type
M. F. Ashby, 2011
Use
Minimize:
• mass
• thermal loss
• electrical loss
End of life
Select:
• non-toxic materials
• recyclable
materials
www.grantadesign.com/education/resources
The CES Eco-audit tool
Data from CES
User inputs
User interface
Eco database
 Bill of materials
 Embodied energies
 Manufacturing process
 Process energies
 Transport needs
 CO2 footprints
 Duty cycle
 Unit transport energies
 End of life choice
 Recycling / combustion
Eco audit
model
Outputs
(including
tabular data)
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Typical record showing eco-properties
M. F. Ashby, 2011
www.grantadesign.com/education/resources
The simple Audit tool: Levels 1, 2 and 3
Add record
Eco Audit
Synthesizer
Options….
^ 1. Material, manufacture and end of life ?
1
Component 1
1
Component 2
How
many?
Name
Cast iron
Polypropylene
Choose
material from
CES DB tree
30%
2.4
Casting
Recycle
0%
0.35
Molding
Landfill
Set recycle
content
0 – 100%
Enter
mass
Choose Choose end-ofprocess
life path
v 2. Transport ?
v 3. Use
?
v 4. Report
?
M. F. Ashby, 2011
HELP at
each step
www.grantadesign.com/education/resources
Material and process energy / CO2
Component name
Component 1
Material
Aluminum alloys
Component 2
Component 3
Process
Casting
• Casting
Polymer
molding
• Forging / rolling
• Extrusion
Glass molding
• Wire drawing
• Powder forming
• Vapor methods
Total process energy
Total mass
Polypropylene
Glass
Total embodied energy
CES EduPack
materials
tree
M. F. Ashby, 2011
Available
processes
Mass (kg)
End of life
2.3
Recycle
1.85
Landfill
• Reuse
3.7
• Refurbish
• Recycle
Reuse
• Combust
• Landfill
Total end of life energy
End of life
options
www.grantadesign.com/education/resources
Transport
Transport stage
Transport type
Stage 1
32 tonne truck
Stage 2
Sea freight
Distance (km)
350
12000
Transport energy
Transport CO2
Table of transport types:
MJ / tonne.km
CO2 / tonne.km
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Use phase – static mode
Energy input and output
Power rating
Usage
Usage
Fossil fuel to electric
1.2
kW
W
days per year
kW
MW
hours
0.5
hpper day
ft.lb/sec
Total energy and
CO2 for
kCal/yr
BTU/yr
365
Energy conversion path
Fossil fuel to heat, enclosed system
Fossil fuel to heat, vented system
Fossil fuel to electric
Fossil fuel to mechanical
Electric to heat
use
Electric to mechanical (electric motor)
Electric to chemical (lead-acid battery)
Electric to chemical (Lithium-ion battery)
Electric to light (incandescent lamp
Electric to light (LED)
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Bottled water (100 units)
 1 litre PET bottle with PP cap
 Blow molded
 Filled in France, transported 550 km to UK
 Refrigerated for 2 days, then drunk
Number
Name
100
Bottles
100
Caps
100
Water
Material
Process
Mass (kg)
End of life
PET
Molding
0.04
Recycle
Polyprop
Molding
0.001
Recycle
1.0
Transport
Stage 1
14 tonne truck
550 km
Use - refrigeration
Fossil to electric
M. F. Ashby, 2011
0.12 kW
2 days
24 hrs/day
www.grantadesign.com/education/resources
The output: drink container
400
The audit reveals
the most energy
and carbon
intensive steps…
Energy (MJ)
300
200
100
End of life
0
Material Manufacture Transport
-100
Use
… and allows rapid
“What if…”
100% virgin PET
with recycling
-200
12
10
Carbon (kg)
8
6
4
2
End of life
0
Material Manufacture Transport
-2
-4
100% virgin PET
with recycling
Use
PET
Glass ?
-6
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Change the materials
 1 litre glass bottle with aluminum cap
 Glass molded
 Filled in France, transported 550 km to UK
 Refrigerated for 2 days, then drunk
Number
Name
Material
Process
100
Bottles
Soda
glass
PET
Glass
mold
Molding
100
Caps
Aluminum
Polyprop
Rolling
Molding
100
Water
Mass (kg)
End of life
0.45
0.04
Recycle
0.002
0.0001
Recycle
1.0
Transport
Stage 1
14 tonne truck
550 km
Use - refrigeration
Fossil to electric
M. F. Ashby, 2011
0.12 kW
2 days
24 hrs/day
www.grantadesign.com/education/resources
Glass bottle replacing PET
Change
of scale
600
200
400
100
End of life
0
Material Manufacture Transport
-100
End of life
0
Material Manufacture Transport
-200
100% virgin PET
with recycling
Use
100% virgin glass
with recycling
-400
12
Change
of scale
10
60
50
40
6
4
2
End of life
0
Material Manufacture Transport
Carbon (kg)
8
30
20
10
End of life
0
Material Manufacture Transport
Use
Use
-10
-2
-4
200
Use
-200
Carbon (kg)
800
300
Energy (MJ)
Energy (MJ)
400
100% virgin PET
with recycling
-6
M. F. Ashby, 2011
-20
-30
100% virgin glass
with recycling
www.grantadesign.com/education/resources
400
300
300
200
200
100
Material Manufacture Transport
-100
Carbon (kg)
End of life
0
Energy (MJ)
400
100
0
Material Manufacture Transport
Use
-100
100% virgin PET
with recycling
-200
-200
12
12
10
10
8
8
6
4
2
End of life
0
Material Manufacture Transport
-2
-4
100% virgin PET
with recycling
-6
M. F. Ashby, 2011
Use
Carbon (kg)
Energy (MJ)
Use recycled PET instead of virgin?
Use
End of life
100% recycled PET
with recycling
6
4
2
0
Material Manufacture Transport
Use
End of life
-2
-4
100% recycled PET
with recycling
-6
www.grantadesign.com/education/resources
Is it practical to use recycled PET?
M. F. Ashby, 2011
www.grantadesign.com/education/resources
400
300
300
200
200
100
Material Manufacture Transport
-100
Carbon (kg)
End of life
0
Energy (MJ)
400
100
Material Manufacture Transport
-100
100% virgin PET
with recycling
-200
-200
12
12
10
10
8
8
6
4
2
End of life
0
Material Manufacture Transport
Use
100% virgin PET
with combustion
6
4
2
0
Material Manufacture Transport
Use
Use
End of life
-2
-2
-4
End of life
0
Use
Carbon (kg)
Energy (MJ)
Combust instead of recycle
100% virgin PET
with recycling
-6
M. F. Ashby, 2011
-4
-6
100% virgin PET
with combustion
www.grantadesign.com/education/resources
Ship by air freight, refrigerate 10 days
1000
400
Change
of scale
300
800
Disposal
0
Material Manufacture Transport
-100
Use
400
200
-200
100% virgin PET
with truck transport
-200
-400
12
60
Change
of scale
8
6
4
2
Disposal
0
Material Manufacture Transport
Use
-2
-4
100% virgin PET
with truck transport
-6
M. F. Ashby, 2011
Disposal
0
Material Manufacture Transpt
10
Carbon (kg)
Energy (MJ)
100
Carbon (kg)
Energy (MJ)
600
200
Use
100% virgin PET
with air freight
50
40
30
20
10
Disposal
0
Material Manufacture Transpt
Use
-10
-20
100% virgin PET
with air freight
-30
www.grantadesign.com/education/resources
Teaching with the CES Eco-audit tool
Introductory level teaching
• Overview of the life cycle
• Shown how Eco Audit Tool works
• Pre-loaded projects
Pre-loaded in CES Edu 2011
 Bottled mineral water.prd
 Hair dryer.prd
 Electric kettle.prd
Which life phase dominates?
 Portable space heater.prd
What could you do about it?
 Family car.prd
• Self-made projects
 Wind turbine.prd
Students can explore change of
 Material
 Recycle content
 Transport mode
 Transport distance
 Use pattern
 Electric energy mix
 End of life
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Jug kettle
Bill of materials and processes
2 kW jug kettle
 Made SE Asia
 Air freight to UK
 Life: 3 years
Transport
 12,000 km, air freight
 250 km 14 tonne truck
M. F. Ashby, 2011
Use
 6 minutes per day
 300 days per year
 3 years
www.grantadesign.com/education/resources
Eco audit: the jug kettle
What do we learn?
 Little gained by change of material for its own sake
 Much gained by insulation – double wall with foam or vacuum
 Or make hot water on the fly – only as much as needed
M. F. Ashby, 2011
www.grantadesign.com/education/resources
The enhanced Audit tool: Eco Design
Add record
Eco Audit
Same as the
simple model
Synthesizer
Options….
^ 1. Material, manufacture and end of life
1
Component 1
?
Cast iron
30%
2.4
Casting
Fine machining
10%
Recycle
95%
Joining and finishing
v 2. Transport
Component 1
Painting
0.55
m2
Component 1
Welding
0.7
m
?
Choose joining
(adhesives, fastners,
welding)
v 3. Use
v 4. Report
?
and finishing
(painting, plating,
powder coating)
?
M. F. Ashby, 2011
Machining,
grinding, %
removed
% recovered
at end of life
Set
parameters
For advanced teaching the Enhanced
Eco Audit Tool is available in the Eco
Design Edition of CES EduPack
www.grantadesign.com/education/resources
So what?
CES has two tools-sets to help explore the materials dimension of
environmental design
Tool 1. Eco-audits allows students to implement quick, approximate
“portraits” of energy / CO2 character of products.
Tool 2. Selection strategies allows selection to re-design products to meet
eco-criteria, using systematic methods
They allow fast audits and systematic materials selection for redesign
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Lecture Unit Series
These PowerPoint lecture-units are on the Teaching Resource Website
Each frame of each unit has explanatory notes. You see them by opening the
PowerPoint slide in Notes view (View – Notes pages) or by clicking this icon in the
bottom toolbar of PowerPoint
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Also Available for Sustainability
On the topics of:
Eco Design & Eco Audits
Low Carbon Power Systems
•
•
•
•
•
•
•
•
•
Exercises with Worked Solutions
Other Lecture Units
White Papers
Interactive selection case studies
Webinar recording
Poster
Sample Eco Audit Project Files
Links to other good resource sites
Eco Indicator Database
http://teaching.grantadesign.com/open/eco.htm
M. F. Ashby, 2011
www.grantadesign.com/education/resources
Reproduction
Author
This work is licensed under a Creative Commons
Attribution-NonCommercial-ShareAlike 3.0 Unported
License.
Professor Mike Ashby
University of Cambridge, Granta Design Ltd.
www.grantadesign.com/education
www.eng.cam.ac.uk
Please make sure that Mike Ashby and Granta Design are
credited on any reproductions. You cannot use this resource
for any commercial purpose.
The Granta logo, the Teaching Resources logo and laptop
image and the logo for the University of Cambridge are not
covered by the creative commons license.
http://creativecommons.org/licenses/by-nc-sa/3.0/
Accuracy
We try hard to make sure these resources are of a high quality. If you have any suggestions for improvements, please contact us
by email at teachingresources@grantadesign.com
M. F. Ashby, 2011
Granta’s Teaching Resources Website aims to support teaching of materials-related courses in Engineering, Science and Design.
The resources come in various formats and are primarily aimed at undergraduate students.
This resource is one of 23 lecture units created by Professor Mike Ashby.
The website also contains resources donated by faculty at the 800+ universities and colleges worldwide using
Granta’s CES EduPack.
The teaching resource website contains both resources that require the use of CES EduPack and those that don’t.
Some of the resources, like this one, are open access.
www.grantadesign.com/education/resources
M. F. Ashby, 2011
www.grantadesign.com/education/resources