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Sustainable Engineering Issues and Approaches

Chris Hendrickson

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Sustainability• Many (>350?) definitions of Sustainability.

– Mainstream goal, but underlying this consensus are very different belief systems

– What is planning horizon? 4 years, 100 years, 1000 years, …• ‘Meet the needs of the present without compromising the

ability to meet the needs of future generations.’– Bruntledge Commission (1997) reconciling goals of

environmental protection and poverty elimination. – Egalitarian viewpoint of equal outcomes– Technological progress may negate concern.

• ‘design..within realistic constraints such as…sustainability.’ – Required eng. graduate ability in US engineering accreditation, ABET.

C3

Slide 2

C3 1. Bruntledge ReportChris Hendrickson, 8/23/2006

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One Approach: Triple Bottom Line for Sustainability

• Economic: effective investments (eng. econ.), essential finance, job creation, competitiveness

• Environmental: natural systems, public health– Reduce use of non-renewable resources– Better manage use of renewable resources– Reduce the spread of toxic materials.

• Social: equity, justice, security, employment, participation

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Numerous Environmental Issues

• Global climate change• Spread of toxic materials:

– Conventional air and water pollutants– Organic materials such as endochrine

disrupters– Nano-materials

• Dwindling biodiversity• Overuse of common resources such as

fisheries.

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Grinnell Glacier, 1900-1998, Montana

Source: usgs

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Triple Bottom Line Assessment Analytical Difficulties

• Multi-objective problem – many dimensions of impact.

• Valuation problems for many items.• Priorities differ among stakeholders (such

as stockholders…)• Trade-off and dominance analysis

relevant.• Role of precautionary principle – do not

risk irreparable harm.

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Valuation Example: Economic Sectors with Highest % of External Air Emissions Costs

Commodity Sector Total DirectCarbon black 87% 82%Electric services (utilities) 34% 31%Petroleum / natural gas well drilling 34% 31%Petroleum / gas exploration 31% 29%Cement, hydraulic 26% 19%Lime 22% 16%Sand and gravel 20% 16%Coal 19% 15%Products of petroleum and coal 18% 12%Primary aluminum 15% 6%Average over all 500 sectors 4% 1%

Ref.: H. Scott Matthews, PhD Dissertation. 1992 Data.

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Sustainability Metric Examples

• Environmental: Greenhouse Gas Emissions, Primary Energy Use, Land Disruption.

• Social: Employment, Income, Government Revenue

• Financial: Profits, Export Potential, Import Penetration

• Source: Balancing Act: A Triple Bottom Line Analysis of the Australian Economy

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Sustainable Engineering: Examples of Heuristics

• Energy reduction over lifecycle (correlation with many environmental indicators)

• Reduce packaging and other material waste over lifecycle

• Reduced use of toxics

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Example: Power Tool Datalogger

Connectionto an LED fordata transmission

power supply

Connections to sensors

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Datalogger Triple Bottom Line

• Permits profitable re-manufacturing to replace loss making recycling.

• Develops information on tool use.• Reduces material use overall.• Creates new low-cost tool option.• No privacy issues raised (unlike autos!)• Must balance cost of datalogger versus

benefits – return rate of used power tools is critical.

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Coming Sustainable Engineering Information Technology

• Structural health monitoring.• Toll collection and infraction identification.• Operational monitoring and improvement.• Multi-tasking: wireless communications.• Quality and security monitoring.• Etc.

Power Tool Datalogger Primitive by Comparison

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Life Cycle Perspective

• Products may exist for a long period of time (e.g. infrastructure)

• Products and services may have substantial (global) supply chain.

• Focusing upon one life cycle phase can be misleading – minimizing design or construction costs can increase life cycle costs, even when discounted.

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Residential Life Cycle Energy

1509 1669

14493

4725

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0

2000

4000

6000

8000

10000

12000

14000

16000

18000

Standard Efficient

Ener

gy C

onsu

mpt

ion

(GJ)

DemolitionUseFabrication

Source: Ochoa, Hendrickson, Matthews and Ries, 2005

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Motor Vehicle Energy Use

1053310800 95418

1100211

413337215160676191432

0

200000

400000

600000

800000

1000000

1200000

Manufac

ture

Operatio

nPetro

leum R

efining

Repair

Fixed C

osts/In

suranc

e

Vehicle Life Cycle Stage

Ene

rgy

Use

(MJ)

SuppliersIndustry/Vehicle

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Life Cycle AnalysisExtraction to End of Disposal

Need to Account for Indirect Inputs

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Some Tools (Continued)

• Triple bottom line assessments (multi-objective optimization)

• Life Cycle Analysis• Design heuristics and standards.• Wider range of design alternatives (not a

tactic limited to sustainable engineering, of course…)– New technology (datalogger, new materials)– Alternative approaches (different modes)

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Example: Producing Electricity in Remote Locations

• 52% of electricity is produced from coal• Coal deposits are generally not close to

electricity demand• The Powder River Basin produces more

that 1/3 of U.S. coal, 350 million tons shipped by rail up to 1,500 miles

• Should PRB coal be shipped by rail?

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Alternative Shipment Methods

• Coal by rail• Coal by truck or waterways (non-starters!)• Coal to electricity and ship by wire• Coal to gas and ship by pipeline• Coal to gas and ship by wire• Beyond scope of example: move demand,

reduce demand, alternative energy sources

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Wyoming to Texas Coal Transport

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0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

1,600,000

1,800,00019

90

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Year

Frei

ght (

mill

ion

ton-

mile

s)

TruckRailroad

US Freight Traffic is Increasing

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Rail Mileage is Declining

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

1980 1990 1994 1995 1996 1997 1998 1999 2000

Year

Mile

s of

Rai

lroa

d O

wne

d

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Leading to Heavier Use and Productivity per Rail Mile

0

20

40

60

80

100

120

140

16019

90

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

Rela

tive

Chan

ge (1

990=

100)

Truck (ton-mi)Railroad (ton-mi)Roadway lane-milesTrack rail-miles

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Transporting Energy from WY to Texas: All New Infrastructure

0

50

100

150

200

250

300

350

400

450

Capital O&M Fuel Externalities Total

Ann

ual C

ost (

$mill

ion)

Coal by Rail Coal by Wire Coal to Gas by Pipeline Coal to Gas by Wire

Annual Cost ($millions

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Shipping Energy Conclusions

• If infrastructure exists (rail lines), then it is best to use it.

• For new investment, alternatives to rail can be attractive but involve trade-offs.

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Some Other Common Tools (Continued)

• Materials flow analysis• Appropriate boundary setting.• Risk and uncertainty analysis.• Life cycle cost analysis.

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What can be done to promote sustainability?

• Policy• Education• Research• Local Action• Personal Action

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Some Policy Examples

• Fuel economy requirements and incentives – 25% cut in CO2 emissions proposed in EU.

• Higher density development and Brownfields re-development

• Toxics emissions and water use reporting and regulation.

• Full cost pricing: water, energy, …• Green buildings

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Sustainability Engineering Education Approaches

• Dedicated Engineering Courses: Two semester sequence for entry level grads or senior undergrads offered through CEE/EPP at Carnegie Mellon.

• Dedicated Non-Engr. Courses: “Environment and Technology” for undergraduate non-engineers.

• Modules: “Introduction to Environmental Engineering” introduces sustainability.

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Center for Sustainable Engineering

• Arizona State Univ. (Brad Allenby), Carnegie Mellon (Cliff Davidson) and U. Texas, Austin (David Allen) with EPA/NSF Funding

• Benchmarking of existing educational activity.• Development of educational materials• Workshops: 62 faculty & 40 schools at 2006

workshops in Pittsburgh; 7/07 workshops in Austin.

• Website and email list

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Some Research Examples

• Re-use and recycling of goods.• Alternative fuels and power generation.• Energy efficient buildings.• Carbon sequestration.• New Technology (bio-materials,

information technology, etc.)

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Switchgrass (Cellulosic) Ethanol

Distribution of Consumer

Preferences

Compact Car

Sports Car

Light TruckHydrogen

Gasoline

EthanolBiomass

Oil

Tar Sands

Plug-in Hybrid Electric

Internal Combustion

Fuel Cell

DistributionPipelines

Manufacturing Use End of Life

Rail Shipping

ProcessingResource Use Transportation

Coal Electricity

Vehicles ConsumersEnginesFuelsResources

Infrastructure& Policy

Decisions in the Marketplace

Impact:Life Cycle Analysis

Policy

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Wairakei Geothermal Plant, New Zealand

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Local Action: Carnegie Mellon

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Some Carnegie Mellon Projects (cont)

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Personal Action

• A wide range of possible responses, including self-sufficient farms.

• Some (relatively) easy actions:– Walk, bike, or ride, don’t drive.– Forgo more material possessions.– Support sustainable policies.

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What is slowing sustainability?

• Ignorance of methods and the implications of our actions: e.g. climate change debate, ecosystem limits.

• Reaction time: political and social changes slower than technology or economy.

• Difficult trade-offs among competing interests: e.g. wind power nimby

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Conclusions

• Promoting sustainable engineering is not really startlingly new, but does require some new perspectives.

• Triple bottom line assessment: economic, environmental, social

• Life cycle perspective essential• Challenges should not lead to paralysis.

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Some Resources• Center for Sustainable Engineering (ASU,

Carnegie Mellon, Texas): http://www.csengin.org/

• Carnegie Mellon Green Design Institute: www.gdi.ce.cmu.edu

• Input-Output Life Cycle Assessment: website at www.eiolca.net. Book: Environmental Life Cycle Assessment of Goods & Services: An Input-Output Approach, 2006. (RFF Discount Code: EGX)