(390133572) 226670204-sustainable-engineering-2.docx

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SUSTAINABLE ENGINEERING

What it is, How to do itand How to measure it

Benoit Cushman-Roisin

ENGS-21

7 November 2008

When we see these things,

dontwe need to rethink engineering?

Problems are all around us,on land, in water and in the air.And those are only the visible ones


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Engineering has spurred and led the industrial revolution. But, inthe process it has created important classes of problems, including:

Human exposure to toxics in food, air, water and soil

Rising demand for energy for transport, manufacturing,heating & cooling

Depletion of non-renewable resources (petroleum, metals)

Excessive demand for water for consumption, agriculture, industry

Rising demand for land for housing, food production,economic activities (production, retail, transportation)

Ever increasing number and size of landfills

Ecosystem damage and habitat loss due to pollutant discharges Impact on global climate

and the litanygoes on.


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Definition of Environmental Technology

(according to Bridge to a Sustainable Future, Clinton White House, April 1995)

An environmental technology is a technology that

- reduces human and ecological risks (better for us and nature, during production),

- enhances cost effectiveness (more for less money) ,

- improves process efficiency (more with less material and less energy) , and

- creates products and processes that are environmentally beneficial or benign(better for us and nature, during use).


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There is currently no accepted definition of Sustainable Engineering,

but the concept may be encapsulated as follows:

Engineering in context

Engineering with a conscience

Engineering for a finite planet and the indefinite future(and no the other way round!)

In our every deliberation we must consider the impact of our decisions on thenext seven generationsfrom the Great Law of the Iroquois Confederacy andused as lead inspiration by the Seventh Generation Company.

Three main challenges:

1. What are the main principles of Sustainable Engineeringand how can they be applied to solve the problems?

2. Where should the boundaries lie? Boundaries are critical becausethe wrong scale can hide critical links.

Ex: switching from steel to lightweight composite in an automobilecan boost fuel efficiency but break the recycling system.

So, it would seem that the wider the better, but how wide?

3. How can Sustainable Engineering be taught to the next generationof engineers? Modules in existing courses? New courses?New curriculum?


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(http://www.fhwa.dot.gov/eihd/navajo.htm)

Traditional Engineering:

Considers the object

Focuses on technical issues

Solves the immediate problem (now)

Considers the local context (user)

Assumes others will deal withpolitics, ethics & societal issues

Sustainable Engineering:

Considers the system in whichthe object will be used

Integrates technical and non-technical issues

Strives to solve the prob lem forthe indefinite future

Considers the global context(planet)

Acknowledges the need forengineers to interact with experts

in other disciplines related to theproblem

A few examples of Sustainable Engineering (SE):

The Navajo Bridge in Arizona:

Simple bridge across Marble Canyon but fierce opposition from localnative tribe and Bureau of Land Management

Solution:

- Talk with all entities involvedbefore designing anything

- Design with these constraintsin mind: respect for land,functionality, long term,aesthetics, etc.

The new Navajo Bridge in Grand Canyon National Park is the only crossing of the Colorado Riverfor a stretch of 600 miles. The $15 million steel arch bridge carries traffic across Marble Canyon,470 feet above the Colorado River. The 1929 Navajo Bridge remains a pedestrian bridge. Highstrength steel was used in the new bridge in order to be visually compatible with the historic bridgeand its setting.
http://www.fhwa.dot.gov/eihd/navajo.htm


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Designing a new computer infrastructure:

- Traditional engineering:

Focus on performance

- Sustainable Engineering:

How will widespread useimpact electricity demand

and electronics recycling?

(https://reader010.{domain}/reader010/html5/0608/5b1a1fdd43877/5b1a1fe12e4fd.jpg)

Designing a new arsenic-based wood preservative:

- Traditional engineering:

How effective is it in my wood product?

- Sustainable Engineering:

How will wide use affect theconstruction industry?

How will the chemical affect

demolition waste/recycling?

(Photo: Beauchemin Lumber)
http://www.cs.cmu.edu/pics/campus/images/servers.jpghttp://www.cs.cmu.edu/pics/campus/images/servers.jpg


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Traditional engineering:

How can I make a tire that betterresists sand abrasion and heat?

Sustainable Engineering:

Where will all the rubber for thiscome from?

Where will all these tires goat the end of their useful life?

Some tools are already available:

- Eco-Industrial Parks (EIPs)

- Pollution Prevention (P2)

- Design for Environment (DfE)

- Life-cycle Assessment (LCA)

- Leadership in Energy & Environmental Design (LEED)

and more tools could be developed:

- Total Cost Accounting

- Sustainability Indicators


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Eco-Industrial Parks:

Basic idea: Mimic nature by gathering industrial activities in one location topromote interactions and close-loop practices, like in natural ecosystems.

Systemsthinkingrequired !

Flow resources in theintegrated biosystemof Montford BoysTown in Suva, Fiji

Pollution Prevention:

Basic idea: Avoid waste pollution in the first place, as much as possible

3P at 3MPollution Prevention Pays,since 1975


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Example from 3M: The manufacture of Scotch tape

primeradhesive plastic film

primerbacking

4 layers, each using a solvent for its application !

One of 3Msprimary strategies for continuing to reduce air emissions has been thedevelopment of solventless technologies, for a variety of products including tapes.

Some new processes are hot-melt technology, ultraviolet curing and caustic washmaterials.

Design for Environment:

Basic idea: Include environmental considerations at the very beginning of

the design process, together with performance, manufacturability, cost andsafety.

Considerations:

- Less material- Less material variety- Recycled materials- Recyclable materials- Ease of disassembly- Less energy consumption- Longevity- Modularity

etc.


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Life-Cycle Assessment (LCA):

Basic idea: Consider the entire productcycle from cradle to grave (procurementof raw materials, manufacture,distribution, use and disposal)

Leadership in Energy & Environmental Design (LEED):

Basic idea: Guidelines to build green buildings

The Leadership in Energy and EnvironmentalDesign (LEED) Green Building Rating Systemisthe nationally accepted benchmark for the design,construction, and operation of high performancegreen buildings.

Rendering of new Life Sciences Centerat Dartmouth College

LEED gives building owners and operators the toolsthey need to have an immediate and measurableimpact on their buildingsperformance.

LEED promotes a whole-building approach to sustainability by recognizingperformance in five key areas of human and environmental health: sustainable sitedevelopment, water savings, energy efficiency, materials selection, and indoorenvironmental quality.

LEED provides a roadmap for measuring and documenting success for every buildingtype and phase of a building lifecycle.


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Well, that was all about HOW to design and build stuff.

But, WHAT should we actually build?What should be our priorities?

To start answering this last question, let us consider where thebiggest impacts are. A good place to start is energy consumption.

Indeed, energy consumption is related to many environmentalproblems, some upstream (depletion of non-renewable energysources & oil spills) and some downstream (air pollution andgreenhouse gases).

Energy consumption thus serves as a good proxy for overall

environmental impact.

A look at how we

consume energy in the

United States is quite

telling.

Two things stand out:

- Heating, ventilationand air conditioning ofbuildings

- Road transportation.

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A regenerative building?

Want to know more about this?Take ENGS-44 Sustainable Design

A green vehicle? One answer: Fuel-cell engineswith a hydrogen economy

(http://www.fair-pr.com/meet-aae/grove2005/exhibition.php)

Want to know more about this? Take ENGS-171 Industrial Ecology
http://www.fair-pr.com/meet-aae/grove2005/exhibition.phphttp://www.fair-pr.com/meet-aae/grove2005/exhibition.php


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Measuring theenvironmental impactsof your designs:

A basic life-cycle approach

Charts of Okala millipoints


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An application exampleof the Okala method:

Button vs. Zipper?

So, which one is better for the environment?


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A closing thought:

Engineering is not just an activity, it is a profession.

A profession rises above an occupational specialty by including both

- The cultivation of specialized knowledge, and

- The use of that knowledge toward the Common Good.

(Daniel R. Lynch, 2006)

Reminder: Thayer School exists

to prepare the most capable and faithful for themost responsible positions and the most difficultservice. Sylvanus Thayer

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