Announcements and Reminders Exam #1

– For new grade: add +3 points, then calculate score out of 88 points total.– NOTE: Additional curve possible based on Exam #2 performance.

Friday, March 5– Pre-Activity 8.3.3 (Low-Flow)

Monday, March 8– DUE: Post-Activity and Bonus Turn-in 8.1.1– DUE: Pre-Activity 9.1.1 (complete prior to class)– Homework #3 Released

Wednesday, March 10– DUE: Project #2 Posters and Presentations

Friday, March 12– DUE: Project #2 Executive Summary– NO CLASS!

Learning Objectives

Be able to define sustainability, including in social, environmental, and economic terms, and through the use of relevant examples.

Understand how sustainable design principles and concepts are related to systems thinking.

Be able to define basic principles of cradle to cradle design.

Be able to define concepts of energy efficiency, payback, and footprint.

Be able to perform simple payback calculations.

Be able to perform basic footprint calculations.

Case Study #2: Interface Carpet As you watch the video, can you identify how it relates to the

social, economic, and environmental aspects of sustainability?

http://www.ted.com/talks/ray_anderson_on_the_business_logic_of_sustainability.html

“When we try to pick out anything by itself, we find it hitched to everything else in the universe.”

- John Muir

“When we try to pick out anything by itself, we find it hitched to everything else in the universe.”

- John Muir

Sustainability and Systems Thinking

Remember: A focus on relationships rather than individual parts. This can include technology, social aspects, environmental and economic impacts.

Source: McDonough and Braungart, 2006

Cradle to Cradle Design“[M]oving from the lean production of potentially degenerative technology to the clean production of potentially regenerative technology.”

“A framework in which the safe regenerative productivity of nature provides models for wholly positive human designs. Working from this perspective, we do not aim to be less bad. Instead, our design assignment is to create a world of interdependent natural and human systems powered by the sun in which safe, healthful materials flow in regenerative cycles, elegantly and equitably deployed for the benefit of all.”

- McDonough and Braungart, 2006

Cradle to Cradle Design

• Products and processes that minimize harm to people and environment WHILE enhancing people’s health and regenerate environment

• Products that when their useful life is over, do not become useless waste but become nutritious food for plants and animals or renewable high-quality materials for new products

• Buildings that produce more energy than they consume and purify their own waste water

• Transportation that improves the quality of life while delivering goods and services

• Add environmentally or socially beneficial features to traditional design

William McDonough and Michael Braungart (2002)

Sustainability: Tools and Concepts Energy Efficiency

Payback

Environmental Impacts

– Ecological footprint

– Water footprint

– Carbon footprint

Image Source: http://icanhascheezburger.files.wordpress.com/2009/01/funny-pictures-bear-will-eliminate-your-carbon-footprint.jpg

Energy Efficiency

Energy efficiency is the quality of being able to do a task successfully without wasting energy.

Example: More Energy-Efficient Water Heating• Reduce your hot water use • Lower water heating temperature• Insulate your water heater tank• Insulate hot water pipes• Install heat traps on a water heater take• Install a timer and use off-peak power for an electric water heater• Install a drain-water heat recovery system• Install a more energy efficient water heater

http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=13030

Water Heaters: Efficiency and Costs

http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=13000

Simple Payback for Water Heaters Simple Payback (SPB) - The amount of time it will take to cover the

initial installation cost given the total cost savings of the measure.

Examples:– Replace a functional convectional gas storage (EF=.6) water heater with an on-

demand gas water heater (EF=.8)

– Replace a functional convectional gas storage water heater (EF=.6) with an on demand gas water heater (EF=2.2)

€

Measure Cost

Cost Savings= Simple Payback

€

SPB =$1600

$350 / yr −$262 / yr=18 years

€

SPB =$1660

$350 / yr −$190 / yr=10.4 years

Simple Payback for Light Bulbs

Image Source: http://aeftraining.com/images/resize_of_adaptor_on_right_w-t-5_5iq2.jpg

Changing lights from T-12 light bulbs to T-8 light bulbs is a common energy and cost saving measure in commercial buildings.

A 4 lamp T-12 fixture (180 Watts) can be replaced with a 3 lamp T-12 fixture (88 Watts) for about $67.50. If the lamps are on 12 hours a day, 275 days a year at a cost of 9.5 ¢ / kWh, what is the simple payback?

Cost of the T12

Cost of the T8

Simple Payback

€

12hrs

day×275days

yr×$0.095

kWh×kWh

1000Wh×180W = $56.43/ yr

€

12hrs

day×275days

yr×$0.095

kWh×kWh

1000Wh× 88W = $27.59/ yr

€

SPB =$67.50

$56.43/ yr − $27.59/ yr= 2.3 years

Energy Savings Model for Light Bulbs

4-lamp T12 magnetic retrofitted to 4-lamp T8 electronicNote: Blue cells are variables that can be changed

Duty cycle (hrs/day): 12

Days/year: 275Energy cost per

KWH: 0.095

  3-lampSystem: 4-lamp Full output

Magnetic T12 Electronic T8Retrofit Cost:

Ballast cost:   20.00Lamp cost:   7.50Labor cost:   40.00

Available rebate:    Total cost:   67.50

Operating cost/yr/fixture:Average Watts/fixture/hour: 180 88Average KWH/fixture/year: 594.00 290.40

Energy cost/fixture/year: 56.43 27.59Annual energy savings:   28.84

Time to recover install cost in years:   2.34   

Five year energy savings:   144.21Five year energy savings less install cost:   76.71

Note: All figures are per fixture.

Axis ballast wattage is based on estimated average per fixture.

Ballast cost, lamp cost, and labor are estimated

Input variables: the hrs/day, days/year, energy cost, and lamp and labor cost can be changed.

Any available rebate can be entered as a negative number-this greatly shortens the Axis payback period.

Note that the time to recover install cost (without a rebate) is nearly the same for the standard T8 vs the Axis dimming T8.

After the payback period, however, the Axis ballast saves a much greater amount of energy dollars.

http://www.youtube.com/watch?v=6Eg_SEAnE-M

Environmental Impacts: Footprints Ecological footprint – total amount of

land and sea needed to provide all resources for, and absorb all wastes of, a given human population.

Water footprint – total amount of water consumed by a person or organization per unit of time.

Carbon footprint - amount of greenhouse gases emitted by a person, organization, process per unit of time. Likely represents ~50% of humanity’s total ecological footprint.

http://impresssions.org/yahoo_site_admin/assets/images/The_Human_Footprint.229135752_std.jpg

Source: http://www.soe.wa.gov.au/site/files/images/Figure-FP1.2_Large.jpg

Source: http://www.footprintnetwork.org/en/index.php/GFN/page/carbon_footprint/

Water Footprint Example Compare the water footprint of the following fuels by calculating gallons

of water consumed per 100 miles driven.

Source: http://er100200.berkeley.edu/problem_sets/PS6_09.pdf

Water Footprint Example

Regular gasoline

Corn Ethanol€

100 miles×1 gallon of gasoline

25 mile×2 gallons of water

1 gallon of gasoline= 8 gallons of water

€

100 miles×1 gallon of corn ethanol

17.5 miles×1000 liters of water

1 liter of corn ethanol× = 5714 gallons of water

Carbon Footprint Example Indiana’s average emissions are 0.271 kg of carbon emissions

per kWh1. Calculate the Carbon foot print of a 4 lamp T-12 fixture (180 Watts) which runs 12 hours a day, 275 days a year?

1 http://www.purdue.edu/climate/pdf/CN@P_FINAL.pdf

€

12hrs

day×275days

yr×kWh

1000Wh×180W ×

0.271kg

kWh=161kg of Carbon