Studying and Learning from Our Own Energy Use
ACI Home Performance Conference 2011
Jackie Berger, Su Wang, Chisoo Kim
Parfait Gasana, Ferit Ucar
April 1, 2011
APPRISE
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• Nonprofit research institute• Mission: Analyze data and information to assess and
improve public programs• Research areas: Energy efficiency and energy
affordability• Clients
– Federal government (DOE, HHS)– State governments– Utility companies– Nonprofits
Staff Activity
• Monthly lunch and learns
• Pick one aspect of home energy usage to target for reduction
• Take this action for one month
• Report on findings
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Reporting
• Which behavior did you decide to change and why?
• How did you do?
• What challenges did you face?
• What impact do you think this had on your energy usage and why?
• Estimate the kWh or ccf or $ impact?
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Insights
• Energy program implementation
• Energy education
• Energy usage behavior change
• Energy program evaluation
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Personal Energy Saving Effort: Challenges and Lessons
Su Wang
ACI Home Performance Conference
April 1, 2011
Home Overview
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Home Overview
• Home Type: studio w/balcony• Utilities: gas heat & hot water, coin laundry• Entertainment: no TVs, no audio systems• Appliances: 1 dorm-size refrigerator• Lighting: Fluorescent, CFL, or LED lights• Energy Use: 1,290 kWh for past 12 months
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Goal
• Reduce Laptop Energy Use • Why Important:
Behavior would have monetary impact Improve health and wellbeing
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2009 MethodSept-Oct 2009:• Turn off computer and unplug power strip when
leave for more than 1 hour• Manually put computer on standby mode when
leave for more than 15 minutes
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2009 Challenges
Turning Off:• Couldn’t tell when leaving for 1+ hour• Takes awhile for computer to turn on• Rush to catch buses/subways, no time to
turn offStandby:
• Couldn’t tell when leaving for 15+ minutes
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2009 Performance
Turning Off:• Did not turn on computer in the morning for
short periods of use• Unplugged every night after turning off, but
I was doing that already!Standby:• Set computer to go to automatic standby
after 15 minutes, but it was already on that setting!
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2009 Impacts - Usage
• Effort started right after cooling season
• Changed all light bulbs to CFLs just before
• Electric meter room locked
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2009 Impacts – Electric Usage
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2010 MethodDec-Jan 2010/11:• Reduce Computer Usage Time:
Maximum of 1 hour per day on weekdays Maximum of 2 hours per day on weekends
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2010 Challenges• Weather in NY/NJ in Dec/Jan• Wedding photos received in mid-Dec• Graduate candidacy exam• New York Public Library reserve system• Lack of inexpensive entertainment• After breaking rules a few times, just gave up…
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2010 PerformanceWeekdays:
• Followed schedule for a week and a half…
• Gave up and used normal amount of 1-2 hours per day
Weekends:
• Followed schedule for 1 weekend – busy with library books to read…
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2010 Impacts - Usage
• Only followed plan for about 1.5 weeks
• Replaced humidifier use with bowl of water
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2010 Theoretical Impact
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Time Old Hours
New Hours
Hours Saved
Laptop Use/Hr
Savings
Weekdays
10 5 5 0.09 kWh 0.45 kWh
Weekends
8 4 4 0.09 kWh 0.36 kWh
1 Week 18 9 9 0.09kWh 0.81 kWh
1 Year 936 468 468 0.09kWh 42.12 kWh42.12kWh x $0.18-$0.39 = $7.59-$16.43
Conclusion: not worth it!
Kill-A-Watt Metering:My Laptop: 0.03kWh per hourHusband’s Laptop: 0.06kWh per hour
Electric Savings from Humidifier
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Humidifier Impacts
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Humidifier Impacts
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Month 2009-2010 2010-2011 Change
October 79 kWh 68 kWh 11 kWh
November 97 kWh 54 kWh 43 kWh
December 96 kWh 79 kWh 17 kWh
January 90 kWh 79 kWh 11 kWh
February 89 kWh 78 kWh 11 kWh
Average 88.50 kWh 76.00 kWh 12.50 kWh
Humidifier Impacts
• 12.5 kWh x 7 months (Oct-Apr) = 87.5 kWh• Verification (Kill-A-Watt metering):
0.35 kWh x 30 days = 10.5 kWh 10.5 kWh x 7 months = 73.5 kWh
• No definite dollar value available Changing rates Regulated utility => ESCO w/100% wind power 87.5kWh x $0.18-$0.39 = $15.75-$34.13
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Lessons
• Alternative needed when attempting lifestyle change
• One-time changes easier to make than actions requiring continued effort
• Weather can have a big impact not just on heating/cooling
• Program evaluation – energy saving potential can differ in homes; important to benchmark
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Personal Energy Saving Effort: Challenges and Lessons
Chisoo Kim
ACI Home Performance Conference
March 2011
PART 1: VAMPIRE USAGE
Home Overview
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Home 1 Home 2
Home Overview
• Home 1: – 3rd floor loft apartment– Heating: Forced air– Cooling: Central A/C with a ceiling fan– Programmable thermostat– Most of lights are CFLs– Monthly Electric Usage: 4,045 kWH– Monthly Gas Usage: 198 Thm
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Home Overview
• Home 2: – Single family detached– Heating: Gas heat, zoned– Cooling: Central A/C– 2 programmable thermostats– Hot tub– Annual Electric Usage: 15,147 kWh– Annual Gas Usage: 1,217 Thm
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Goal
Reduce vampire energy usage from entertainment units.
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Why important?
• Vampire usage has no purpose• Wouldn’t cause significant inconvenience• On a national basis, vampire power
accounts for more than 100 billion kwh of annual U.S. electricity consumption (Source: www.energystar.gov)
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Energy Saving Behavior:Saving Energy for Entertainment Units
• Method 1: Turn off the entertainment units• Method 2: Use smart strip for the
entertainment units• Method 3: Turn off the switched-outlet
with entertainment units when not in use
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Challenges
• Inconvenience: Turning a cable box resets it.
• Not all the houses have switched outlet you can turn off.
• Is there a financial incentive to invest in a smart strip? (smart strip costs $25-$35)
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Performance
• Forget to turn off power strip
• Smart strip: Once installed, didn’t have to remember to turn it off.
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Impacts – Usage
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DVD player 0 wh
VCR 0 wh
Wii 0.1 wh
Total 0.1wh × 20 hrs × 365 days = 0.73 kwh/yr
Smart Strip
DVD player 0 wh
TV 20 wh
Cable box 30 wh
Total 50 wh × 12 hrs × 365 days = 219 kwh/yr
Power Outlet
Impacts – Dollar Savings
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Power outlet
219 kwh/yr × $0.18/kwh = $39.42/yr
Smart Strip
0.73 kwh/yr × $0.18/kwh = $0.13/yr
Lessons
• Make it easier to follow-through– Install one time measure– Or incorporate the energy-saving measure in
routine
• Need to take benchmark before installing energy-saving measure
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PART 2: WATER USAGE
Home Overview
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Home Overview
• Three room apartment• One full-size bathroom• One TV, no audio systems• Full-size refrigerator• Gas heat, central handler • Annual Electric Usage: 4,200kWh• Annual Gas Usage: 1,080 Thm
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Goal: Reduce Water Use in the Bathroom
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Why Important
• Consistent behavior might have monetary impact
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Method• Turn off water when lathering• Use low-flow showerhead
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Challenges
• Decrease in comfort– Turning off hot water in the winter was too
uncomfortable
• Lack of motivation– Did not seem worth it relative to average length of
shower (4.5 minutes)
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Performance
• Did not turn off water while showering– Winter was too cold, too uncomfortable
• Unable to replace showerhead with low-flow showerhead
• Took many showers in the gym
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Impacts - Water Usage
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HOUSEHOLD (3 PEOPLE)
4.5 min+15 min+20 min=39.5 min
Before 5gpm
× 39.5 min =
197.5gal/shower
After 2.5gpm 98.8 gal/shower
Savings 2.5 gpm 98.8 gal/shower
INDIVIDUAL
4.5 min
Before 5gpm
× 4.5 min =
22.5gal/shower
After 2.5gpm 11.3 gal/shower
Savings 2.5 gpm 11.3 gal/shower 78.8 gal/week
691.3 gal/week
Impacts – Dollar Savings
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• Savings are only from water usage. Savings from hot water usage is larger.
$ Savings of water/week
INDIVIDUAL 78.8gal/week× $0.007/gal =
$0.56
HOUSEHOLD 691.3 gal/week $4.84
Lessons
• Willingness to change behavior (sacrifice)• Choose changes that only need to be made once
(i.e., installation of low-flow showerhead) over habitual changes
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Personal Energy Saving Effort: Challenges and Lessons
Parfait Gasana
ACI Home Performance Conference
April 1, 2011
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Home Overview• Type: Single-family detached rental, 2 stories, 4
bedrooms, 1 bathroom –about 1,500 sq ft.• Occupants: 3 (1 professional, 2 college students)• Heating: force-air gas system/dual central ac with
programmable thermostats• Appliances: gas stove, refrigerator, electric water
heater, clothes washer and gas dryer• Electronics: living room set with large audio system, LCD
TV, Xbox and Wii, router, satellite box
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Electric Usage
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Month kWh
June 2010 234
July 2010 313
August 2010 452
September 2010 696
October 2010 500
November 2010 601
December 2010 594
January 2011 866
February 2011 625
Total 9 months 4,881.3
Total 12 months 6,508.4*June-Aug. are estimated readings
Energy Opportunities
• Better use of programmable thermostat
• Smart strip for entertainment center
• Reduce appliance use (weekly oven use, necessary clothes washing)
• Non-behavioral (tuning forced air system, thermal blanket, downstairs insulation)
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Energy Saving Behavior
• Goal: Reduce hot water usage• Why Important:
1. Water heating accounts for 14-25% of household energy consumption (Dept. of Energy).
2. Involves many domestic activities.
• Method: Use cooler water in showering, cleaning, washing dishes, and clothes.
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Challenges• Uncomfortably cold during winter
• Issue of germs and bacteria with cooler water
• Household members lack of participation
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Performance
• Good effort but tough to commit on regular basis
• Certain activities easier than others• Recurring behavior habit
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Impacts - Usage• Water heating depends on various factors
(water temp., flow rate, and time)• Heat energy equation:
– Q = cpmΔT → Q = [(1btu/lb º F)(x lbs)(Tf – T0)]
• Unit of Measurement:– BTU - energy required to raise 1lb. of water by 1 degree Fahrenheit
To shower 15 min. w/o lukewarm water:o [37.5 gal*8.3 lbs/gal(104º -50º)] btus = 16807.5btus = 4.92 kWh
To shower 15 min. w/ lukewarm water:o [37.5 gal*8.3 lbs/gal(85º -50º)] btus = 10893.75btus = 3.19 kWh
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Impacts – Dollar Savings
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Water Heating EffortPre-temp
Post-temp
Savings Per Use
Savings Per Day
Savings Per Month
Showering (BTU) 16.8 10.9 5.9 5.9 177.4 (kWh) 4.9 3.2 1.7 1.7 51.9
Dollars $0.88 $0.57 $0.31 $0.31 $9.29Washing dishes (BTU) 9.0 5.8 3.2 3.2 94.6
(kWh) 2.6 1.7 0.9 0.9 27.9Dollars $0.47 $0.30 $0.17 $0.17 $4.99
Clothes washing (BTU) 7.8 0.0 7.8 0.8 23.5(kWh) 2.3 0 2.3 0.2 6.9
Dollars $0.41 $0.00 $0.41 $0.04 $1.24Total Dollar Savings $0.52 $15.52*BTUs are measured in thousands*kWh/dollar = $0.179*Water was not heated for post temp clothes washing
Lessons• Benchmark: benefit outweigh cost?
• Targeted focus over many activities and varying preferences
• All household member participation
• Needed log and instrument for precise estimates
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Personal Energy Saving Effort: Challenges and Lessons
Ferit Ucar
ACI Home Performance Conference
April 1, 2011
Home Overview
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Home Overview
• Three-level townhome in an apartment community• 1,300 Sq. Ft., Built in 2005• Central air heating and cooling, single zone• Thermostat on 2nd floor, Gas furnace on 3rd • All lights are CFLs• New Appliances• Annual Electric Usage: 3,400 kWh• Annual Gas Usage: 550 ccf
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Energy Saving Behavior
• Goal: Reduce gas usage for heating• Method: Turn down the thermostat
– Day: 70 68 Night and Out: 70 65
• Why important?– Biggest energy saving opportunity– Take advantage of temperature difference between
floors– Reason to watch less TV
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Challenges
• Setting/resetting the thermostat on a regular basis• Downstairs sometimes felt uncomfortable • Closing/opening upstairs vents • Cold mornings • Wife prefers it warmer• Having guests over
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Performance
• Good performance with small deviations• Thermostat settings• Upstairs vents• Longer showers• TV and lights
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Impacts-Gas Usage
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Jan 2010 Jan 2011 % Change
Therms 121 130 +7%
HDD 1,022 1,154 +13%
Therms (Weather-normalized) 121 117 -3%
Feb 2010 Feb 2011 % Change
Therms 109 116 +6%
HDD 999 1,097 +10%
Therms (Weather-normalized) 109 107 -2%
Impacts- Dollar Savings• In the absence of behavior change, my gas usage would
have been 6 therms higher over two months
(130*0.8*4%+116*0.8*2% ≈ 6 therms)
• Potential Savings on Heating Bill: 4% over Winter
4%*[(130*0.8/1,154)*5,000] ≈ 18 therms
• I saved: 6*$1.30=$8 (over 2 months)
• I could potentially save: 18*$1.30=$23 (over Winter)
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Impacts-Electric Usage
• Electricity usage ↓ by 10% in Month 1Watched less TV and used less electricity for
lighting.
• Electricity usage ↑ by 25% in Month 2Watched less TV and used less electricity for
lighting. BUTMore washing, drying, ironing, and vacuumingFriends over for the weekendUse of a humidifier and an electric kettle
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Lessons• The need for programmable thermostats
• Split incentive problem in rental housing
• Importance of behavior change
Program Evaluation:
• Target homes with higher pre-usage (savings potential)
• Individual HH might not see the effect. Average over many homes and use of comparison group can document savings due to a usage reduction program.
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