NC State University Intersession Energy Savings

Initiative 2010-2011

Intersession Energy Savings InitiativeOverview

• Project Description- NC State closed on Thursday, December 23, 2010 and

reopened on Monday, January 3, 2011 for Winter Break. During this time, Facilities Operations, and others, set back building temperature set points that do not cause building damage, such as freezing, while at the same time providing the maximum energy conservation. The setback temperatures are 55 to 60 degrees F. The setback program has been in effect since 2005.

• Business Case- By lowering building temperature set points, NC State can

save natural gas and electricity; thereby saving cost and lowering carbon emissions. Since 2004, the program has saved more than $1.2MM in avoided costs.

• Exception Process- The program has a formalized exception process that allows

certain buildings and building zones to remain at normal heat and humidity levels. This includes ongoing research buildings, occupied residences, and special needs (e.g., library collection standards).

• Setback Program Outreach- The campus community was informed about the program

through an email blast and routine media outlets. Instructions on shutting down non-essential lab equipment, closing fume hoods, shutting windows and doors, turning off lights and office equipment were communicated frequently.

• Project Leadership- Jack Colby, Assistant Vice-Chancellor for Facilities

Operations

• Project Facilitator- Utilities and Engineering, Energy Management

• Participating NC State Facilities Teams- Athletics

- Building Maintenance and Operations - Central Shops

- Campus Enterprise, Facilities Operations

- Carmichael Complex Facilities and Operations

- Dining and Catering Operation

- Housekeeping Services

- University Sustainability Office

- University Housing

- Utilities and Engineering, Central Plants

• Key Highlights for 2010- $187,238 Energy Costs Avoided

- 1,349 Metric Tons of CO2 Emissions Avoided (MTCO2)

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Intersession Energy Savings InitiativeCalendar

November 2010November 2010November 2010November 2010November 2010November 2010November 2010S M T W Th F S

1 2 3 4 5 6

7 8 9 10 11 12 13

14 15 16 17 18 19 20

21 22 23 24 25 26 27

28 29 30

December 2010December 2010December 2010December 2010December 2010December 2010December 2010S M T W Th F S

1 2 3 4

5 6 7 8 9 10 11

12 13 14 15 16 17 18

19 20 21 22 23 24 25

26 27 28 29 30 31

January 2011January 2011January 2011January 2011January 2011January 2011January 2011S M T W Th F S

1

2 3 4 5 6 7 8

9 10 11 12 13 14 15

16 17 18 19 20 21 22

23 24 25 26 27 28 29

30 31

• Thanksgiving Setback Period (Pilot)

- November 25 - November 28

- Thanksgiving Holiday included in Initiative for the first time in 2010

• Pre-Holiday Setback Period (Pilot)

- December 17 - December 23

- Pre-Holiday period included in Initiative for the first time in 2010

• Winter Holiday Setback Period

- December 24 - January 2

- Program in effect since 2005 with more than $1.2MM in avoided costs recorded

Thanksgiving

Pre-Holiday

Winter Holiday

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Intersession Energy Savings InitiativeParticipation and Targeted Buildings

• Affected Building Count Building Count Percentage

Targeted 24434.5%

Non-Targeted 23032.5%

Excluded 233 33.0%

Total 707100%

• Affected Square Footage Gross Square Footage Percentage

Targeted 11,854,95478.7%

Non-Targeted 1,152,5907.7%

Excluded 2,045,057 13.6%

Total 15,052,601100%

• Definitions- Targeted: Included in 2010 Intersession Initiative

- Non-Targeted: Excluded from 2010 Intersession Initiative

‣ Buildings occupied during holiday period

‣ Areas unable to be separately controlled

- Excluded: Always excluded from 2010 Intersession Initiative

‣ Critical Lab, Research and Veterinary Spaces

33.0%

32.5%

34.5%

13.6%

7.7%

78.7%

In Program

In Program

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Intersession Energy Savings InitiativeWinter Break Analysis: Dec 24 - Jan 3

5,000,000 GSF

7,500,000 GSF

10,000,000 GSF

12,500,000 GSF

15,000,000 GSF

2004 2005 2006 2007 2008 2009 2010

Campus Gross Square Footage• Growth of NC State’s Campus- NC State is growing at a healthy rate - in 2010

alone, more than 725,000 square feet were added to the campus. Along with this necessary growth, energy consumption naturally tends to grow at a similar rate. In order to compare energy use to prior years, energy consumption per gross square foot (GSF) is the accepted unit of measure.

• The Effects of Heating Degree Days- Heating Degree Days (HDD) are a method of

normalizing energy data for the effects of weather from one year to the next. The extreme weather in 2009 continued during the 2010 setback period, which required the University buildings to consume more energy to stay within a safe temperature range to avoid freezing building HVAC and plumbing systems.

- HDD are calculated by subtracting the average daily temperature from a baseline temperature of 65ºF. These values are added together for each intersession period. Colder temperatures during the setback period created a higher HDD value, and subsequently, required additional energy consumption to heat the campus buildings to a safe temperature range.

Bas

elin

e

0 HDD

80 HDD

160 HDD

240 HDD

320 HDD

2004 2005 2006 2007 2008 2009 2010

Setback Period Heating Degree Days

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Intersession Energy Savings InitiativeWinter Break Analysis: Dec 24 - Jan 3

3,000,000 kWh

3,750,000 kWh

4,500,000 kWh

5,250,000 kWh

6,000,000 kWh

2004 2005 2006 2007 2008 2009 2010

Campus Electric Energy Consumption

Normalized Electric Utility ConsumptionTrendline for Normalized ConsumptionActual Electric Utility Consumption

• Actual Electricity Consumption- 2004 is the baseline year, prior to the start of the

Intersession Energy Savings Initiative. Electric consumption expressed as kilowatt-hours (kWh), is not as weather dependent as natural gas consumption, but is affected by the growing campus.

• Normalized Electric Consumption- Since 2004, the campus has grown nearly 3MM

GSF and the number of HDD increased from the baseline by 14%. Normalizing energy use compared to a baseline allows a direct comparison between program years. In 2010, the normalized data shows a 29% decrease in electricity consumption compared to the baseline year, and a 2% improvement over last years’ program.

Bas

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Intersession Energy Savings InitiativeWinter Break Analysis: Dec 24 - Jan 3

10,000 MMBTU

17,500 MMBTU

25,000 MMBTU

32,500 MMBTU

40,000 MMBTU

2004 2005 2006 2007 2008 2009 2010

Campus Natural Gas Consumption (MMBTU)

Normalized Natural Gas ConsumptionTrend for Normalized NG ConsumptionActual Natural Gas Consumption

• Actual Natural Gas Consumption- 2004 is the baseline year, prior to the start of the

Intersession Energy Savings Initiative. Natural Gas consumption expressed as total British Thermal Units (BTU), is highly weather (temperature and humidity) dependent. It is also affected by the increased campus GSF since the baseline year.

• Normalized Natural Gas Consumption- Since 2004, the campus has grown nearly 3MM GSF

and the number of HDD increased from the baseline by 14%. Normalizing energy use compared to a baseline allows a direct comparison between program years. The normalized data shows a 27% decrease in natural gas consumption compared to the baseline, but a 13% increase over last year’s program.

- Further analysis is required, and Energy Management is analyzing historical plant data and enthalpy to fine-tune our results. Enthalpy is a measure of the embodied energy in the outside air, and adds relative humidity to the factors affecting energy use. It is expected that since enthalpy is calculated using temperature and relative humidity, it is a stronger normalization factor for energy consumption, both for natural gas and electric utilities.

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Intersession Energy Savings InitiativeWinter Break Analysis: Dec 24 - Jan 3

$0

$75,000

$150,000

$225,000

$300,000

2004 2005 2006 2007 2008 2009 2010

$54,563$74,077

$129,802

$98,379

$118,289

$64,351

$0

$132,675$117,102$126,212

$113,343$122,489

$71,174

$0

Energy Cost Avoidance to Base Year

Electric Utility Cost AvoidanceNatural Gas Utility Cost Avoidance

• Energy Cost Avoidance- By comparing the normalized energy

consumption to the 2004 baseline year and adding the utility rate (cost) component, values of actual dollars saved are calculated.

- Using this approach, more than $1.2MM in utility costs have been avoided since 2004. The chart below shows the yearly totals and cumulative savings.

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2005

2006

2007

2008

2009

2010

$0

$375

,000

$750

,000

$1,1

25,0

00

$1,5

00,0

00

$187,238

$191,179

$256,014

$211,722

$240,778

$135,525

$1,2

22,4

55

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Intersession Energy Savings InitiativeWinter Break Analysis: Dec 24 - Jan 3

0

375

750

1,125

1,500

2004 2005 2006 2007 2008 2009 2010

516676

404

306

368

227

0

833793855

768914

539

0

Carbon Dioxide Avoidance to Base Year (MTCO2)

MTCO2 from Electric Utility ConsumptionMTCO2 from Natural Gas Utility Consumption

• Since 2005, nearly 7,200 MTCO2 of carbon emissions have been avoided.

• Avoided MTCO2 equates to more than 1,700 passenger vehicles off the road (US EPA estimates).

• Sources:- Natural Gas: US Inventory of

GHG Emissions and Sinks 1990-2008 (April 2010).

- Electric: US EPA eGRID2007 Version 1.1.

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• Key Highlights- Avoided Energy Costs

• $187,238 avoided in 2010

• $1,222,455 avoided since 2005

• Lessons Learned- There was some confusion during the exception submission

process - many of the requests were from “Excluded” buildings. In the future, Energy Management will design the exception request website to be more intuitive and easier to understand, clearly identifying the excluded buildings.

- The announcement to Campus was deployed late this year, and likely contributed to the amount of exception requests that were received after the published deadline. All of the late exceptions were reviewed and responses were provided. However, in future programs, care will be taken to provide adequate clear and concise information with sufficient notice so that the campus community will have time to respond and prepare for the Energy Savings Initiative.

- During the analysis of energy savings, Energy Management determined that previous years’ analyses had not fully considered campus growth in the evaluation. A full rework of the analysis template was created and fully considered campus growth, utility rate increases and carbon emissions avoided. The new template is set up for simple yearly updates and comparisons.

- Avoided CO2 Emissions

• 1,349 metric tons avoided (MTCO2) in 2010

• 7,199 metric tons avoided since 2005

• Opportunities for 2011- Energy Management has projected that energy consumption

by the Central Utility Plants (CUPs) is dependent upon temperature and relative humidity. In our region, temperature and humidity fluctuate significantly during a typical day. In future Intersession programs, hourly climate data will be analyzed in conjunction with the CUPs energy consumption and steam and chilled water production.

- The 2010 Intersession Energy Savings Initiative announcements and exception request system will begin earlier to allow more preparation by Energy Management, BM&O, faculty, staff and students.

Intersession Energy Savings InitiativeLessons Learned and Projections for 2011

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Intersession Energy Savings InitiativePilot Program Expansion: Nov 25 - 28 and Dec 17 - 23

• Project Description- In a partnership between Energy Management and Building

Maintenance and Operations, a pilot program expanding energy setbacks was implemented for the first time. During Thursday and Friday of the Thanksgiving holiday, and during the week before the Winter “deep freeze”, buildings were minimally set back to the weekend schedule, and where possible, more aggressive setbacks were implemented.

• Business Case- Lowering the building temperatures to “unoccupied” status during the

the additional days prior to the Winter University Closing did not incur significant cost to deploy. Any utility savings during this period were direct savings to the University Utility Budget.

• Limited Setback Program Outreach- Due to the nature of the expanded setbacks, very little outreach was

required. Wherever possible, buildings were set to typical weekend schedule, and in most cases, occupants were able to override setpoints to provide thermal comfort within their individual work spaces.

• Project Leadership- Jack Colby, Assistant Vice-Chancellor

for Facilities Operations

• Project Facilitator- Utilities and Engineering, Energy

Management

• Participating NC State Facilities Teams- Building Maintenance and Operations -

Central Shops

- Utilities and Engineering, Central Plants

• Key Highlights- More than $8,500 Energy Costs

Avoided during Thanksgiving Period

- More than $8,300 Energy Costs Avoided during week before Winter Shutdown

- ≈100 Metric Tons of CO2 Emissions Avoided (MTCO2)

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Intersession Energy Savings InitiativeThanksgiving Break Pilot Analysis: Nov 25 - Nov 28

All Campus 2009All Campus 2010Normalized All Campus 2010

20,000 kWh

22,500 kWh

25,000 kWh

27,500 kWh

30,000 kWh

Thur

sday

1:0

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M

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7:0

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Campus Electric Load Profile (PEC Load Profiler)

Thursday Friday Saturday Sunday

What Happened on Friday?During the period between Thursday evening and Saturday morning, when campus was in a “weekend” schedule mode, energy consumption increased. This unknown “event” has initiated an investigation within Energy Management to determine the root cause of the electric utility spike. 12

Intersession Energy Savings InitiativeThanksgiving Break Pilot Analysis: Nov 25 - Nov 28

-$250.00

-$125.00

$0

$125.00

$250.00

$375.00

Thur

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2009 v. 2010: Avoided Electric Utility Costs - Hourly

Thursday Friday Saturday Sunday

-$1,186

$1,987 $3,043 $4,775

Utility Costs AvoidedThe 4-day electric utility consumption dropped when comparing Thanksgiving Break 2010 to 2009. The increased consumption during Thursday night and Friday offset what would have been even greater savings. Even when taking this into consideration, more than $8,600 in avoided costs were realized. 13

Intersession Energy Savings InitiativePre-Holiday Pilot Analysis: Dec 17 - Dec 23

All Campus 2009All Campus 2010Normalized All Campus 2010

20,000 kWh

22,500 kWh

25,000 kWh

27,500 kWh

30,000 kWh

Frid

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2:00

AM

Frid

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Frid

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Campus Electric Load Profile (PEC Load Profiler)

Friday Saturday Sunday Monday Tuesday Wednesday Thursday

$1,935 $1,784 $2,049 $1,617 $938

In 2009, Thursday was Christmas Eve and was a campus holiday. The University was closed, hence the low comparative energy use on Wednesday and Thursday.

Energy SavingsNC State grew nearly 6% in gross square footage. This resulted in an increase in energy consumption between 2009 and 2010. When normalizing for this increase in campus size, energy consumption dropped between 2009 and 2010, saving the University more than $8,300 in avoided costs. 14

Intersession Energy Savings InitiativeLessons Learned and Projections for 2011

Thanksgiving Holiday Setback• Key Highlights

- $8,500 in Energy Costs Avoided

- 53 Metric Tons of CO2 Emissions Avoided (MTCO2)

• Lessons Learned- Due to program duration, better communication is required to

reach the campus community and to ensure plug loads, lights, etc. are disconnected.

- More coordination among facilities staff should occur to ensure that high energy-consuming equipment is scheduled properly. If equipment must be used during setback period, consider when the event occurs and determine most cost-effective method of operation.

• Opportunities for 2011- Spring Break, Saturday, March 5 through Sunday, March 13:

Minimally consider unoccupied scheduling for the 9-day period. Set a stretch goal to shut down buildings during the first 7 days, and recover the buildings during the second weekend, setting the schedules to a typical weekend occupancy.

- Determine buildings that can be scheduled with more granularity and work with BM&O to set detailed schedules within these buildings. SAS Hall is currently a pilot building for detailed scheduling.

Pre-Holiday Setback • Key Highlights

- $8,300 in Energy Costs Avoided

- 47 Metric Tons of CO2 Emissions Avoided (MTeCO2)

• Lessons Learned- Since days of the week change between program years,

metrics for weekdays and weekends must be created, evaluated and incorporated into the energy analysis.

- A greater impact is expected if additional outreach to faculty and staff is presented, and additional opportunities may become apparent as Energy Management and BM&O work together to determine and implement detailed building schedules.

- Temperature and relative humidity play an important role in campus energy use, but it is expected that there is a greater impact on steam and chilled water production within the Central Utility Plants.

• Opportunities for 2011- Provide additional outreach to address faculty and staff

concerns when expanding the Intersession Energy Savings Initiative to include additional days.

- Sub-meter energy consumption where possible and provide incentives for department or organization with the largest relative energy savings during the intersession period.

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