1. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Commercial Windows and Insulation RTF November 2, 2010

2. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 2 The Plan for Commercial Weatherization  Goal Expand deemed savings for commercial windows and insulation to additional building types and sizes at December 7 th RTF meeting  Today Review regional potential Review existing data from multiple sources Gather RTF input on current analysis and methodology for developing new measures − Where are current data sufficient? − Where could additional modeling be an efficient method for additional measures? Given size of potential, find balance between available data and time/money spent on further analysis  December 7 th Present expanded measures based on today’s discussion

3. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Current RTF Measures Commercial Windows 3

4. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Current RTF Measures Commercial Insulation 4

5. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 5 Commercial Windows

6. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 6 Regional Savings Potential  Relatively small total savings, but important for many small/rural utilities in the region Post 2011 Small, rural, residential workgroup  Savings potential 6 th Plan - Commercial Windows, Retrofits – 21 aMW Navigant analysis of CBSA, assuming 10 kWh/sq. ft. – 17 aMW (to be discussed in the following slides)

7. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N  Different savings by building type, heating type, cooling type (specified per square foot of building space)  Includes variety of existing {single, double}, frame material  2/3 (21 aMW) from retrofit 7 6 th Plan Technical Potential

8. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 8 CBSA – Building Square Footage Regional building stock with single pane windows and electric heating 8

9. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 9 CBSA – aMW Savings Potential Assuming 10 kWh / sq ft. of window, electric resistance heating (mid point of PTR savings) Savings scaled down for heat pumps 17.4 aMW (12.8 a MW excluding heat pumps) Buildings with single pane windows and electric heating 9

10. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 10 Savings Data Sources  Savings vary across modeling efforts, and are sensitive to model assumptions  Models suggest that savings vary by building use building size climate zone

11. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 11 Current PTR  Existing window type not specified in measure  Analysis based on EZSim Modeling U0.65 to U0.34 small office and retail buildings (1,104 sq. ft.)

12. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 12 NEEA/LBNL  U0.55 to U0.30  Savings range for range of solar heat gain (SHG) and shading scenarios  Gas savings converted to electric savings by Navigant (assuming 95% electric heat efficiency, 65% gas heat efficiency)  Reference “Analysis of window energy savings in commercial buildings in the Pacific Northwest”, Final Report LBNL-60379, prepared by Joe Huang an Mehry Yazdanian January, 2007 and data tables in.xls. kWh/sq. ft savings

13. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 13 eQUEST, CA Prototype Buildings kWh/ sq. ft. of window  Conducted by Navigant as part of this scoping analysis  No adjustment of buildings to older NW building characteristics  Key points:  Savings persist for larger size buildings  Savings for single pane to Energy Star are about twice as large as savings for double pane (U0.55) to Energy Star

14. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 14 OR DOE Tax Credit  Savings estimate: 12 to 20 kWh per sq. ft.  Single pane (U 1.1) to U 0.35  Used simplified heat loss approach. Have not been able to find supporting analysis  Referenced in: “Commercial Windows Initiative, Market Progress Evaluation Report, No. 1”, Prepared by Heschong Mahone Group, Inc. Report #E05-137, March 23, 2005 http://www.neea.org/research/reportdetail.aspx?ID=97

15. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 15 Cost  Current deemed cost - $21.56/sq. ft Data from 2007, 2008. Not adjusted to $2006 Based on residential costs Recent Summit Blue/Navigant study of material costs in NW agree well with deemed costs Larger commercial projects may have lower costs

16. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Cost Proposal  $21.56 / square foot (residential cost) up to 650 sq. ft. of window (~10,000 sq. ft building).  $16.71 (75% of residential cost) for projects larger than 650 sq. ft. 16

17. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 17 Cost Effectiveness Ranges  Using available data, consider the likely range of savings for varying existing window type, business type, size, and climate.

18. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Proposed Next Steps  For December 7 th … Cost – keep existing costs Savings - Use CBSA/EZSim to examine a range of building type/size/climate based on today’s discussion Group results as appropriate into measures  Building type/usage: Given the large potential for “Other” buildings, consider other options for categorization: Categorize by hours of use (programmatically feasible?) A single, weighted average savings for all building types An “other” category, in addition to “office” and “retail” 18

19. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 19 Commercial Insulation  Attic  Wall  Floor  Foundation perimeter (for slab-on-grade construction)

20. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 20 Currently Deemed Savings  Based on EZSim modeling of small office and retail buildings (1,100 sq. ft)  No other data on commercial insulation measures found

21. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 21 6 th Power Plan Technical Potential  6 th Plan only includes roof insulation in supply curves  Roof insulation is not currently in PTR

22. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Approach for Calculating Potential  Savings estimates all based on current PTR savings values expanded to buildings in CBSA database that were identified as applicable Example: − If building doesn’t have electric heating, not included − If concrete building, not considering wall insulation 22

23. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 23 CBSA and RTF Analysis Identify candidate buildings in CBSA for insulation retrofits  Pre-1985 buildings only (more likely to be un-insulated)  Electric-fuel heating (resistance, heat pump) only CBSA does not indicate the presence or absence of insulation.  CBECS for NW areas indicates that ~90% of pre-1985 buildings have not had an insulation retrofit. No air conditioning assumed in savings The current RTF deemed numbers do not consider air conditioning (applicable for buildings up to 5,000 sq ft). This will be more of a factor for larger buildings.

24. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N CBSA Potential Savings Summary aMW retrofit technical potential, by building size 24

25. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N CBSA Potential Savings Summary aMW retrofit technical potential, by building type 25

26. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Attic Insulation Savings R0 to R38 (RTF weatherization specs)  3.38 to 5.89 kWh/sq ft, depending on heating zone and {office, retail}. current deemed savings for commercial buildings up to 5,000 sq ft R19 to R49 (RTF weatherization specs)  Currently not a deemed commercial measure  Approximately 1/3 of savings of R0 to R38, based on residential deemed values This suggests 1.1 to 1.9 kWh/sq ft savings 26

27. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Underfloor Insulation Savings R0 to R30 (RTF weatherization specs)  2.0 to 3.7 kWh/sq ft, depending on heating zone and {office, retail}. current deemed savings for commercial buildings up to 5,000 sq ft 27

28. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Wall Insulation Savings RTF Weatherization Specs:  R0 to R15 (4” unfinished wall)  R21 (6” unfinished wall)  R11 (exterior cavities, blown in)  1.5 to 3.2 kWh/sq ft savings 28

29. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Exterior Perimeter Savings R0 to R10 ( RTF Weatherization Specs)  Currently no deemed savings for this measure  Assumed 1.0 kWh for this analysis  Savings from PNNL analysis for Montana Office − 0.7 kWh/ft savings for heat, 0.2 kWh/ft increase for cooling Gas Station/Retail − 2.2 kWh/ft savings for heat, 0.3 kWh/ft increase for cooling  Costs per linear foot range from $20 to $45, depending on excavation and refinish costs Navigant survey of contractors throughout the NW 29

30. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Savings Summary  Current savings applies to small office and retail buildings, based on modeled 1,100 sq. ft buildings.  For larger buildings, internal heat loads and AC will reduce savings.  Savings also dependent on hours of use of space conditioning. 30

31. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Cost and Cost Effectiveness  Current PTR costs, based on residential projects 31

32. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Proposal  Keep current insulation costs for buildings under 10,000 sq ft. Discount costs by 25% for buildings 10,000 sq ft. and above  Option 1: Apply current kWh/unit savings to building types identified by CBSA Analysis of very small buildings Hasn’t been other analyses  Option 2: (recommended): Expand analysis that was done to larger building, keeping simple Done through modeling, expanding on EZSim modeling done for small buildings, − using CBSA for building and billing data − make reasonable assumptions about existing insulation levels Different savings number for different building sizes 32

33. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N Back Up Slides 33

34. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 34 Analysis – Attic Insulation Unclear from CBSA which buildings have attics or other top-of-building space suitable for attic insulation R0 to R38 (RTF weatherization specs)  3.38 to 5.89 kWh/sq ft, depending on heating zone and {office, retail}. current deemed savings for commercial buildings up to 5,000 sq ft  Buildings prior to 1985 eligible. R19 to R49 (RTF weatherization specs)  Currently not a deemed commercial measure  Approximately 1/3 of savings of R0 to R38, based on residential deemed values This suggests 1.1. to 1.9 kWh/sq ft savings  Buildings prior to 2000 eligible. School assumptions–  35% with un-insulated attics,  20% with moderately insulated attics,  45% without attics or already with good insulation Small building (up to 2,000 sq ft) assumptions –  50% have attics, 20% of these already have some insulation  4% have more insulation than R19 Medium building (2,000 to 10,000 square feet) assumptions –  15% have attics, 20% of these already have some insulation  1% have attics with some insulation (<R20) Large building (>10,000 square feet) assumptions  5% have suitable space for attic insulation, 20% of these already have some attic insulation <R20 34

35. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 35 Analysis – Attic Insulation – R0 to R38 aMW retrofit technical potential, by building size and type 35

36. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 36 Analysis – Attic Insulation – R19 to R49 aMW retrofit technical potential, by building size and type 36

37. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 37 CBSA Potential: Attic Insulation Potential (aMW) R0 to R39 R19 to 49 Note scale difference

38. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 38 Underfloor Insulation Potential Savings R0 to R30 (RTF weatherization specs)  2.0 to 3.7 kWh/sq ft, depending on heating zone and {office, retail}. current deemed savings for commercial buildings up to 5,000 sq ft  Not applicable to slab-on-grade construction  Assumed all remaining building stock is eligible for this (0% saturation)  35% of buildings assumed to have technical constraints on implementations.  10% of remaining building stock assumed to have already done this measure

39. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 39 Analysis – Underfloor Insulation – R0 to R30 aMW retrofit technical potential, by building size and type 39

40. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 40 Underfloor Insulation Potential (aMW) R0 to R30

41. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 41 Walls – Savings Potential RTF Weatherization Specs:  R0 to R15 (4” unfinished wall)  R21 (6” unfinished wall)  R11 (exterior cavities, blown in)  1.5 to 3.2 kWh/sq ft savings  Not applicable brick, concrete, or concrete block wall surfaced  Assumed 10% saturation of all remaining building stock

42. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 42 Analysis – Wall Insulation aMW retrofit technical potential, by building size and type 42

43. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 43 Wall Insulation Potential (aMW) R0 to R11

44. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 44 Exterior Perimeter R0 to R10 ( RTF Weatherization Specs)  Vertical insulation to exterior of perimeter foundation, 2’ below grade  Currently no deemed savings for this measure  Savings from PNNL analysis for Montana Office 0.7 kWh/ ft savings for heat, 0.2 kWh/sq. ft. increase for cooling Gas Station/Retail 2.2 kWh/sq ft savings for heat, 0.3 kWh/sq. ft. increase for cooling Assumed 1.0 kWh for this analysis  Costs for this measure are prohibitive because of the need for excavation and refinishing

45. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 45 Analysis – Perimeter Insulation aMW retrofit technical potential, by building size and type 45

46. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 46 Perimeter Potential (aMW) R0 to R10

47. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N CBSA “Other” Building Types 47