Analysis of Weatherization Measures Options for Savings Methodology and Presentation of Costs from 6 th Plan Regional Technical Forum May 4 th, 2010

The Old Method “SUNDAY” Whole House Energy Use Calculation Tool – Temperature Bin and Solar Gain Analysis – Calibrated to metered usage – Zonal heating system assumed – Inputs House UA T-stat Settings Window area and orientation Internal Gains Duct characteristics “Last Measure In” Analysis – Weatherization measures are applied to the SUNDAY kWh versus UA curve, in order of cost-effectiveness, starting with the most cost-effective. – The last cost-effective measure’s kWh/∆UA is calculated – This kWh/∆UA is applied to all weatherization measures, as if each measure was the “last measure in” With SUNDAY, this is a conservative approach. Remember, the house’s existing insulation level is unknown. 2

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Last Measure In kWh/∆UA

The New (revised 6 th Plan) Method SEEM – An improved version of SUNDAY Hourly simulation Ground contact, crawlspace, attic, and ducts are more precisely modeled – Inputs calibrated to metered energy use (note: the original 6 th Plan values were not calibrated) Modified t-stat settings for zonal and electric forced air furnaces (66 deg F) Calibration was approved by the RTF in Nov 2009 – Zonal heating system assumed (no change) – Justification: weighted average COP of Heat Pump, FAF, and Zonal is about 1.0 Revised 6 th Plan Method Uses – “Last Measure In” Analysis No change – SEEM SEEM Runs include – 13 Weatherization Packages – 5 TMY3 Weather Inputs – 3 House Prototypes – Issues with this method kWh vs UA curve is not smooth Extrapolation required Doesn’t take into account FAF or HP’s …more details on following slides… 5 SEEM Weatherization Packages

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Last Measure In kWh/∆UA

Savings Comparison Old (Values in the PTR) versus New (revised 6 th Plan) But…another change to be aware of regarding the revised 6 th Plan analysis: – Revised U-values of Attics and Floors for revised 6 th Plan runs: – Un-insulated cases remained the same “R0” attic – U-value: – R-value: “R0” floor – U-value: – R-value: 9.4

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Alternatives to 6 th Plan Approach (In ascending order of correctness) Options 1a.Use “last measure in – by measure type” method - Applies a more representative kWh/∆UA factor to each measure 1b.Use constant slope for all measures - Eliminates “last measure in”, which doesn’t match SEEM’s output 2.Use SEEM to more directly calculate savings for the measure - This would require the most work to put together, but it would be the most correct method Additional Decisions to make under Option 2: i. Publish one melded value OR separate values for FAF, Zonal, and HP heating systems ii. Assume the “go to” case is a fully weatherized house with sealed ducts OR some assumed average case iii. There are probably many more decisions to make… Sub-Option A.All options above could implement an additional option: Use the 6th Plan’s mix of Forced Air furnace (36%), Zonal (42%), and Heat Pump (22%) heating systems. (instead of modeling zonal only) 14

15 Option 1a. Last Measure In - by Measure Type

16 Option 1a. Last Measure In - by Measure Type, with A. use heating system mixOption 1a. Last Measure In - by Measure Type, with Sub-Option A. use heating system mix

17 Option 1a. Last Measure In - by Measure Type, with Sub-Option A. use heating system mix

18 Option 1b. Constant Slope

19 Option 1b. Constant Slope, with Sub-Option A. use heating system mix

20 Option 1b. Constant Slope Option 1b. Constant Slope, with Sub-Option A. use heating system mix

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Decision on Savings Methodology Adopt 6 th Plan method or adopt another method? 24

Insulation Measure Costs Old Method (from 5 th Plan) – Average of four sources PSE Reported Costs EWEB Reported Costs Pacific PUD Reported Costs 1996 Power Plan Costs New Method – Median of ETO Program Data (electric) May 2007 through July 2008 – Cost per ft 2 = [Median (ETO cost/ft 2 /∆R)] × [∆ R] 25

ETO Cost Data for Ceiling Insulation 26 Median: 2.3¢/ft 2 /∆R

ETO Cost Data for Floor Insulation 27 Median: 4.7¢/ft 2 /∆R

ETO Cost Data for Wall Insulation 28 Median: 9.1¢/ft 2 /∆R

Window Measure Costs Used ETO Program data for Multifamily – Multifamily costs expected to best convey the cost of the efficiency improvement – Single Family costs expected to be biased high due to additional “features” U-0.30 to U-0.25 assumed to be $2.00/ft 2 – Recommend change to $1.36/ft 2 per June 2009 RTF meeting decision Gary Curtis’ research on costs for a 0.30 window package versus

ETO Data 30

Cost Comparisons 31 Window Replacement (Not Shown) PTR: $ th Plan: $20.07

Decision on Costs Adopt 6 th Plan method? 32