1 NORTHWEST ENERGY EFFICIENCY ALLIANCE

Northwest Ductless Heat Pump Pilot ProjectImpact & Process Evaluation: Billing Analysis

Ecotope, Inc.February 20, 2013

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Agenda

Introduction

Research Objectives

Recap of Metering Results

Methodology

Highlights of Findings

Conclusions

Q & A

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Introduction

4

DHP Impact & Process Evaluation Overview

UES Workbook

Billing Analysis ~4,000 Participants

Market Progress Evaluation~300 Participants

Field Monitoring95 Participants

Lab Testing 2

units

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DHP Evaluation Timeline

2009

• Install field meters• Launch lab tests• Collect data for Wave 1 market progress evaluation

2010• Wave 1 market progress report• Ongoing field monitoring

2011

• Lab analysis report• Wave 2 market progress report• Decommission field sites

2012• Metering report

2013

• Billing analysis report• Cost effectiveness analysis• UES workbook• Final Summary report

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Research Objectives

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Billing Analysis Research Objectives

Assess the overall savings and the space heating savings from the DHP installations in the pilot project

Establish savings in electric space heating brought on by this equipment

Determine the impact of occupancy and other “takeback” effects on observed savings

Assess the impact of supplemental fuels on DHP savings

Confirm results of previous metering study and lab testing

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Recap of Metering Results

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Metered Analysis Summary

Total savings derived from the heat output of the DHP

Billing savings derived from the pre and post installation bills and metered heating use

Simple regression analysis (CDA) to develop determinants of savings

SEEM calibration based on metered and baseline heating estimates Temperature adjustments, 66.8° to 69.5° Calibrated to heating energy use and savings

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DHP Total Savings Results

Cluster

Savings from COP (kWh/yr)

nMean SDWillamette 4148 2061 18

Puget Sound 3812 1981 19

Inland Empire 3264 1470 11

Boise/Twin 4184 1871 8

Eastern Idaho 3924 1767 9

Total 3887 1844 65

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DHP Bill Savings Results

Cluster

DHP Savings (kWh/yr)

nMean SDWillamette 3316 2121 26

Puget Sound 3043 2357 25

Inland Empire 1882 1580 16

Boise/Twin 3628 2985 16

Eastern Idaho 3307 3230 10

Average/Total 3049 2424 93

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Modeled Savings Estimates, SEEM

Cluster

Calibrated to BillsPre 66.8°F - Post 69.5°F

(kWh/yr)Calibrated to COPPre 66.8°F - Post 66.8°F (kWh/yr)

nMean SD Mean SDWillamette 2435 1227 3424 1480 27

Puget Sound 3073 1521 4015 1809 25

Inland Empire 2724 1485 3719 1754 17

Boise/Twin 3742 1695 4874 2007 16

Eastern Idaho 2618 948 3939 1283 10

Average/Total 2894 1460 3931 1732 95

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Billing Analysis Methodology

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Distribution of DHP Pilot Sites (n=3,899)

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Data Collection

Bills requested for all pilot sites (3,899) 3,748 sites received, 3,629 sites with useable pre and

post installation records PRISM (VBDD) analysis

Estimated heating energy, savings with DHP installation Include R2 measure of the quality of the heating

estimate All sites that had adequate bills evaluated

Installation questionnaire House size and customer demographics Supplemental heating Installation cost

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Highlights of Findings

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All Useable Cases

Cluster

Space Heating Savings

All Cases Screened CaseskWh/yr n kWh/yr n

Willamette 2285 2090 2416 2001Puget Sound 1677 752 1913 701Coastal 1463 288 1930 233Inland Empire 780 141 856 126Boise/Twin 1407 96 1572 92Eastern Idaho 503 84 496 81Tri-Cities 861 55 1035 51Western Montana 289 123 813 105Total 1882 3629 2081 3390

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Supplemental Fuels

High incidence of supplemental fuels in pilot program Overall 33.2% of participants report supplemental fuels RBSA region wide electric heat customers report 35.9% reported

supplemental fuels Clear indications of large impact on savings Larger incidence of supplemental fuel use in Eastern

market clusters Western Montana 67% Other rural areas (Western and Eastern) wood heat saturation of

~40% Supplemental fuels assigned based on installation

questionnaire Similar to the screening process in selecting the metering sample

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Supplemental Fuels

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Screened VBDD Results

Screened Datasets

Space Heat Consumption (kWh) Electric Space Heat

Saved(kWh)

nPre Install Post Install

All Sites with Valid Bills     Mean  SD  

All 7121 5241 1880 2954 3629R2>.45 7424 5350 2074 2853 3387R2>.65 7714 5422 2292 2728 3035

Supplemental Fuel Not Used      All 7910 5223 2687 2655 2477R2>.45 7999 5265 2734 2595 2407R2>.65 8105 5313 2792 2553 2256

Supplemental Fuel Used      All 5424 5279 145 2815 1152R2>.45 6011 5559 452 2811 980R2>.65 6582 5738 843 2703 779

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CDA Regression

Specified as an alternative to screening n=3621 Use robust regression specs to reduce

impact of scatter Specification:

SHsaved=c1SHpre+c2SuppFuel+C

c1 and c2: estimated coefficients C: constant term

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Definitions of CDA Variables

The coefficient on pre-installation space heat (c1) predicts the space heating savings (controlling for

other factors). The coefficient on supplemental fuel use (c2)

predicts reduction in savings. The constant term accounts for the other factors

that reduce savings (thermostat settings, erratic occupancy, etc.).

Supplemental fuels coefficient and the constant term account for the savings reduction due to occupant effects: non-energy and supplemental fuel benefits.

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Regression Results

Climate Zone Segment

Parameter

nc1 c2 C

Western 0.487 -973 -768 3122

Eastern 0.223 -1,152 -300 375

W. Montana 0.249 -1,683 -416 123

All 0.434 -1,110 -561 3620

SHsaved=c1SHpre+c2SuppFuel+C

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CDA Predicted Space Heating Savings

Cluster

Predicted Savings

nMean SD

Willamette 3436 2,055 2,086

Puget Sound 3308 1,783 752

Coastal 2997 2,074 285

Inland Empire 1823 1,236 140

Boise/Twin 2115 947 96

Eastern Idaho 2088 935 84

Tri-Cities 1264 938 55

Western Montana 2036 1347 123

Total 3166 1969 3621

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Segmented Regression Results

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CDA Observations

CDA regression recovers the mean savings estimated

The CDA analysis conducted on themetered sample: c1= .470 for western climates

.240 for eastern climates c2 is essentially zero (the sample was screened) Constant term in this sample is zero 20% difference between the billing analysis results

and measured DHP heat output

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Conclusions

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Conclusions

Once similar screening for supplemental heat is done: results agree with metered analysis results.

Supplemental fuels reduce savings ~1000 kWh W. Montana requires more severe adjustments

The impact of DHP on space heat without the take back effects: 48% in the western climates 22% in the eastern climates

Program design may need to be modified for more severe climates

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Questions & Answers