1 NORTHWEST ENERGY EFFICIENCY ALLIANCE Northwest Ductless Heat Pump Pilot Project Impact & Process Evaluation: Billing Analysis Ecotope, Inc. February 20, 2013
2 Agenda Introduction Research Objectives Recap of Metering Results Methodology Highlights of Findings Conclusions Q & A
3 Introduction
4 DHP Impact & Process Evaluation Overview UES Workbook Billing Analysis ~4,000 Participants Market Progress Evaluation ~300 Participants Field Monitoring 95 Participants Lab Testing 2 units
5 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
6 Research Objectives
7 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
8 Recap of Metering Results
9 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
10 DHP Total Savings Results Cluster Savings from COP (kWh/yr) n MeanSD Willamette Puget Sound Inland Empire Boise/Twin Eastern Idaho Total
11 DHP Bill Savings Results Cluster DHP Savings (kWh/yr) n MeanSD Willamette Puget Sound Inland Empire Boise/Twin Eastern Idaho Average/Total
12 Modeled Savings Estimates, SEEM Cluster Calibrated to Bills Pre 66.8 ° F - Post 69.5°F (kWh/yr) Calibrated to COP Pre 66.8°F - Post 66.8°F (kWh/yr) n MeanSDMeanSD Willamette Puget Sound Inland Empire Boise/Twin Eastern Idaho Average/Total
13 Billing Analysis Methodology
14 Distribution of DHP Pilot Sites (n=3,899)
15 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 R 2 measure of the quality of the heating estima te All sites that had adequate bills evaluated Installation questionnaire House size and customer demographics Supplemental heating Installation cost
16 Highlights of Findings
17 All Useable Cases Cluster Space Heating Savings All CasesScreened Cases kWh/yrn n Willamette Puget Sound Coastal Inland Empire Boise/Twin Eastern Idaho Tri-Cities Western Montana Total
18 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
19 Supplemental Fuels
20 Screened VBDD Results Screened Datasets Space Heat Consumption (kWh) Electric Space Heat Saved (kWh) n Pre InstallPost Install All Sites with Valid Bills Mean SD All R 2 > R 2 > Supplemental Fuel Not Used All R 2 > R 2 > Supplemental Fuel Used All R 2 > R 2 >
21 CDA Regression Specified as an alternative to screening n=3621 Use robust regression specs to reduce impact of scatter Specification: SH saved =c 1 SH pre +c 2 SuppFuel+C c 1 and c 2 : estimated coefficients C: constant term
22 Definitions of CDA Variables The coefficient on pre-installation space heat (c 1 ) predicts the space heating savings (controlling for other factors). The coefficient on supplemental fuel use (c 2 ) 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.
23 Regression Results Climate Zone Segment Parameter n c1c1 c2c2 C Western Eastern , W. Montana , All , SH saved =c 1 SH pre +c 2 SuppFuel+C
24 CDA Predicted Space Heating Savings Cluster Predicted Savings n MeanSD Willamette34362,0552,086 Puget Sound33081, Coastal29972, Inland Empire18231, Boise/Twin Eastern Idaho Tri-Cities Western Montana Total
25 Segmented Regression Results
26 CDA Observations CDA regression recovers the mean savings estimated The CDA analysis conducted on the metered sample: c1=.470 for western climates.240 for eastern climates c 2 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
27 Conclusions
28 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
29 Questions & Answers