Table 5 and Table 6 present the distribution of HES electric and gas savings at the measure-level, comparing reported ex ante savings to estimates of evaluated gross savings. The savings estimates below reflect average household savings for participants receiving a given measure. 5. Comparison of Ex Ante and Evaluated Gross Savings by Measure—HES Electric Category Measure Reported Ex ante Savings (kWh/ Household) * (A) Gross Savings (kWh/ Household) (B) Realization Rate (B/A) Method Appliance Dehumidifier 382 31 8% Engineering Algorithm Appliance Freezer 705 66 9% Engineering Algorithm Appliance Refrigerator 243 189 78% Engineering Algorithm Appliance Clothes Washer 1,430 644 45% Engineering Algorithm HVAC Central AC 471 386 82% Engineering Algorithm HVAC Duct Sealing 309 103 33% Simulation Modeling HVAC Heating System Replacement 285 380 133% Engineering Algorithm HVAC Heat Pump 977 758 78% Engineering Algorithm HVAC Ductless Heat Pump** 2,844 1,311 46% Billing Analysis (±35%) HVAC Ground-Source Heat Pump 2,018 1,982 98% Engineering Algorithm Lighting Lighting 652 782 120% Billing Analysis (±6%) Other Other 259 259 100% Reported Ex Ante Shell Air Sealing 154 269 175% Billing Analysis (±21%) Shell Insulation Other 368 368 100% Reported Ex Ante Shell Windows 3,190 3,196 100% Engineering Algorithm Shell Attic Insulation 708 481 68% Simulation Modeling Shell Wall Insulation 1,876 1,575 84% Simulation Modeling
Table 8. Comparison of Ex Ante and Evaluated Gross Savings by Measure—HES-IE Electric Category Measure Reported Ex ante Savings (kWh/ Household)* (A) Gross Savings (kWh/ Household) (B) Realization Rate (B/A) Method Appliance Freezer 733 728 99% Billing Analysis (±32%) Appliance Refrigerator 758 318 42% Billing Analysis (±28%) Appliance Appliance Other 353 498 141% Billing Analysis (±24%) HVAC Central AC 98 98 100% Engineering Algorithm HVAC Duct Sealing 262 81 31% Simulation Modeling HVAC Ductless Heat Pump 1,731 803 46% Billing Analysis (±32%) HVAC Window AC 94 46 49% Engineering Algorithm Lighting Lighting 467 647 138% Billing Analysis (±6%) Other Other 637 637 100% Reported Ex Ante Shell Air Sealing 342 208 61% Simulation Modeling Shell Insulation Other 153 153 100% Reported Ex Ante Shell Windows 1,295 2,253 174% Engineering Algorithm Shell Attic Insulation 2,306 1,429 62% Simulation Modeling Shell Wall Insulation 2,326 716 31% Simulation Modeling Water Heat DWH Bundle 1,372 390 28% Engineering Algorithm Water Heat Temp Setback 87 78 90% Engineering Algorithm *Average ex ante savings per household are the program population, except for measures estimated through billing analysis, which are based on the billing analysis participant sample. Table 9. Comparison of Ex Ante and Evaluated Gross Savings by Measure—HES-IE Gas Category Measure Reported Ex ante Savings (CCF/ Gross Savings (CCF/ Realization Rate (B/A) Method
based on audit results) measures (including attic and wall; window replacements) HVAC equipment (including central AC heat pumps, ductless mini-splits) Water heater replacement CL&P’s HES-IE program includes four components or subprograms (SPs), as outlined in Table 11. UI’s HES-IE program also collaborates with the Weatherization Assistance Program (WAP) in a manner similar to SP1 for CL&P, but UI does not utilize the same subprogram structure as CL&P. Table 11. Overview of CL&P HES-IE Subprograms HES-IE Component Description SP1: Weatherization Projects/ Department of Energy (DOE) Approved Jobs* Utility-leveraged weatherization projects, implemented by agency networks that deliver the federally funded WAP. SP2: Individual Customer Work Orders Comprehensive audit and delivery of energy-efficiency and weatherization services. SP3: Multifamily Comprehensive Projects Comprehensive audits and delivery of energy-efficiency and weatherization services specific to multifamily buildings, in 75% of residents meet income qualifications. SP4: Neighborhood Canvassing Neighborhoods with anticipated income-eligible customers receive HES-IE marketing and direct-installation measures, leading to participation in SP2. *Currently administered by the Connecticut Department of Energy & Environmental Protection, but previously under the jurisdiction of the Connecticut Department of Social Services. Report Organization This report divides into the following sections: Methodology, explains the impact-evaluation tasks, data sources, and analytical approach; Findings, which detail key impact results from evaluation activities for the HES and HES-IE programs, at both program and measure levels as well as results specific to whole-house billing analysis of HES-IE SP1 and SP4; and Appendices, which provide supplemental details regarding the impact evaluation methods. door
Table 15. Comparison of Ex Ante and Evaluated Gross Savings by Measure—HES Electric Category Measure Reported Ex ante Savings (kWh/ Household) * (A) Gross Savings (kWh/ Household) (B) Realization Rate (B/A) Method Appliance Dehumidifier 382 31 8% Engineering Algorithm Appliance Freezer 705 66 9% Engineering Algorithm Appliance Refrigerator 243 189 78% Engineering Algorithm Appliance Clothes Washer 1,430 644 45% Engineering Algorithm HVAC Central AC 471 386 82% Engineering Algorithm HVAC Duct Sealing 309 103 33% Simulation Modeling HVAC Heating System Replacement 285 380 133% Engineering Algorithm HVAC Heat Pump 997 758 78% Engineering Algorithm HVAC Ductless Heat Pump** 2,844 1,311 46% Billing Analysis (±35%) HVAC Ground-Source Heat Pump 2,018 1,982 98% Engineering Algorithm Lighting Lighting 652 782 120% Billing Analysis (±6%) Other Other 259 259 100% Reported Ex Ante Shell Air Sealing 154 269 175% Billing Analysis (±21%) Shell Insulation Other 368 368 100% Reported Ex Ante Shell Windows 3,190 3,196 100% Engineering Algorithm Shell Attic Insulation 708 481 68% Simulation Modeling Shell Wall Insulation 1,876 1,575 84% Simulation Modeling Water Heat Heat Pump Water Heater 1,762 1,762 100% Reported Ex Ante Water Heat DWH Bundle 482 359 82% Billing Analysis (±21%)
Table 16. Comparison of Ex Ante and Evaluated Gross Savings by Measure—HES Gas Category Measure Reported Ex ante Savings (CCF / Household) * (A) Gross Savings (CCF/ Household) (B) Realization Rate (B/A) Method Appliance Clothes Washer 20 2 8% Engineering Algorithm HVAC Duct Sealing 45 19 42% Simulation Modeling HVAC Heating System Replacement 1,004 229 23% Engineering Algorithm Shell Air Sealing 62 57 91% Billing Analysis (±14%) Shell Insulation Other 175 175 100% Reported Ex Ante Shell Windows 136 147 108% Engineering Algorithm Shell Insulation 179 135 76% Simulation Modeling Shell Wall Insulation 449 224 50% Simulation Modeling Water Heat Water Heater Replacement 56 56 100% Reported Ex Ante Water Heat DWH Bundle 17 14 84% Engineering Algorithm *Average ex ante savings per household are based on the program population, except for measures estimated through billing analysis, which are based on the billing analysis participant sample. Measure-Level Savings This section addresses evaluated gross savings estimates for all HES measures, covering electric, natural gas, and oil/propane fuel types. The results are grouped by fuel savings and are presented for distinct measures and/or measure categories. HES Electric Savings The billing analysis provided estimates of electric savings for several HES measure categories: lighting, ductless heat pumps, air sealing, insulation other (containing a mix of attic and wall installations), and the DHW bundle (containing showerheads, pipe insulation, and aerators). All other estimates of electric savings presented in this section were determined using engineering algorithms and simulation modeling.
Table 36. HES Billing Analysis Realization Rate Summary for Air Sealing and Insulation Other Measure Gross Model Savings (CCF) Reported Ex Ante Savings (CCF)* Realization Rate Model Savings as Percent of Pre-Usage Reported Ex Ante Savings as Percent of Air Sealing 57 62 91% 5% 6% *Average ex ante savings is based on the participant sample used in the billing analysis and may vary from averages based on the program population. Simulation Modeling Results The Evaluation Team used detail provided in the utility tracking data (for each building type and heating fuel combination) to assess corresponding pre- and post-installation information for each measure analyzed using the calibrated simulation approach. Table 37 presents these details, including average pre- and post-installation insulation levels (weighted by square footage installed) and changes in air and duct-sealing levels. Table 37. HES Gas—Shell and Duct-Sealing Measure Distribution and Installation Details Measure Participants* Pre-Condition Post-Condition Average % Leakage Reduction Units Duct Sealing 1,192 522 393 25% CFM 25 Attic Insulation 383 R5 R32 n/a R-Value Wall Insulation 54 R0.5 R15.5 n/a R-Value *Count of participants reflects the number with ex ante savings reported for a given measure. The Evaluation Team used the energy models to calculate the savings percentage of weather-sensitive loads for each measure, which were then applied to pre-period, weather-sensitive usage for each model to calculate evaluated energy savings. Table 38 presents the weighted household-level gas savings for each measure and the realization rates compared to average ex ante savings, along with savings percentages of weather-sensitive loads. Table 38. HES Gas—Weighted Household Savings for Shell and Duct Measures Measures Average Ex Ante Savings (CCF) Average Consumption (CCF) Savings as % of Load Average Evaluated Gross Savings (CCF) Realization Rate Duct Sealing 45 790 2.3% 19 42% Attic Insulation 179 964 14.0% 135 76% Wall Insulation 449 801 27.9% 224 50% Differences between ex ante and evaluated savings for shell and duct sealing measures estimated using building simulation models are presented above in the HES Electric Savings section.
Realization Rate Table 79 provides realization rates, based on participant gross and adjusted gross savings for the billing analysis sample. Table 79. HES-IE SP1 and SP4 Natural Gas Billing Analysis: Realization Rate Summary HES-IE Subprogram Model Savings (CCF) Reported Ex Ante Savings (CCF) Realization Rate Savings as Percent of Pre-Usage Reported Ex Ante Savings as Percent of Pre-Usage SP1 Gross 97 110 89% 10% 11% Adjusted Gross 82 110 75% 8% 11% SP4 Gross 43 60 71% 6% 8% Adjusted 32 60 53% 4% 8%