Ductless Heat Pumps (DHP) in Single Family Homes with Zonal Electric Heat UES Measure Update Regional Technical Forum June 17, 2014

Today’s Agenda Measure Overview Staff Highlighted Areas Summary of Updates Measure Materials Summary of Changes to Savings, Cost, TRC Proposed Decision 2

DHP Measure Overview Current Category: Proven Current Status: Active Current Sunset Date: 1/31/2017 Reason for Update/Review: Integration of U 0 -based SEEM calibration adopted at the May 2014 RTF meeting expected to change savings by more than 10 percentMay 2014 RTF meeting New calibration 3

Staff Highlighted Areas None (except for David Baylon’s issue - we’ll get to that…) 4

Summary of Updates Minor update to U 0 -based DHP calibration presented in May presented in May – Discovered some supplemental fuel heating in the DHP 95-population used for Phase I Calibration – Phase I Calibration should contain no non-electric supplemental fuel heating – Staff filtered out supplemental fuel users from Phase I dataset (nine homes) – Caused minor change in calibration parameter “theta” (0.55 to 0.53), causing slight decrease in DHP electric heating consumption 5

Summary of Updates (continued) Integrated U 0 calibration with new savings calculation method (i.e. S2 rather than S1) into DHP measure analysisS2 rather than S1 Major workbook renovation – Cleaned up and reorganized UES measure workbook (removed old calibration work) – Developed SEEM analysis workbook using new SEEM template This is linked to the UES measure workbook – Developed stand-alone Calibration workbook Also linked to UES measure workbook 6

Measure Materials 7 Calibration Workbook DHP Calibration Report DHP SEEM Analysis Runs DHP UES Workbook CalibrationSEEM Analysis UES Documentation and derivation of Phase I/II calibration SEEM inputs and outputs Derivation of unscreened heating savings Derivation of screened heating savings and cooling savings (all) Summary of total savings, cost, TRC

Summary of Changes to Savings, Cost, TRC Major changes – Basing calibration of savings on pre/post consumption (i.e., on S2 rather than pre/post savings, S1) on S2 rather than pre/post savings, S1 Affects HZ3 more significantly than HZs 1 and 2 – Adjustment for partial occupancy and misbehaved bills Causes a 10-15% reduction in savings across all zones Heating Savings: – Unscreened HZ1 savings down from 2,719 to 2,395 kWh/yr HZ2 savings down from 2,604 to 2,381 kWh/yr HZ3 savings up from 311 to 873 kWh/yr – Screened (applicable to HZ3 only) PASS screen savings up from 1,339 to 1,558 kWh/yr FAIL screen savings up from 157 to 702 kWh/yr 8

Summary of Changes to Savings, Cost, TRC (continued) Cooling Savings – No change Cost – No change TRC – Cost-effectiveness unchanged for most measures – See “Presentation” tab of UES workbook for changesUES workbook 9

Staff Highlighted Areas David Baylon would like us to revisit the Phase II calibration for single family houses Phase II calibration – Issue is how we handled “unoccupied houses / misbehaved bills.” Currently VBDD estimates are used within the regression. Options: – Throw them all out – Zero them all out – Leave as-is (use VBDD estimates) 10

Highlighted Areas (continued) Throw them all out – Assumes “unoccupied/misbehaved” houses consume as much heating energy as the average. Zero them all out – Assumes “unoccupied/misbehaved” houses use no heating energy. Leave as-is – Uses completely unreliable VBDD estimates for heating energy, but it is less extreme than the alternatives. 11

Proposed Decision “I _____ move to: A: “Approve as proposed the updates to the Ductless Heat Pumps (DHP) in Single Family Homes with Zonal Electric Heat UES measure and [direct]/[don’t direct] staff to revisit Phase II for the misbehaved/unoccupied house adjustment.” Or B: “Revisit Phase II for misbehaved/unoccupied house adjustment before finalizing the DHP UES.” 12

Backup Slides 13

DHP Re-Calibration Moving to Uo-based Calibration (away from Thermostat-based Calibration) Regional Technical Forum May 13, 2014

Phase I Adjustment to SEEM Output to Match Bills (for Houses with “well-known” Heating Energy Use) 15

Background: DHP Calibration Existing DHP Phase I Calibration, approved in July 2013, is based on the old Thermostat Setting calibration method:DHP Phase I Calibration 16

Goal: Determine U o -based Phase I Calibration Factors for DHPs 17

Methodology 18

Comparison Heating Zone Heating Electric Savings (kWh/yr)Difference from Original Original 12,7192,5932,528-5%-7% 22,6042,5652,479-1%-5% %3% 19

Proposed Calibration Factors (DHP in Green) 20

Decision “I _____ move that the RTF adopt the revised U o -based Phase I calibration adjustment factors for DHP’s.” 21

Phase II Adjustment to Electric Energy Use for Non-electric Fuel usage, Unoccupied Houses, and houses with otherwise misbehaved bills 22

Background Phase II Adjustments: For program-like houses (permanent electric heat, no non- electric FAF or boiler), the adjustments address: – Non-utility heating sources, – Program-permitted gas heat sources (e.g., gas fireplaces), and – Other SEEM Phase I calibration filters See September 2013 RTF meeting presentation for more detailspresentation Today’s Goal: Determine values for DHP. 23

Available Data Source: DHP Pilot Study, R 2 ≥ Source: RBSA SF, Zonal Electric Source: SEEM runs, Phase I applied

Two UES Analysis Methods The next two slides show the two methods in detail. The difference between the two methods (in words): – S 1 uses the ratio of savings from the average house to non- supplemental fuel houses. – S 2 uses the ratio of energy use from the average house to non- supplemental fuel houses. Q: Which one’s better, correct? – They seem to offer the same correctness. S 2 aligns better with our guidelines: Determines baseline and efficient case consumptions separately. – The S 2 Method will allow us to generate Phase II calibration factors for DHP’s (The S 1 Method will not). The S 2 Method aligns with our need to assign a separate “wood heat” adjustment factor to DHP’s. – But they give different answers (especially in HZ3): 25 Whether we should revisit the DHP UES is out of scope for this presentation.

Background: DHP UES Savings Methodology 26

Background: DHP UES Alternative Methodology 27

Proposed Methodology 28 We continue to have no fully satisfying solution. Supplemental fuels use has been a difficult thing to pin down; it still requires a fair amount of judgment for DHP’s.

Step 1 – Apply implied adjustment to DHP Remember there’s a component of the adjustments that represents unoccupied houses and houses with otherwise misbehaved bills. We’ll assume DHP houses, on average, have the same results as other heating systems (which are based on RBSA data). 29

Step 2 – Re-state Known Adjustments 30

Step 3 – Find R 2.D(RBSA) by using S2 from the DHP UES alternate analysis. 31 Solve for R 2.D(RBSA)

Step 4 – Work backward to fill in the blanks. 32 Negative value doesn’t make sense, we’ll need to fix that.

Step 5 – Re-assign negative value in HZ3. 33 Again, not a completely satisfying solution, but it doesn’t affect savings too much: S 2 for HZ3 changes from 970 kWh/yr to 1,043 kWh/yr with this “tweak”.

Decision “I _____ move that the RTF adopt the Phase II calibration adjustment factors for DHP’s.” 34