Residential Single Family and Manufactured Home Heat Pump Water Heaters Christian Douglass Regional Technical Forum 4/14/2015

Overview Measure sunsets this month, so we need to decide where to set measure category and status based on where we are today Measure currently “Provisional” and “Under Review” Research plan has been drafted but research sponsor discussions are still in progress CAT proposes categorizing as “Planning” until a sponsored Provisional Research Plan is ready 2

Background Much HPWH research has been completed to date, reflecting the measure’s significance to the region (~300 aMW according to DRAFT 7 th Plan) Recent History: – Measure updated in November 2014 to include results of regional research – RTF thought additional research may be needed on a couple of additional parameters before “Proven” Set measure status to “Under Review” Sent RTF CAT to develop Research Plan investigating – HVAC interaction – Measure baseline 3

November 2014 RTF Decision “Update the savings, cost, and life for the HPWH UES measures as proposed and set the measure to Provisional category and Under Review status. Direct staff to develop research plan focused on: HVAC interaction factor, using a combination of a PNNL lab homes study and an engineering study, as proposed; and Determining baseline using data on existing tank size, sales data, and possibly survey data. Set the sunset date to 4/2015, at which time the RTF will review the research plan.” 4 Direction on data collection / analysis Research goals / objectives Looks similar to what we now call a “research strategy”

Research Strategies / Research Plan CAT sketched out, with more structure, research strategy based on the November RTF decision (shown in upcoming slides) CAT shared strategy with NEEA, who plans to sponsor the research CAT then drafted a full research plan (available on agenda) Draft research plan still being discussed, and once finalized will come before the R&E group 5

Research Strategy: HVAC Interaction, Part 1 (PNNL Lab Homes) Research Goal – Observe the space conditioning energy interaction that results from the installation of a HPWH in interior spaces Data Collection – PNNL Lab Home Study: Test four install locations throughout home Use 1kW space heaters and operate on a schedule similar to HPWHs 5-10 days per location Analysis – Compute change in space heating requirement and HVAC interaction factor for each location – Observe range of results; depending on range, results may be combined (averaged) if within a narrow band, or results could point to needing additional measure identifiers Estimated Cost Range: – ( $2M)

Research Strategy: HVAC Interaction, Part 2 (Engineering Study) Research Goal – Observe the space conditioning energy interaction that results from the installation of a HPWH in interior spaces Data Collection – None: Study will use existing data already collected from regional studies (Ecotope, NEEA, BPA, PNNL) Analysis – Hand calculations Balance heat flow in to HPWH zone from interior with heat flow to exterior and heat extracted by HPWH – Informed modeling Use a multi-zone heat transfer model Potentially integrate with whole-house simulations to test against Estimated Cost Range: – ( $2M)

HPWH Baseline: Context The challenge: – HPWHs represent a large efficiency resource for the region – HPWHs also represent the federal minimum for large tanks – Does this mean all large HPWHs have no savings? (No) – How can we determine whether a large HPWH purchase represents a resource or minimum compliance? What we need: – A model to determine the baseline (and savings) for HPWH purchases 8 “Essentially, all models are wrong, but some are useful.” - George E. P. Box

Market Small electric water heater (≤ 55 gal) Large electric water heater (> 55 gal) HPWHs: A Market Model 9 Purchaser A Purchaser B Choices -Small resistance water heater -Small HPWH -Large HPWH -Other (e.g. two small resistance tanks) Savings Potential? No Yes No How do we know which market someone is in? Proposed indicator: the existing tank being replaced Federal Min. Efficiency Electric resistance HPWH

HPWH Baseline: A Model (continued) 10 Key research questions: 1.How many people are in each market, i.e. how many customers are replacing small tanks versus large tanks? 2.What is the mix of tanks purchased by people in the small tank market? 3.What is the mix of tanks purchased by people in the large tank market? __%

HPWH Baseline: Two Approaches 11 ApproachData NeedsProsCons Full Market Survey Data -Survey data for entire electric water heater market, including information on existing tank and purchased tank -Provides full market view of baseline tanks -Less uncertainty than 2 nd approach - Expensive $$$ - Requires survey of program parts and non-parts Program and Sales Data -Program data including information on baseline (existing tank) and purchased tank -Sales data showing relative proportion of all electric water heater purchases (small ER, small HP, large ER, large HP) -Uses data that is simpler to collect (program participants, sales data) -Cheaper than 1 st approach -Still leads to reliable savings if we can show uncertainty is sufficiently small - Uncertainty may prove to be significant enough to require larger data collection (full market survey) CAT Recommendation

Proposed Motion “For the Residential Single Family and Manufactured Home HPWH measure, I _________ move the RTF: Accept the research strategy for the HVAC interaction parameter; Direct staff to further develop and report sensitivity findings on program and sales data baseline approach; Change the Category to Planning; Change the Status to Under Review; Set the sunset date to 10/30/2015.” 12

Additional Slides 13