1. Residential Showerheads UES Update Ryan Firestone Regional Technical Forum October 20, 2015

2. Measure Overview 2 Measure Developers RTF Staff/CAT Technical Subcommittee Review No Research & Evaluation Core Group Review No NotesResidential: Measure update to align with Thermostatic Shower Restriction Valve UES parameter values approved at July 2015 RTF meeting. Commercial: There is a separate Commercial Showerheads UES measure. No changes are being proposed to this measure. July 21, 2015 RTF decision: “Approve the Thermostatic Shower Restriction Valve UES measure and Research Strategy as presented: Set the category to ‘Planning’ Set the status to ‘Active’; Set the sunset date to July 31, 2018 and direct staff to update the parameter values in the Residential Showerhead UES measure to be consistent with the TSRV parameter values.” Today’s we’re only addressing updates to parameters consistent with the TSRV measure. More significant updates to the measure will be considered near the measure sunset date (6/2016)

3. Measure Overview Category: Proven Status: Active Sunset Date: June 30, 2016 Baseline: Current Practice Measure Description: Installation of a low-flow showerhead Measure Applications – Delivery mechanism: Retail, Mail-by-Request, Direct Install – Flow rate: 2.0, 1.75, and 1.5 gpm – DHW fuel: Electric, Gas, Any* – Showerhead use: Primary, Secondary, Any* *For Retail delivery mechanism, DHW fuel can only be “Any” and Showerhead use can only be “Any” 3

4. ParameterCurrentProposedSource Baseline showerhead flow rate (gpm)2.22.3 Current: Seattle City Light (2007) - In situ measurement of existing showerheads Proposed: RBSA (2011) - In situ measured flow rate Shower duration (minutes)7.848.06 Current: "Seattle Home Water Conservation Study. The Impacts of High Efficiency Plumbing Fixture Retrofits in Single-Family Homes". For Seattle Public Utilities and the U.S. EPA. Prepared by: Peter W. Mayer, William B. DeOreo, David M. Lewis of Aquacraft, Inc. (December 2000) Proposed: LBNL metered data from San Francisco Bay Area used for Thermostatic Shower Restriction Valve measure (2013) - this dataset was needed to look at time-varying shower temperature signature Showers per person per year193250 Current: Seattle City Lights, 1993 Proposed: Residential End Uses of Water Study (1999) and EPA New Homes study (2011) Annual usage (showers/showerhead) - Any showerhead 404328 Current: "Seattle Home Water Conservation Study. The Impacts of High Efficiency Plumbing Fixture Retrofits in Single-Family Homes". For Seattle Public Utilities and the U.S. EPA. Prepared by: Peter W. Mayer, William B. DeOreo, David M. Lewis of Aquacraft, Inc. (December 2000) Proposed: RBSA counts of showerheads and residences Annual usage (showers/showerhead) - Primary showerhead 483373 Maintained same ratio of primary to secondary usage Annual usage (showers/showerhead) - Secondary showerhead 246186 Percentate of showerheads that are Primary67%59% Current: Implicit in results Proposed: RBSA Electric efficiency98%100% Current: Only considered electric resistance water heaters, not HPWH. Proposed: Small market share of HPWH bumps up efficiency slightly. % Electric DHW64%62% Current: 6th Plan assumptions Proposed: RBSA Water/wast water costs ($/1000 gallons)$10.03$13.20 Current: Assumptions used in 6th Plan Proposed: Assumptions used in (draft) 7th Plan Water/wast water embedded energy (kWh/1000 gallons) 5.303.68 Updated Parameter Values 4 Most significant changes

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8. Cost, Lifetime, and Cost Effectiveness 8 Cost: No proposed changes – Retail: $24 – Mail-by-request: $24 – Direct install: $31 More thorough measure update at sunset date (June 2016) should include cost update Lifetime: No proposed change – 10 years Cost effectiveness: All measure applications remain cost effective

9. Proposed Motion “Approve the updates to the Residential Showerhead UES measure as presented. Keep the category at ‘Proven’ Keep the status at ‘Active’ Keep the sunset date at June 30, 2016” 9