1 Analysis of Cost and Savings Values for Revised Energy Star Dishwasher Specifications June 6, 2006

2 Issue Summary EPACT 2005 required EPA to update minimum Efficiency Requirements for Energy Star Dishwashers –Existing = EF- 58 –New = EF- 65 –New Requirements Effective – January 1, 2007 Existing deemed savings and cost based on EF – 52 baseline

3 Analytical Approach Data Source – Retail Price –Oregon Residential Tax Credit Data for 2004 & 2005 Retail Prices paid - (including “in store” rebates/discounts) EF (cycles/kWh) Water Factor (gals/cycle) –Energy Star data on qualifying models Data Source – Energy Savings –Use DOE Test Procedure –Use FTC Energy Guide Model Listings to Estimate Base Case

4 Oregon Residential Energy Tax Credit Data 2004 Tax Year Retail Price data on 10,199 units Minimum EF – 58 Some units have water factor data 2005 Tax Year Retail Price Data on 6,924 units Minimum EF – 62 All units have water factor data

5 DOE Test Procedure Defines 215 cycles/year as “average use” Requires test of machine with and without “soil sensor” controls Weights test results by fraction of time consumer adopts sensor controls –5% Heavy sensor use –33% Medium sensor use –62% Light sensor use

6 Proposed Savings Assumptions Energy Use Base Case FTC Energy Guide Label for 2004 “average” = 371 kWh/yr = EF 58 Energy Star Use = 331 kWh/yr = EF 65 Savings = 40 kWh/yr (w/electric water heating)

7 Consolidated Retail Price Data from Oregon Tax Credit Data Base

8 Retail Price vs Energy Efficiency

9 Average Retail Price vs Energy Efficiency

10 Minimum Retail Price vs Energy Efficiency

Is There Really An Incremental Retail Cost?

12 So What Should We Assume for Incremental Cost of EF 65 vs EF 58 Alt 1 - Use 3 rd order polynomial curve fit to minimum retail price vs efficiency data  Incremental Price = $25 (2005$) Alt 2 – Use 3 rd order polynomial curve fit to average retail price vs efficiency data  Incremental Price = $201 (2005$) Alt 3 – Use Average Difference in Retail Price  EF 58 Retail Price is $132 more than EF 65 Alt 4 – Use Minimum Difference in Retail Price  EF58 Retail Price is $34 more than EF 65

13 Allocation of Savings For Dishwashers using water heated with electricity Dishwasher EF = cycles/kWh –1/EF = kWh/cycle e.g., 215 cycles/year / 371 kWh/yr = EF 58 Machines with the same EF can have differing shares of water use and “machine” (i.e., motor, pump, drying) electricity use –This means lowering hot water is not the only way to increase electricity savings

14 Reduced Hot Water Use Increases Energy Factor

...But May Not Reduce Electricity Use for Dishwashers Using Gas Water Heating Energy Factor Machine Energy Use (kWh/cycle) Hot Water Use - Electric DHW (kWh/cycle) Hot Water Use - Gas DHW (MMBtu/cycle) Hot Water Use (gals/cycle) Total Electricity Use w/Electric DHW (kWh/cycle) Total Electricity Use w/Gas DHW (kWh/cycle) kWh Savings/cycle - Electric DHW kWh Savings/cycle - Gas DHW MMBtu Savings/cycle - Gas DHW

16 So What Should We Assume About the Allocation of Efficiency Only hot water use reduction –OR Tax Credit Data shows EF 65 uses 6.04 gal cycle vs 8.2 for the EF models Assume motor and pump use declines in same proportion as hot water use –50/50 split in energy reduction eliminates negative electricity savings for dishwashers supplied by gas water heaters –Problem: No data to support this

17 Proposal No statistical evidence to support retail price difference (EF 64 – EF 67 appears to be a “sweet spot”) –Use curve fit to minimum cost – EF58>EF65 = $25 –Test sensitivity of B/C Ratio with $0 incremental cost Data suggest that hot water reduction is primary method of achieving higher EF (e.g., “sensor controlled” wash) –Use average water use data from actual models in OR Tax Credit Data Base EF 58 = 8.2 gal/cycle EF 65 = 6.04 gal/cycle

Results Assuming EF 65 Incremental Cost of $25 MeasureIncremental Cost Total Electricity Savings (kWh/yr) Gas Savings (Therms/yr) Water Savings (gals/yr) TRC B/C Ratio EF65 - Electric Water Heater$ EF65 - Gas Water Heater$ EF68 - Electric Water Heater$ EF65 - Any Water Heater$ EF68 - Any Water Heater$ EF93 - Electric Water Heater$ , Any EF - Any Water Heater$ EF68 - Gas Water Heater$ EF93 - Any Water Heater$ , EF93 - Gas Water Heater$ ,

Results Assuming EF 65 Incremental Cost of $0 MeasureIncremental Cost Total Electricity Savings (kWh/yr) Gas Savings (Therms/yr) Water Savings (gals/yr) TRC B/C Ratio EF65 - Electric Water Heater$ EF65 - Any Water Heater$ EF65 - Gas Water Heater$ EF68 - Electric Water Heater$ EF68 - Any Water Heater$ EF93 - Electric Water Heater$ , Any EF - Any Water Heater$ EF68 - Gas Water Heater$ EF93 - Any Water Heater$ , EF93 - Gas Water Heater$ ,

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