Analysis of Cost and Savings Values for Revised Energy Star Dishwasher Specifications

1. Analysis of Cost and Savings Values for Revised Energy Star Dishwasher Specifications June 6, 2006 Revised August 8, 2006 Revised Again January 23, 2007

2. Outstanding Issues from August Meeting Issue 1 – Allocation of efficiency improvement between water use and machine energy Revised analysis uses recently released DOE assumptions regarding allocation of savings – RTF decision needed Issue 2 – Retail Incremental Cost of EF65 (and above) Dishwashers Revised analysis uses recently released DOE analysis - RTF decision needed Issue 3 – Projected Sales Weighted Average EF of Energy Star models Revised analysis uses 2005 Oregon Tax Credit distribution, rather than 2004-2005 distribution – RTF decision needed

3. Refresher: 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

4. Reduced Hot Water Use Increases Energy Factor – but it’s not the only way

5. US DOE Assumes Hot Water Use per Cycle Very Similar to RTF “Curve fit”

6. However --- DOE Assumes Average Temperature Rise is 70 F RTF Assumed 90 F This increases the proportion of electricity energy used by the dishwasher

7. . . . And decreases the proportion of electricity energy used by the hot water heater

8. Savings Assuming DOE Water Use and 70 F Temperature Rise

9. Savings Assuming DOE Water Use and 90 F Temperature Rise

10. Cost-Effectiveness Assuming DOE Incremental Prices, Water Use and 70 F or 90 F Temperature Rise

11. So What Should We Assume About the Allocation of Efficiency? • Staff Proposal: • Use DOE estimate of hot water use • Avoids tying savings to current model’s design features • Consistent with federal standards setting assumptions • Use DOE estimate of 70 F temperature rise • Consistent with federal standards setting assumptions • Consistent with Energy Guide labeling assumptions

12. DOE Dishwasher Retail Price Assumptions

13. Retail Price vs. Efficiency Relationship for Oregon Tax Credit Data - 2005

14. Total Retail Price Estimates for DOE and RTF “Curve Fit”* *EF 1.11 models excluded from analysis

15. Incremental Retail Price Estimates for DOE and RTF “Curve Fit”* *EF 1.11 models excluded from analysis

16. So What Should We Assume for Incremental Cost of Energy Star Dishwashers? • Staff Proposal - Use DOE Retail Price Assumptions • Incremental Price of EF65 over EF58 = $21 (2005$) • Alternative – Use 2nd order polynomial curve fit to average retail price vs. efficiency data • Incremental Price of EF65 over EF58 = $87 (2005$)

17. Post-2007 Projected Efficiency Mix Based on Oregon Tax Credit Data Projected Sales Weighted Efficiency for Energy Star Dishwashers Using Either Data Set = EF67 and does not change TRC cost-effectivenesss