Determining the “Last-in case” for Single Family HVAC and Weatherization UES Measures

1. Determining the “Last-in case” for Single Family HVAC and Weatherization UES Measures Regional Technical Forum September 17, 2013

2. Goal for Today • Staff would like to check with the RTF on: • Including heating system in the last-measure-in analysis (as proposed). • Assuming 85% of the cost-effective measures get implemented by the end of the measures’ EUL. • Methodology.

3. Background • Currently, the “Last-in case” is set at: • These are approximately the cost-effective limits, according to the 6th Plan.

4. Guidelines “The UES for each measure should be computed under the assumption that all othermeasures it significantly interacts with are already implemented… The other measures assumed to be present should be consistent with expected typical conditions at the end of the measure’s effective useful life.” Savings, Section 2.3.3.4. Interactions between Measures

5. Proposal • Determine the “Last-in case” by applying 85% of the cost-effective measures to the applicable RBSA homes.

6. Example of Applying 85% to RBSA– Attic Insulation Assumption: It’s cost-effective to insulate to R-38 where existing insulation is R-15 or less.

7. Determining Cost-Effective Measures • The “cost-effective insulation levels” and “cost-effective starting point limits”: • Require an iterative process to determine, since they • Are dependent on heating efficiency and the insulation levels/limits.

8. Methodology – In Detail After all are “yes”, “average R-value” = “Last-in case” definition.

9. Preliminary Analysis Results

10. Lower Shell/Component Efficiencies in exchange for Higher Heating System Efficiency In the current UES, heating system wasn’t a part of the “Last-in case”. Instead, the measure definition depends on the heating system type in the house. There is an “average heating system” case – its make-up is shown here for comparison. • The Proposed “Last-in Case” is much less efficient than the Existing “Last-in Case”. This is because: • Heat pumps now make up most of the “Last-in case”; • 15% of cost-effective measures won’t be implemented; and • Many houses fall under the cost-effective insulation level, but not far enough to justify a measure (i.e. R-19 to R-30 attics).

11. How the “Last-in Case” will be used

12. Discussion • Staff would like to check with the RTF on: • Including heating system in the last-measure-in analysis (as proposed). • Assuming 85% of the cost-effective measures get implemented by the end of the measures’ EUL. • Methodology. • These assumptions seem appropriate to staff… • However, they causes results that are contrary to 30 years of EE direction • Example: insulating floors may no longer be a cost-effective measure; or insulating attics from R-19.

13. Extra Slides

14. Reminder on Measure Bundling • Non-cost-effective measures could be bundled with cost-effective ones to get a cost-effective “package”. • Allows deeper savings • Allows cost synergies • Allows program flexibility Note: The values given are for illustration only.

15. Methodology – Choosing a Starting Point • Choose a starting point of efficiency of all Last-Measure-In parameters. • Re-compute the starting point to understand the effect of 85 % market penetration.

16. Methodology – Target Parameter • Choose target parameter (e.g. Attic insulation). • Keep all other parameters at 85-15 chosen efficiency level. • Vary parameter property (R-value) to understand cost effective limits of that parameter. • Repeat for all Last-Measure-In parameters.

17. Methodology – Iterate to Converge • Once all chosen parameter values have been determined, construct a house with chosen parameters at 85% penetration. • Re-simulate parameter cost effectiveness limits on this house through convergence.