1. DHP Supplemental Fuel Screen Subcommittee Meeting Regional Technical Forum December 10, 2013

2. Today’s Agenda Subcommittee duties Motivation for screen Discuss candidate screens that have been proposed – Site visit screen – Bill screens (VBDD, “simple” monthly) Wrap up and next steps 2

3. Subcommittee Duties At its November meeting, the RTF voted to establish DHP Supplemental Fuel Screening Subcommittee Proposed duties for DHP Screening Subcommittee: 1.Identify workable screen(s) for all zones 2.Evaluate their implementation characteristics 3.Determine reliability of companion UES(s) for each screen 4.Make a recommendation to the full RTF Subcommittee should have at least (5) voting RTF members with expertise in programs, Zone 3, and DHP savings calibration 3

4. Motivation for Screen 4 VBDD screen results from previous analyses shown as an example.

5. Motivation for Screen 5 VBDD screen results from previous analyses shown as an example.

6. Site Visit Screen Description : – The home is either inspected by the utility or a contractor – If there is no heat source other than electric the home would qualify – If there is any other heat source, even if the owner says they don’t use it, the home would fail the screen – If home does not have a wood stove but still has a flue: Home would fail screen If homeowner chooses to remove the flue they would be considered full electric 6

7. Site Visit Screen (continued) Companion UES’s: – “Pass” screen (no supp. fuel) savings could be based on the self-reported “does not have supplemental fuel” survey group – “Fail” screen (has supp. fuel) savings could be based on the “does have supplemental fuel” group – Question: should these UES’s be Provisional and require further study? (see “Cons” on slide 24) 7

8. Site Visit Screen (continued) Pros: – Provides greatest potential for screened savings – Relatively easy to implement with contractor help. The contractor should be going to the home to provide a bid and therefore can provide the verification of heating systems (can also combine this with random inspections) – New homeowners can qualify with no previous usage history. – Rentals can be upgraded by the owner without having to have continuous renters with consistent usage numbers. 8

9. Site Visit Screen (continued) Cons: – Screen does not eliminate seasonally-occupied homes – We will miss homes that utilize secondary heat sources but still use enough electric heat to see successful savings of over ~3000 kWh/year – This program design may encourage some people to stop burning wood. If people know by removing their wood stove and flue, they qualify for the incentive, they will do so. We don't know what percentage of participants this will be, so we should study it. 9

10. Bill Screen 1 – VBDD Description: – The screen requires 12 months of utility bills prior to the DHP retrofit. There can be no change in occupancy within the 12-month billing history used for the screen. A variable-base degree day (VBDD) method is then used to assess the fit between outdoor air temperature and heating energy use, which is used to determine the existence of supplemental fuels. The following output values are required to pass the screen: R2 ≥0.6 Normalized, Annual Space Heating Estimate (SH) in kWh/yr – Heating Zone 1: SH ≥ 3,750 kWh/yr – Heating Zone 2: SH ≥ 7,500 kWh/yr – Heating Zone 3: SH ≥ 7,500 kWh/yr 10

11. Bill Screen 1 – VBDD (continued) Pros: – No site visit required – Minimal data required for screen (e.g. square footage or other home characteristics not needed) Cons: – 12-months of prior bills with no change in occupancy eliminates some potential program participants – Uncertainty in the screen’s ability to correctly identify supplemental fuel use requires some guesswork for NEBs 11

12. Bill Screen 1 – VBDD (continued) Companion UES’s: – The table below compares electric savings for those who pass the VBDD billing screen versus those who reported “no supplemental fuel use” in the occupant questionnaire 12 PASS Side Screened by Occupant Questionnaire Screened by VBDD Billing Analysis, R2 and min space heat % Difference Savings Heat Zone(kWh/yr) 1 2,780 2,7352% 2 1,911 1,942-2% 3 1,811 1,907-5% ALL 2,702 2,6661% Note: The occupant questionaire was part of the DHP pilot study and VBDD screen relies only on billing history

13. Bill Screen 1 – VBDD (continued) Companion UES’s (continued): – This table compares electric savings for those who fail the VBDD billing screen versus those who reported “supplemental fuel use” in the occupant questionnaire 13 FAIL Side Screened by Occupant Questionnaire Screened by VBDD Billing Analysis, R2 and min space heat % Difference Savings Heat Zone (kWh/yr) 1 (111) 625-118% 2 (305) (238)28% 3 (1,422) (959)48% ALL (242) 423-157% Note: The occupant questionaire was part of the DHP pilot study and VBDD screen relies only on billing history

14. Bill Screen 1 – VBDD (continued) 14 Match Rate Between Occupant Questionnaire and VBDD Screen Occupant No SuppOccupant Yes SuppMatch Rate Heat Zone VBDD NoVBDD YesVBDD NoVBDD YesNo SuppYes Supp 1 180749058554079%48% 2 9770348758%72% 3 5432406663%62% ALL 195859265969377%51% This table shows how frequently the VBDD screen and occupant questionnaire agreed or disagreed on the presence of supplemental fuel.

15. Bill Screen 1 – VBDD (continued) 15 Match Rate Between Occupant Questionnaire and VBDD Screen Occupant No SuppOccupant Yes SuppMatch Rate Heat Zone VBDD NoVBDD YesVBDD NoVBDD YesNo SuppYes Supp 1 180749058554079%48% 2 9770348758%72% 3 5432406663%62% ALL 195859265969377%51% This table shows how frequently the VBDD screen and occupant questionnaire agreed or disagreed on the presence of supplemental fuel.

16. Bill Screen 1 – VBDD (continued) 16 Can we design a “better” VBDD screen that gets electric savings right for both the pass and fail sides, and the supplemental fuel match correct? Match Rate Between Occupant Questionnaire and VBDD Screen Occupant No SuppOccupant Yes SuppMatch Rate Heat Zone VBDD NoVBDD YesVBDD NoVBDD YesNo SuppYes Supp 1 180749058554079%48% 2 9770348758%72% 3 5432406663%62% ALL 195859265969377%51% This table shows how frequently the VBDD screen and occupant questionnaire agreed or disagreed on the presence of supplemental fuel.

17. Bill Screen 1 – VBDD (continued) 17 A sensitivity analysis of the screen parameters suggests No

18. Bill Screen 1 – VBDD (continued) 18 A sensitivity analysis of the screen parameters suggests No As we increase the match rate for “yes, has supplemental fuel,” we decrease the match rate for “no supplemental fuel.”

19. Bill Screen 1 – VBDD (continued) 19 A sensitivity analysis of the screen parameters suggests No And vice versa.

20. Bill Screen 1 – VBDD (continued) 20 Similar results for Heating Zones 2 and 3 (HZ3 shown below)

21. Bill Screen 1 – VBDD (continued) Proposed option for this screen: – Set the “pass” and “fail” screen electric savings equal to their corresponding VBDD groups – Calculate total wood savings and distribute between the “pass” and “fail” groups based on match rate 21

22. Bill Screen 2 – Monthly Consumption Description: – This would require 12 months of continuous usage by the same occupant. – Determine baseline electric usage in the home (find 2 nd lowest monthly usage for the year and multiply by 12). – Add up the 12 months of usage and subtract the baseline. This would provide the kWh used for heating. – If this number is greater than 7500 kWh (for example), they would pass. 22

23. Bill Screen 2 – Monthly Consumption (continued) Pros: – Easy to implement for a utility and does not necessarily require a site visit – This would find all homes that have enough electric heat to save ~3000 kWh/year regardless of various heating sources. This can be very useful since there are many homes with old fuel oil systems that haven’t been used for years due to cost of oil but are still present since it costs to remove them. There are also many homes with fireplaces that are unused or minimally used that would offer excellent electric energy savings for DHP installs. – Offers black and white explanation to customers of why they qualify: you either have enough kWh to save or you don’t. 23

24. Bill Screen 2 – Monthly Consumption (continued) Cons : – New homeowners and rentals would not qualify. In addition, owners of second homes that have been seasonal would not qualify until they had lived here for one year rather than qualifying them as soon as they made the home their primary residence – Those wishing to “go off wood” would need to add usage to the grid for one year to prove their eligibility to save energy. – How do we eliminate or count out usage items like: water trough heaters, snow melt cable, water pipe heat tape, snow melt in drives and walks, space heat in barns/garages/well houses, which are not necessarily tied to space heat usage? 24

25. Bill Screen 2 – Monthly Consumption (continued) Cons (continued): – Some homes have electric resistance zonal heat in their bedrooms but not in the living area. They may pass this screen but upon install of the DHP may not see electrical energy savings due to configuration of the house. The DHP may only save on the wood use in the living/dining/kitchen area. – Program could provide positive reinforcement to the members who are most wasteful or have the most inefficient homes and penalizes smaller homes, weatherized homes, and homeowners who have an electrically conservative lifestyle. 25

26. Bill Screen 2 – Monthly Consumption (continued) Companion UES’s: – Would need to be calculated using a dataset similar to the annual dataset used for the VBDD screen. – We currently do not have the monthly data in hand to calculate the UES’s, though we could generate the dataset with a few full days of work (Ecotope estimate) – Staff would need clear direction from the subcommittee if we wanted to spend the time required to go down this path 26

27. Next Steps Is the group in favor of one or more of these screens? Would utilities want multiple screens? (e.g., site visit screen and bill screen) What about a hybrid screen? (e.g. site visit plus minimum consumption screen) 27