Ductless Heat Pumps (DHP) in Single Family Homes with Zonal Electric Heat UES Measure Update Regional Technical Forum March 18, 2014.

Ductless Heat Pumps (DHP)in Single Family Homes with Zonal Electric Heat

UES Measure Update

Regional Technical ForumMarch 18, 2014

2

Today’s Agenda

• Measure Overview• Staff Highlighted Areas• DHP Recap• Unscreened UES– Recent decisions affecting DHP– Staff Recommendation & Proposed Decision

• Screened UES– Presentation of two DHP screens– Staff/Subcommittee Recommendation & Proposed

Decision

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DHP Measure Overview

• Current Category: Proven

• Current Status: Under Review

• Current Sunset Date: March 31, 2014

• Reason for Update/Review: Measure was put “Under Review” and given a short sunset date by the RTF

in November 2013. The RTF asked staff to come back in March 2014 with:

- Updated savings, including measure interactions using ‘Option 3;’- A supplemental fuel screen proposal brought forth by subcommittee; and- A DHP-specific loadshape.

http://rtf.nwcouncil.org/measures/measure.asp?id=131

http://rtf.nwcouncil.org/meetings/2013/10/Last%20Measure%20In%20Proposal_v5.pptx

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Staff Highlighted Areas• Recent RTF decisions on measure interactions and SEEM

calibration– Key question: Do we “open up” the unscreened DHP workbook

for measure interactions and calibration, or do we keep the current LMI assumption and calibration - and extend the sunset date?• Staff recommendation: Keep current calibration and LMI assumptions

and extend the sunset date for a period of three years. If staff finds that calibration and/or measure interactions significantly change savings, bring the measure back at anytime before then.

• Screened UES’s– Key question: What do we do about the screened UES’s

proposed by the subcommittee?• Staff recommendation: Accept the Median Low Bill screen measure

for Heating Zone 3, and pursue an “All Electric” screen measure.

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DHP Recap• At the October 2013 meeting,– Screened and unscreened (for supplemental fuel)

measures were presented– RTF members did not reach consensus on a screened

(VBDD) or unscreened UES– Members voted to table DHP until November

• At the November 2013 meeting,– Staff presented an unscreened UES measure, which passed– RTF members directed staff to 1) form a DHP Supplemental

Fuel Screening Subcommittee, and 2) come back in March 2014 with resolution on measure interactions (i.e. “Option 3”)

http://rtf.nwcouncil.org/meetings/2013/10/

http://rtf.nwcouncil.org/meetings/2013/11/Default.asp

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Recent RTF Decisions Affecting DHP

• Measure interactions– Last month, RTF voted to adopt new measure

interaction language for guidelines– Effectively over-ruled previous “Option 3” decision

• SEEM Calibration– In December, RTF voted to use continous U0-based

adjustments for SEEM calibration– If we want to look at measure interaction

sensitivities for DHP, a U0-based calibration would be preferable to the current DHP calibration

http://rtf.nwcouncil.org/meetings/2014/02/

http://rtf.nwcouncil.org/meetings/2013/12/Default.asp

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Unscreened UES

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Status of Outstanding Issues

• Calibration– Ecotope completed a draft DHP calibration based

on U0, which is being reviewed by staff

• Measure interactions– Once calibration is set, staff can conduct a

measure interaction sensitivity analysis similar to the one presented in February

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Status of Outstanding Issues (continued)

• Loadshape– Ecotope has provided several DHP loadshapes,

both for heating and cooling– Staff in the process of reviewing loadshapes and

integrating them into ProCost

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Staff Recommendation

• Staff sees two possible paths forward for the current unscreened UES measure:– Update the DHP with the new calibration, measure

interactions, and loadshape as soon as they are ready; extend the current sunset date to a point when we think the work could be completed (e.g. “check-in” point)

– Keep the DHP measure as-is and extend the sunset date for three years. Staff will investigate the impact of the new calibration/measure interactions and bring the measure back to the full RTF if changes in measure savings are significant.

• Staff recommends the second path.

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Proposed Decision

“I _______________ move that the RTF:

• Extend the sunset date for the unscreened Ductless Heat Pumps for Zonal Electrically-Heated Single Family Homes measure to August 31, 2014, at which point the RTF can check in on updates made to the measure calibration, measure interactions, and loadshape.

OR• Extend the sunset date for the unscreened Ductless Heat

Pumps for Zonal Electrically-Heated Single Family Homes measure to March 31, 2017;– keep the category as ‘Proven’ and set the status to ‘Active’;

– direct staff to investigate the impact of updates to the calibration, measure interaction, and loadshape, and to bring the measure back to the full RTF anytime before the sunset date if the updates cause significant changes in savings.”

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Screened UES

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DHP Screening

• DHP Supplemental Fuel Screening Subcommittee met twice since its formation in November of 2013

• Meeting materials can be found on the subcommittee webpage here

• Subcommittee has brought two screens forward:– Median Low Bill (MLB) screen– All Electric Home screen

http://rtf.nwcouncil.org/subcommittees/DHPScreen/Meetings/meetings.htm

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The Median Low Bill (MLB) Screen• What is it?– A ‘simple’ monthly bill screen that can be used to separate

heating from non-heating energy consumption

– Requires twelve months of consecutive bills

– Screen looks at the three lowest bills of the year, and picks the middle of the three – this is the median low bill

– The median low bill is used to estimate the non-heating base load of the building

– For the nine (9) remaining months, the median low bill is subtracted from each month, leaving the estimated monthly heating energy consumption

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The MLB Screen (continued)– The estimated heating energy for the nine months is

summed, giving total annual estimated heating energy

– This total is the compared against a screen threshold• If a home uses more heating energy than the screen threshold, it

PASSES;

• If a home uses less heating energy than the threshold, it FAILS.

– The following are suggested thresholds in the current analysis:• Heating Zone 1: 5,000 kWh

• Heating Zones 2 and 3: 9,500 kWh

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The MLB Screen (continued)

• Staff insights on MLB screen results– Screen “passes” some homes with supplemental fuel and

“fails” some homes without (and vice versa)• The screen’s main purpose is to find minimum electric savings,

not necessarily presence of supplemental fuel• As a result, wood savings show up on both sides of the screen

– As it stands, screen has little to no benefit for HZs 1 and 2– Screened savings for HZ3 (~1300 kWh) are still far below

a “no supplemental fuel” savings (~3000 kWh); however, MLB-screened savings are four times the current unscreened savings (~300 kWh) for zone 3

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MLB Screen (continued)

– MLB screened savings are based on actual DHP pilot population while unscreened savings are based on the more “general” RBSA population• Unscreened savings were generalized to the RBSA

population as this was thought to be more representative of a potential program participant• For MLB-screened savings, it is analytically infeasible to

generalize to the RBSA population

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MLB Screen Savings

CZ1 CZ2 CZ3 CZ1 CZ2 CZ3 CZ1 CZ2 CZ3HZ1 HZ2 HZ3

-

500

1,000

1,500

2,000

2,500

3,000

3,500 Savings kWh/yr

Unscreened

Climate

kWh/

yr

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MLB Screen Savings


-

500

1,000

1,500

2,000

2,500

3,000


Unscreened

MLB Screen, PASS

Climate

kWh/

yr

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MLB Screen Savings


-

500

1,000

1,500

2,000

2,500

3,000


Unscreened

MLB Screen, PASS

MLB Screen, FAIL

Climate

kWh/

yr

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Review Workbook

• Open analysis workbook to show screened savings using the MLB screen

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All Electric Home 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

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All Electric Home Screen (continued)

• Companion UES’s: – “Pass” screen savings could be based on the self-

reported “does not have supplemental fuel” survey group (~3000 kWh)

– “Fail” screen savings could be based on the “does have supplemental fuel” group (~ -800 kWh)

– Note: if we would want to use a ‘tiered’ screen in combination with the MLB screen we would have to recalculate the MLB screen savings (i.e. the same program could not run an MLB screen and All Electric Home screen as they are currently defined).

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All-Electric Home Screen (continued)

• Pro:– Provides greatest potential for screened savings per

site• Con:– 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 may do so. We don't know what percentage of participants this will be, so we should study it.

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All-Electric Home Screen (continued)

• Possible Research Study– Although all electric homes in HZ3 represent a

relatively small population, the potential savings are not trivial (~5 aMW)

– However, small population means sample sizes for research are also small; therefore, possible research questions are restricted

– A small sample (e.g. 100 sites) could indicate whether this issue is a relatively large effect (e.g. real savings are less than 1000 kWh and not 3000 kWh)

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All-Electric Home Screen Savings


(1,000)

(500)

-

500

1,000

1,500

2,000

2,500

3,000

3,500


Unscreened

Climate

kWh/

yr

27



(1,000)

(500)

-

500

1,000

1,500

2,000

2,500

3,000

3,500


Unscreened

MLB Screen, PASS

Climate

kWh/

yr

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(1,000)

(500)

-

500

1,000

1,500

2,000

2,500

3,000

3,500


Unscreened

MLB Screen, PASS

All Electric Screen, PASS

Climate

kWh/

yr

*

* Green bar (“PASS”) represents All Electric screen savings if there is no program-induced fuel switching.

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(1,000)

(500)

-

500

1,000

1,500

2,000

2,500

3,000

3,500


Unscreened

MLB Screen, PASS

All Electric Screen, PASS

All Electric Screen, FAIL

Climate

kWh/

yr

*

* Green bar (“PASS”) represents All Electric screen savings if there is no program-induced fuel switching.

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Staff Recommendation

• Approve MLB screen for Heating Zone 3 only, and set its sunset date equal to that of the unscreened UES

• Develop research plan to study effect of All Electric Home screen; bring back as a Provisional UES measure

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Proposed Decision“I _______________ move that the RTF:

• Approve the Median Low Bill screen UES values for Heating Zone 3 as a Proven UES,– set the measure status equal to that of the unscreened UES,

– and set the sunset date to March 31, 2017.

• Decide (to pursue / not to pursue) an All-Electric Home screen;

• (If screen is pursued), either:– Develop research plan to study effect of All Electric Home screen,

OR

– Approve the All Electric Home screen UES values for Heating Zones 1,2, and 3 as a Proven UES using the LMI assumptions of the unscreened UES;• set the measure status to “Under Review”; and

• and set the sunset date to March 31, 2017.

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Appendix

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The MLB Screen: UES ExplainedPotential Heating Zone 3 Participants (n=169)

MLB

PASS (50%)

FAIL (50%)

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MLB

PASS (50%)

FAIL (50%)

YES Supp. Fuel(43%)

NO Supp. Fuel(57%)

YES Supp. Fuel(74%)

NO Supp. Fuel(26%)

35


MLB

PASS (50%)

FAIL (50%)

YES Supp. Fuel(43%)

NO Supp. Fuel(57%)

YES Supp. Fuel(74%)

NO Supp. Fuel(26%)

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The MLB Screen: UES Explained

PASS (50%)

YES Supp. Fuel(43%)

NO Supp. Fuel(57%)

37


PASS (50%)

YES Supp. Fuel(43%)

NO Supp. Fuel(57%)

DHP Field Study Results for HZ3:EUI no supp fuel: 0.977 kWh/yr/ft²EUI with supp fuel: -0.271 kWh/yr/ft²

No supp fuel ann savings: 2,961 kWh

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PASS (50%)

YES Supp. Fuel(43%)

NO Supp. Fuel(57%)



(43% x -0.271 + 57% x 0.977) / 0.977= 45% (this is percent of no supp fuel savings)

UES = 45% x 2,961 kWh = 1,339 kWh

NEBs = (2,961 kWh – 1,339 kWh) x $0.82/kWh = $132/yr

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MLB

PASS (50%)

FAIL (50%)

YES Supp. Fuel(43%)

NO Supp. Fuel(57%)

YES Supp. Fuel(74%)

NO Supp. Fuel(26%)

40


FAIL (50%)

YES Supp. Fuel(74%)

NO Supp. Fuel(26%)

41


FAIL (50%)

YES Supp. Fuel(74%)

NO Supp. Fuel(26%)



42


FAIL (50%)

YES Supp. Fuel(74%)

NO Supp. Fuel(26%)



(74% x -0.271 + 26% x 0.977) / 0.977= 5% (this is percent of no supp fuel savings)

UES = 5% x 2,961 kWh = 157 kWh

NEBs = (2,961 kWh – 157 kWh) x $0.82/kWh = $229/yr

Ductless Heat Pumps (DHP) in Single Family Homes with Zonal Electric Heat UES Measure Update Regional Technical Forum March 18, 2014.

Documents

current unscreened ues

electric screen measure

current calibration

draft dhp calibration

dhp loadshapes

table dhp

dhp recapat

unscreened dhp workbook