SEEM Calibration: Phase IISingle Family Heating Energy

Regional Technical ForumAugust 20, 2013

Presented By: Josh Rushton and Adam HadleySubcommittee Review: August 6, 2013 ***

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975

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SEEM Calibration

Background: Phase I• Provided Calibrated T-stat

Settings for houses with known heating energy use– 30% of the 1404 RBSA homes were

used in calibration, the rest weren’t included because:• Incapable of running in SEEM

(foundation type, etc.)• Non-utility fuel use or equipment

(wood, oil, etc.)• Poor billing analysis results

– Note: Gas-heated homes were included in the calibration

• Approved May 2013 SF RBSA Pie: 1404 Homes

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552

Gas Heated, 249

Electric Heated, 180

In Utility Programs, but not in SEEM

calibration, 423

SEEM Calibration

Phase II• Purpose is to adjust for electric heating

energy in program-like homes.

• Adjustments need to address:– Non-utility heating sources;– Program-permitted gas heat sources (e.g., gas

fireplaces) – Other SEEM Calibration filters

• To capture effects on program-like homes, the present analysis is based on RBSA homes with: – At least one permanently-installed electric heat

source;– No gas, oil, etc. primary heating systems (FAF or

Boiler);– Note that heat stoves and fireplaces (any fuel)

are allowed.

• Status Update presented at June 2013 Meeting– Finish analysis and send to subcommittee

Single-Family RBSA Pie: 1404 Homes

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Subcommittee Meeting

• August 6, 2013– Presentation– Minutes– Draft Report

• Summary– Baylon: Recommendations to adjust the regression specification

for non-utility fuels; test climate zone’s effect.– Discussion on how to properly interpret the regression results

to determine off-grid and gas fuel use for different electric heating systems.

– Note while subcommittee was well-attended, Baylon, Hadley, and Rushton did 99% of the talking.

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Recent Changes• Added another variable to account for

differences in off-grid heating fuel usage between heating zone 1 and heating zones 2 and 3. This change improved the regression.

• Staff and Baylon revisited the subcommittee discussion regarding off-grid and gas fuel use. (See slides 10-12)

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Proposed Regression: Summary(Model fit to RBSA sites with permanently installed electric heating system and without non-electric central heating systems and with

Electric Heat > 0 kWh/yr)

ln (Elec tric Heat )     =𝐶0+𝐶1× ln (UA×HDD )+𝐶2× ln (Sq .  ft . )+𝐶3×IElec .FAF       +        

                      𝐶4×IHea t . pump  +       𝐶5×IO ff. grid . high    +    𝐶6×IOff. Grid .Med .Z1+  𝐶7×IGas . Heat . High    +  𝐶8×ISEEM .Bill          +    𝐶9×ISEEM .Data+𝜀

¿ ¿Variable Definition Coeff. Estimate Std. Error P-value

Intercept Intercept C0 0.031 0.85 0.971

Natural log of UA x HDD65 C1 0.364 0.07 0.000

Natural log of the area of conditioned floor space C2 0.487 0.09 0.000

Indicator: Has electric forced-air furnace C3 0.189 0.09 0.037

Indicator: Has heat pump C4 -0.400 0.07 0.000

Indicator: Non-utility fuel over 40,000 kBtu/yr C5 -0.532 0.09 0.000

Indicator: HZ1 and non-utility fuel between 5,000 and 40,000 kBtu/yr. C6 -0.169 0.07 0.018

Indicator: Gas heating energy over 5,000 kWh/yr C7 -1.05 0.12 0.000

Indicator: Failed SEEM Calibration billing analysis filter C8 -0.381 0.07 0.000

Indicator: Failed SEEM Calibration SEEM-input data filter C9 0.124 0.07 0.060

Adjusted R-squared: 0.316

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Determining Adjustments (“Typical”Program Screen)

Heating Zone 1

Coefficient Value

% Change in kWh

Number of

Homes

% of Homes

Adjustment Factor

(additive)C5 I.off.grid.high -0.532 -41% 45 9% -3.6%C6 I.off.grid.med.z1 -0.169 -16% 127 27% -3.9%C7 I.gas.heat.high -1.047 -65% 30 6% -3.8%C8 I.seem.bill -0.381 -32% 92 19% -5.7%C9 I.seem.data 0.124 13% 108 23% 2.8%n/a Zero kWh n/a -100% 24 5% -4.5%

Overall Adjustment Factor ==> 81.4%

Heating Zone 2 & 3

Coefficient Value

% Change

Number of

Homes

% of Homes

Adjustment Factor

(additive)C5 I.off.grid.high -0.532 -41% 32 29% -10.8%C6 I.off.grid.med.z1 -0.169 -16% 0 0% 0.0%C7 I.gas.heat.high -1.047 -65% 3 3% -1.6%C8 I.seem.bill -0.381 -32% 30 27% -7.8%C9 I.seem.data 0.124 13% 36 32% 3.9%n/a Zero kWh n/a -100% 17 13% -12.1%

Overall Adjustment Factor ==> 71.6%

Coefficient

Coefficient

-7.5%

-10.8%

Off-Grid Fuel Use FactorNatural Gas Use Factor

Electric Heating Energy Use Adjustment

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Estimating Electric Energy Use𝐴𝑛𝑛𝑢𝑎𝑙𝐸𝑛𝑒𝑟𝑔𝑦𝑈𝑠𝑒𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐=𝐻𝑡𝑔𝐸𝑛𝑒𝑟𝑔𝑦 𝑆𝐸𝐸𝑀×𝐸𝑛𝑒𝑟𝑔𝑦𝑈𝑠𝑒𝐴𝑑𝑗𝑢𝑠𝑡𝑚𝑒𝑛𝑡𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐

Variable Definition Units

Annual cost of off-grid fuel consumption. kWh/year

Estimate of annual heating energy consumption from calibrated SEEM run. kWh/year

Electric heating energy use adjustment from slide 7 (81.4 for HZ1; 71.6 for HZ2&3; for a “typical” program screen). %

Example (HZ1)

8000 kWh/year

81.4%

6509 kWh/year

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Estimating the Value of Off-Grid and Natural Gas Energy

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Given #1: Regression does not (nor can the data) tell us how a measure will affect the use of non-electric heating equipment.

• Ok. But Why?

• A: People.

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Given #2: Even if we assumed a 1 for 1 replacement of the Btu’s delivered, the relationship of electric heating energy consumption to cords of wood (or therms of

natural gas, or gallons of propane, or tons of pellets, etc.) has a wide range of possible values. Unknown fuel costs add to the uncertainty.

$0.00

$0.05

$0.10

$0.15

$0.20

$0.25

$0.30

Wood(stove,

fireplace)

Electric HP ElectricFAF

ElectricZonal

Propane(fireplace)

NaturalGas

(fireplace)

$/kW

h de

liver

ed to

the

room

Comparing Fuel Costs (Rough Numbers)Possible Range "Likely" Value

AssumptionsType Heating Effi ciencyWood 15 - 25 MMBtu/cord $125 - $225 per cord 20% - 60%E HP 130% - 220%E FAF 65% - 100%E ZonalPropane Btu/gal $2.25 - $2.75 per gal 50% - 80%Natural Gas Btu/therm $1.10 - $1.35 per therm 50% - 80%

- $0.094 per kWh

Cost

100%

Heat Content

n/a

91,690100,000

$0.084

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Conclusion

• Since the Regression does tell us the impact of off-grid and natural gas usage on electricity consumption, and

• Since we know the retail price of electricity fairly well,• We will use the retail price of electricity as a proxy for

the value of the off-grid and natural gas fuel.• We’ll assume changes in off-grid and natural gas usage

are proportional to changes in electric heating energy use.– While not perfect, remember we’re determining a cost input,

where less rigor is ok.

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Estimating the Value of Off-Grid Fuel Usage𝐴𝑛𝑛𝑢𝑎𝑙𝐹𝑢𝑒𝑙𝐶𝑜𝑠𝑡𝑂𝑓𝑓𝐺𝑟𝑖𝑑=𝐻𝑡𝑔𝐸𝑛𝑒𝑟𝑔𝑦𝑆𝐸𝐸𝑀×𝐹𝑢𝑒𝑙𝑈𝑠𝑒𝐹𝑎𝑐𝑡𝑜𝑟𝑂𝑓𝑓𝐺𝑟𝑖𝑑×𝐹𝑢𝑒𝑙𝑉𝑎𝑙𝑢𝑒𝑂𝑓𝑓𝐺𝑟𝑖𝑑

Variable Definition Units

Annual cost of off-grid fuel consumption. $/year

Estimate of annual heating energy consumption from calibrated SEEM run. kWh/year

Off-grid fuel use factor from slide 7 (7.5 for HZ1; 10.8 for HZ2&3; for a “typical” program screen). %

Cost of off-grid fuel is difficult to determine. Instead, we’re setting the value equal to the retail cost of electricity (average for the 4 PNW states according to EIA).

$/kWh

Example (HZ1)

8000 kWh/year

7.5%

$0.089/kWh

$53/year

Note: The same methodology will be used to determine the value of Natural Gas Fuel Usage (Using the natural gas fuel use factor from the regression). While it would seem beneficial to convert the electric kWh savings to therms, and enter therm savings into ProCost, the truth is that we don’t know exactly the mechanism for gas savings for any particular measure, so stating specific therm savings is unreliable.

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Baseline 8000 81.4% 6509 -7.5% $ 53.30 -3.8% $ 27.06 Effi cient 6500 81.4% 5288 -7.5% $ 43.31 -3.8% $ 21.99 Savings 1500 1220 $ 9.99 $ 5.07 Baseline 8000 71.6% 5727 -10.8% $ 77.11 -1.6% $ 11.38 Effi cient 6500 71.6% 4654 -10.8% $ 62.66 -1.6% $ 9.24 Savings 1500 1074 $ 14.46 $ 2.13

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2 or 3

Electric Heating Energy Use Adjustment

Annual Energy Use (kWh/yr)

Off-Grid Natural GasOff-Grid Fuel Use

Factor

Annual Fuel Use

Value

Natural Gas Use Factor

Annual Fuel Use

ValueCase

Heating Zone

Htg. Energy SEEM (kWh)

Electricity

Putting it all Together: Example Measure

ProCost Entry: Electric Savings

ProCost Entry: Fuel Cost Savings(O&M).

+Note: This example would apply to a “typical” program design, which requires primary electric heating system and screens out houses with any central non-electric space heating system.

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Other Program Screening Options

• A: Off-grid Fuel Screen– Houses do not have off-grid-fueled (wood, propane,

pellets, etc.) heating equipment • B: Gas Meter Screen– Houses do not have a natural gas meter.

• C: Electric Heat Signature Screen– House has a verified electric heat signature.

• The specification for this would need to be defined, likely as “passing” an RTF-approved calculator which uses 12 months billing history as the input (it would mimic PRISM, for example).

• Any combination of the three.

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Screen A – No Off-Grid AppliancesHeating Zone 1Screen A: No Off-grid AppliancesScreen Result < 5k >5k and < 40k > 40kPasses (277) 84% 13% 3% -3.4%Fails (199) 36% 44% 20% -15.1%% Change in kWh (slide 7) 0% -16% -41%

Heating Zone 2 and 3Screen A: No Off-grid Appliances Off-Grid Usage (kBtu/yr)Screen Result < 40k > 40kPasses (78) 92% 8% -3.2%Fails (43) 57% 43% -17.5%% Change in kWh (slide 7) 0% -41%

Average Factor (for reference)

-7.5%

Average Factor (for reference)

-10.8%

Off-Grid Usage (kBtu/yr) Off-Grid Fuel Factor

Off-Grid Fuel Factor

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Screen B – No Gas MeterHeating Zone 1Screen B: No Gas Meter NG Usage (kWh/yr)Screen Result < 5k > 5kPasses (411) 100% 0% 0.0%Fails (65) 51% 49% -32.0%% Change in kWh (slide 7) 0% -65%

Heating Zone 2 and 3Screen B: No Gas Meter NG Usage (kWh/yr)Screen Result < 5k > 5kPasses (141) 100% 0% 0.0%Fails (12) 58% 42% -27.1%% Change in kWh (slide 7) 0% -65%

-3.8%

Nat. Gas Fuel Factor

Average Factor (for reference)

-1.6%

Nat. Gas Fuel Factor

Average Factor (for reference)

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Screen C – Has Electric Heat SignatureHeating Zone 1Screen C: E. Heat Signature Electric Heating EnergyScreen Result 0 kWh > 0 kWhPasses (453) 0% 100% 0.0%Fails (23) 100% 0% -100.0%% Change in kWh (slide 7) -100% 0%

Heating Zone 2 and 3Screen C: E. Heat Signature Electric Heating EnergyScreen Result 0 kWh > 0 kWhPasses (135) 0% 100% 0.0%Fails (18) 100% 0% -100.0%% Change in kWh (slide 7) -100% 0%

E. Heat Sig. Factor

Average Factor (for reference)

-4.5%

E. Heat Sig. Factor

Average Factor (for reference)

-12.1%

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Examples –Program OptionsHeating Zone 1

Program Screen (in addition to the "typical" screen)

Screen Outcome

Electric Heating

Energy Use Adjustment

Off-Grid Fuel Use

Factor

Natural Gas Use Factor

Electric Heating Savings (kWh)

Off-Grid Fuel Cost Savings

Natural Gas Fuel Cost Savings

No Additional Screen n/a 81.4% 7.5% 3.8% 1220 9.99$ 5.07$ Passes 85.4% 3.4% 3.8% 1282 4.54$ 5.07$ Fails 73.7% 15% 3.8% 1106 20.16$ 5.07$ Passes 85.2% 7.5% 0% 1277 9.99$ -$ Fails 53.2% 7.5% 32% 797 9.99$ 42.72$ Passes 85.8% 7.5% 3.8% 1287 9.99$ 5.07$ Fails 0.0% 7.5% 3.8% 0 9.99$ 5.07$ Passes Both 89.2% 3.4% 0% 1339 4.54$ -$ Passes A, Fails B 57.2% 3.4% 32% 859 4.54$ 42.72$ Fails A, Passes B 77.5% 15% 0% 1163 20.16$ -$ Fails Both 45.5% 15% 32% 683 20.16$ 42.72$

Other Combinations….. ……

A: Off-grid Fuel Screen

B: Gas Meter Screen

C: Electric Heat Signature Screen

Combination: A & B

Example Measure: SEEM savings = 1500 kWh

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Discussion

• Primary Decisions– Does the RTF approve the proposed methodology to

determine calibrated heating energy use and savings?– Does the RTF approve the proposed methodology to

determine cost and savings for off-grid and natural gas fuels?• Other Questions

– Should the RTF post the savings for all of the program options identified (A, B, C, and combinations, pass/fail)?

– Does the RTF want to use the retail price of electricity as a proxy for the value of off-grid and natural gas fuels (for this specific situation)? $0.089/kWh?

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Decision

“I _______ move to adopt the Phase II SEEM Calibration for single family homes and the proposed analysis method for determining electric energy consumption, off-grid fuel cost, and natural gas fuel consumption.”

Note: This analysis applies to all single-family SEEM-affected UES measures, except those with their own calibration data (i.e. DHP’s).