electric “grid” savings and non-electric benefits for residential hvac-affected ues measures

Electric “Grid” Savingsand

Non-Electric Benefitsfor

Residential HVAC-affected UES Measures

Regional Technical ForumMarch 20, 2013

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Overview• For residential measures that effect heating and cooling usage:

– RTF electric savings estimates should be reliable from an electric utility planning perspective (i.e. “Grid Savings”).

• Measured Savings are considered reliable.– There appear to be non-electric benefits the RTF can account for in

its cost-effectiveness tests.• Measured Savings < Engineering Savings.

• Primary questions: – Is the following proposed framework for “Grid Savings” and NEB’s

correct?– How should RTF monetize non-electric benefits?

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Framework

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Engineering Savings (“The Whole Pie”)• Definition: Estimated electric energy savings based on physics (lower UA = lower heating energy use).

• Example: Engineering model assumes 100% electrically heated houses and “typical” usage.

Engineering Savings

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Measured Electric Sav-

ings

Components of Engineering Savings

Measured Electric Savings (a.k.a “Grid Savings”)• Definition: Electric energy savings for the population, measured through submetering or billing studies.

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Fuel Savings

Increased Com-

fort


Non-Electric Benefits

Non-Electric Benefits• Definition: Portion of the Engineering Savings that apply to the following two non-electric components:

• Fuel Savings (Non-electric)- Example: Occupant stops using their wood stove in the efficient-case, in favor of the electric heating system.- Example: Occupant continues using their wood stove, but uses less wood because of the lower house heat loss.

• Increased Comfort (a.k.a. “Takeback”)- Example: Occupants operate their house at a warmer (winter) and cooler (summer) temperature in the efficient-

case.

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Engineering Correction


Engineering Correction• Definition: Adjustment to engineering savings to account for non-typical usage.

• Example: Partial Occupancy; occupants are away for the winter months and leave t-stat at a very low setting.

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ings


Fuel Sav-ings

Increased Comfort



Not to Scale – These will vary by program, region, modeling method, etc. – Some slices of the pie could be zero (or negative).

𝐸𝑛𝑔𝑖𝑛𝑒𝑒𝑟𝑖𝑛𝑔𝑆𝑎𝑣𝑖𝑛𝑔𝑠=𝑀𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐 𝑆𝑎𝑣𝑖𝑛𝑔𝑠+𝑁𝑜𝑛𝐸𝑙𝑒𝑐𝑡𝑟𝑖𝑐 𝐵𝑒𝑛𝑒𝑓𝑖𝑡𝑠+𝐸𝑛𝑔𝑖𝑛𝑒𝑒𝑟𝑖𝑛𝑔𝐶𝑜𝑟𝑟𝑒𝑐𝑡𝑖𝑜𝑛

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Long-Term Effects• Non-Electric Fuel usage and “Comfort Level” varies depending on economic

conditions and other factors. – Billing analyses & metering studies are “snapshots in time”.

• For the same measure, the NEB’s could vary year-to-year.– Note how this could change Measured Electric Savings– Engineering Savings would see less change, if any.

Measured Electric Savings


Fuel Sav-ings

Increased Comfort

Strong Economy




Fuel Sav-ings

Increased Comfort

Weak Economy


We’re not likely to solve this issue today. Instead, since the data sources will vary, corrections for “long-term effects” will

need to be made on a measure-by-measure basis per RTF judgment.

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Uncertainty• Engineering Savings and Measured Electric Savings carry with them uncertainty

– If the uncertainty is large, it could (and should) call into question including Non-Electric Benefits. For Example:

Measured Electric Sav-ings


Lower-bound of Confidence Interval

Non-Elec-tric Bene-

fits


ings


Fuel Sav-ings

Increased Comfort

Upper-bound of Confidence In-terval

Non-Elec-tric Bene-

fits

We’re not likely to solve this issue today. Instead, since the data sources will vary, decisions on including Non-Electric Benefits will

need to be made on a measure-by-measure basis per RTF judgment.

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Examples• DHP• Weatherization

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ID Item Source/Method Heating Zone 1 Heating Zone 3

A Engineering Savings Metering Study 4000 4000



B Measured Electric Savings Billing Study All Sites 2300 300




C Measured Electric Savings + Non-electric Fuel Savings Billing Study Filtered for No

Supplemental Fuel 2900 2700






Non-electric Benefits

Fuel Savings C – B 600 2400






Non-electric Benefits

Fuel Savings C – B 600 2400

Increased Comfort A - C 1100 1300

Using DHP as an Example

Grid Savings (kWh)Non-Electric

Benefits(need to monetize)Notes: 1. All values in kWh/yr.

2. Values and method are for example only – we’ll discuss DHP measure specifics later.3. Engineering Correction is assumed to be 0 kWh/yr based on design of Metering Study to include randomly selected sites. Model

Correction


Model Correction

Fuel Savings

Increased Comfort



Fuel Savings

Fuel Savings

Increased Comfort

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ID Item Source/Method

A Engineering SavingsSEEM runs

calibrated to RBSA “post” t-stat setting; houses with “good” electric & gas bills only

T-stat: 68°F

pre & post

B Engineering Savings – Increased ComfortSEEM runs

calibrated to RBSA “pre” and “post” t-stat setting; houses with “good” electric & gas bills only

Tstat: 65°F pre68°F post

C Engineering Correction Rough estimate based on RBSA data% of houses with electric & gas heat only and with poor PRISM R-square

D NEB Fuel SavingsRough estimate based on 2 sources

i. RBSA: % of heat supplied by “other” fuels in electric heat homesii. DHP: % of fuel savings in the DHP measure

Measured Electric Savings B – C – D

Non Electric Benefits

Fuel Savings D




T-stat: 68°F

pre & post







T-stat: 68°F

pre & post








T-stat: 68°F

pre & post










T-stat: 68°F

pre & post








Non Electric Benefits

Fuel Savings D

Increased Comfort A – B




T-stat: 68°F

pre & post











T-stat: 68°F

pre & post

Using Weatherization as an Example

Note: This method is shown for illustration of the framework only; it has not been reviewed by the RTF and may not meet the RTF’s guidelines.


Model Correction

Fuel Savings

Model Correction

Fuel Savings


Increased Comfort

Fuel Savings


Model Correction

Fuel Savings

Increased Comfort

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Next Steps

• In both examples, Non-Electric Benefits are quantified in kWh’s.

• We need to then monetize the Non-Electric Benefits – (assuming they’re not zero)

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Fuel Savings

Increased Comfort



ProCost InputsData Set NameMeasure Index NameCosts must be denominated in the same year as 'Input Cost Reference Year' =2006

1 2 3 4 5 6 7 8Input Data

Category NameMeasure

NameSavings (kwh/yr) Life (yrs)

Capital Cost

Annual O&M

Shape Pointer

Non-E Val ($/yr)

Measure A Measure A 500 20 385$ 10$ ResDHWMeasure B Measure B 300 20 200$ (5)$ FLAT 15Measure C Measure C 150 20 35$ -$ ResDHW -5

ProCost Version: ProCost 2.3 - Build 257fRun Time: Friday, 16 March , 2012 at 12:55 PM

Data Source(s)

kWh/$ Conversi

on

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How to Monetize the Non-Electric benefits?• Option 1: Convert each Non-Electric Benefits into Dollars

– Non-Electric Fuel Savings• Convert kWh savings to cords of wood savings to dollar savings

– Issue: Many assumptions needed (Btu/cord; efficiency of stove, $/cord, pollution benefit, etc.)

– Increased Comfort• Value at the cost of electricity

– Occupant chose to pay for more electricity, so value of comfort should be at least equivalent to the price of electricity, if not more.

– Issue: Split between Increased Comfort and Non-Electric Fuel Savings is unknown.

• Option 2: Value both Non-Electric Benefits at the cost of electricity– Same logic as for Increased Comfort above– The “many assumptions” for converting kWh savings to cords of wood to dollar savings

would likely be “calibrated” to this value.• (Value of wood calibrated to be no lower than value of electricity.)

• Issue: Use Retail or Wholesale cost of electricity?– Guidelines specify avoided costs (wholesale).– Which is a better proxy for consumer economic value of

• non-electric fuel savings? • increased comfort?



Fuel Savings

Increased Comfort



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Decisions

1. Adopt the presented framework for quantifying Measured Electric Savings and NEB’s?– Current Framework

• NEB’s have not been (explicitly) included in the cost-effectiveness test.• Measured Electric Savings have sometimes included NEB’s.

– “Long-term” savings.

– Proposed Framework• Quantify Measured Electric Savings and NEB’s according to framework.

– Any decision to adjust values for “long-term effects” or uncertainty would be explicit and measure-specific.

• Include NEB’s in cost-effectiveness test.

2. How to Monetize NEB’s?– Which Option?

• Option 1: Convert each Non-Electric Benefits into Dollars (wood & electricity); or • Option 2: Value both Non-Electric Benefits at the cost of electricity

– Which value of electricity?• Retail?• Wholesale?

– Other Options



Fuel Savings

Increased Comfort



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Background Slides

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Related slides from the January 2014 RTF Meeting (“SEEM 94 Calibration to RBSA Data” Presentation)

electric “grid” savings and non-electric benefits for residential hvac-affected ues measures

Documents

electric energy savings

rtf electric savings

uncertaintyengineering

nonelectric components

electric heating system

nontypical usage

measure basis

rtf judgment