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SEEM Calibration: Phase II Single Family Heating Energy. Regional Technical Forum August 20, 2013. 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:
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SEEM Calibration: Phase IISingle Family Heating Energy Regional Technical Forum August 20, 2013
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
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
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.
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)
Proposed Regression: Summary(Model fit to RBSA sites with permanently installed electric heating system and without non-electric central heating systemsand with Electric Heat > 0 kWh/yr) Adjusted R-squared: 0.316
Determining Adjustments (“Typical”Program Screen) Off-Grid Fuel Use Factor Natural Gas Use Factor Electric Heating Energy Use Adjustment
Estimating Electric Energy Use 6509 kWh/year
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.
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.
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.
Estimating the Value of Off-Grid Fuel Usage $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.
Putting it all Together: Example Measure + ProCost Entry: Electric Savings 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. ProCost Entry: Fuel Cost Savings (O&M).
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.
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?
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).