SEEM Calibration: Phase-2 Adjustments for Failed VBDD Fits Regional Technical Forum August 12, 2014

Calibration Review Phase I: Estimating total heating energy. – Align SEEM with billing data for homes with strong and clear heating energy signatures and no off-grid fuels. Phase II: Estimating electric heating energy in “typical” program homes. – How is electric heating energy affected by the presence of natural gas and off-grid fuels? – What can we say about electric heating energy in homes with weak or unclear heating energy signatures? 2

Today’s business Current SF calibration and initially proposed MH calibration indicate about 30% lower heating energy for homes with “poor” VBDD fits. Subcommittee recommendation reduces this to 14%. About 25% of RBSA homes have poor VBDD fits. This alters a downward adjustment to VBDD-derived heating energy estimates o About 6% to 7% net adjustment with existing 30% figure; o About 3.5% net adjustment with recommended 14% figure. Adjustment applies to base-case, efficient-case, and savings.

Subcommittee Meetings July 18, 2014 – What can we say when VBDD fails – Minutes Minutes – Presentation Presentation August 1, 2014 – What should we do when VBDD fails: Two options – Minutes Minutes – Presentation Presentation

Annualized energy All else equal, homes caught by poor-VBDD filter have lower annualized energy values. Regression model (accounts for UA*HDD, square footage, etc.) estimates around 2800 kWh lower kWh is about 14% of average total energy; Regression presented to subcommittee was based on SF homes. Similar regression with manufactured homes also gave 14%.

Annualized kWh on our main question Annualized energy data say that “poor-VBDD” homes have 2800 kWh less than “good-VBDD” homes. How is the missing 2800 kWh distributed across end-uses? Subcommittee discussed two options Mostly missing heating energy? From all end-uses equally? Again, the difference to savings is only about 3.5%. Subcommittee Recommendation

Reasoning We don’t really know what’s happening with a lot of the poor-VBDD cases (and we’re only talking about a 3.5% difference). A “middle-of-the-road” solution is to assume those sites act similarly to good-VBDD sites with respect to unobservable features. In particular, it makes sense to assume the fraction of total energy that goes to heating is the same in poor-VBDD homes and good-VBDD homes.

SF Calibration, Phase II (step 1) Good-VBDD homesPoor-VBDD homes All Zones Adjustment for affected homes Percent of homes affected Net adjustment Percent of homes affected Net adjustment Off-grid high -39% 9% 4% 31% 12% Off-grid med, Z1 -20% 25% 5% 25% 5% Gas heat high -69% 7% 5% 3% Poor-VBDD 13.4% 20.4% Conclusion: Non-electric fuels account for some of the 14% gap between good-VBDD and poor-VBDD homes. How much: 20.4 – 13.4 = 7.0 percentage points. This leaves 14.0 – 7.0 = 7.0 percentage points that are due to other aspects of the poor-VBDD filter. Poor VBDD 0% 100% 7% Final group adjustment: 13.4% 27.4% 7.0%

SF Calibration, Phase II (step 2) Zone 1 Adjustment for affected homes Percent of homes affected Net additive adjustment (PROPOSED) Net adjustment with 28% poor- VBDD figure Net additive adjustment (CURRENT) Off-grid high-39%11%4.3% 4.2% Off-grid med (Z1)-20%30%6.2% 5.2% Gas heat high-69%8%5.2% 4.3% Poor VBDD-7%22%1.6%4.7%6.3% Zero kWh-100%5%NA 5.3% Total 17.2%20.3%25.2% Zones 2-3 Adjustment for affected homes Percent of homes affected Net additive adjustment (PROPOSED) Net adjustment with 28% poor- VBDD figure Net additive adjustment (CURRENT) Off-grid high -39%27%10.7% 10.4% Gas heat high -69%2%1.7% 0.9% Poor VBDD -7%25%1.7%5.2%6.7% Zero kWh-100%5%NA 10.1% 14.1%17.5%28.1%

Hiccup with MH application Non-electric fuels account for 23.7% - 5.7% = 18% gap between good- VBDD and poor-VBDD sites. That’s more than the 14% figure we got from annualized energy. Propose (next presentation) to accept 18% figure and make no additional VBDD adjustment. (So non-electric fuels account for differences between good-VBDD and bad-VBDD sites, and they differ by 18%). Good-VBDD homesPoor-VBDD homes All Zones Adjustment for affected homes Percent of homes affected Net adjustment Percent of homes affected Net adjustment Off-grid high -56% 4% 2% 34% 19% Off-grid med, Z1 -35% 9% 3% 14% 5% Gas heat high -69% 1% 0% Poor-VBDD 5.7% 23.7%

Recommendation By default, the RTF assumes the fraction of total energy that goes to heating is the same in poor- VBDD homes and good-VBDD homes. For single-family homes this assumption, together with the results of the annualized energy analysis, implies that poor-VBDD sites use 14% less heating energy than good-VBDD homes. This figure is not binding in all cases. Alternatives may be considered for manufactured homes where the 14% figure conflicts with other data.

Decision SF Zone 1 Summary Non-electric Heating Adjustment (15.6%) Non-energy adjustment (1.6%) Electric Heating Adjustment (82.8%) Variable Off-grid highOff-grid medGas heat highPoor-VBDDNA Adjustment4.3%6.2%5.2%1.6%82.8% SF Zone 2/3 Summary Non-electric Heating Adjustment (12.4%) Non-energy adjustment (1.7%) Electric Heating Adjustment (85.9%) Variable Off-grid highOff-grid medGas heat highPoor-VBDDNA Adjustment10.7%0.0%1.7% 85.9% I, ________, move that the RTF adopt the subcommittee recommendation as stated on the previous slide. The RTF also adopts the single-family phase II updates summarized below. Final values for the MH calibration are not addressed by this motion (those will require a separate decision).