SEEM Calibration: Phase-2 Adjustments for Failed VBDD Fits

Regional Technical Forum

August 12, 2014

2

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?

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– Presentation

• August 1, 2014– What should we do when VBDD fails: Two options– Minutes– 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.

• 2800 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 homes Poor-VBDD homes

All ZonesAdjustment 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% 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% 0% 100% 7%Final group adjustment: 13.4% 27.4%

7.0%

SF Calibration, Phase II (step 2)

Zone 1Adjustment 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% 4.3% 4.2%Off-grid med (Z1) -20% 30% 6.2% 6.2% 5.2%Gas heat high -69% 8% 5.2% 5.2% 4.3%Poor VBDD -7% 22% 1.6% 4.7% 6.3%Zero kWh -100% 5% NA NA 5.3%

Total 17.2% 20.3% 25.2%

Zones 2-3Adjustment 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% 10.7% 10.4%Gas heat high -69% 2% 1.7% 1.7% 0.9%Poor VBDD -7% 25% 1.7% 5.2% 6.7%Zero kWh -100% 5% NA 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 homes Poor-VBDD homes

All ZonesAdjustment 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% 0% 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 HeatingAdjustment

(15.6%)

Non-energy adjustment

(1.6%)

Electric Heating Adjustment

(82.8%)

Variable Off-grid high Off-grid med Gas heat high Poor-VBDD NA

Adjustment 4.3% 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 high Off-grid med Gas heat high Poor-VBDD NA

Adjustment 10.7% 0.0% 1.7% 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).