Evaluation Results of the 2004 & 2005 California Statewide ENERGY STAR® New Homes Program Clark Bernier Presented at the October 17, 2007 CALMAC Meeting
CALMAC October Total Buildings Built Under Program Single Family Multi Family
CALMAC October Inspection Findings Water Heating Efficiency Site Inspections
CALMAC October Inspection Findings AC Efficiency Site Inspections
CALMAC October Inspection Findings Window Area Site Inspections
CALMAC October Inspection Findings Other Measures Site Inspections
CALMAC October Meter-to-Model Results: SF Cooling Coastal Sites Desert Sites Meter-to- Model Analysis
CALMAC October Meter-to-Model Results SF Heating SF Water Heating Meter-to- Model Analysis
CALMAC October Meter-to-Model Results: SF Ratio Results Cooling: Coastal is 175% of model, inland is 66% - 80% of model Cooling: Coastal is 175% of model, inland is 66% - 80% of model Heating: actual is 59% - 61% of model Heating: actual is 59% - 61% of model Water Heating: actual is 81% of model Water Heating: actual is 81% of model Savings Impact: 18% lower kWh, 20% lower therms Savings Impact: 18% lower kWh, 20% lower therms Meter-to- Model Analysis
CALMAC October Meter-to-Model Conclusions Compliance models overstate usage (and thus savings) Compliance models overstate usage (and thus savings) Why? Single Family Why? Single Family It’s the people. Thermostat set point too high? Understate the average floor area per person? Meter-to- Model Analysis
CALMAC October Single Family Net-to- Gross Results Electricity NtG tends to be >1 inland Electricity NtG tends to be >1 inland Gas NtG results are <1 everywhere Gas NtG results are <1 everywhere Due to builder trade-offs in the baseline (greater inland) Due to builder trade-offs in the baseline (greater inland) More efficient water-heaters More efficient water-heaters Less efficient AC performance Less efficient AC performance Net-to- Gross
CALMAC October Single Family Savings per Unit: Comparison Across Analysis Steps Net-to- Gross
CALMAC October Single Family Final Results Ex Ante numbers based on per-unit estimates and # units built Ex Ante numbers based on per-unit estimates and # units built High kWh Inland NtG results in high realization rates High kWh Inland NtG results in high realization rates Low therms NtG results in low realization rates Low therms NtG results in low realization rates Total Savings: Total Savings: 21.5 Million inland kWh, 2.3 Million coastal kWh 21.5 Million inland kWh, 2.3 Million coastal kWh 975,000 inland therms, 44,110 coastal therms 975,000 inland therms, 44,110 coastal therms Final
CALMAC October SF Billing Analysis Results Therms, Climate Zone 12 Billing Analysis Per-unit Therms Savings, by Analysis
CALMAC October SF Billing Analysis Results kWh, Climate Zone 12 Billing Analysis Per-unit kWh Savings, by Analysis
CALMAC October Inspection Findings Multi Family Site Inspections
CALMAC October Meter-to-Model Results: MF Cooling Meter-to- Model Analysis
CALMAC October Meter-to-Model Results: MF Heating MF Water Heating Meter-to- Model Analysis
CALMAC October Meter-to-Model Results: MF Ratio Results Cooling: actual is 12% - 40% of model Cooling: actual is 12% - 40% of model Heating: actual is 16% - 21% of model Heating: actual is 16% - 21% of model Water Heating: actual is 30% of model Water Heating: actual is 30% of model Savings Impact: 69% lower kWh, 73% lower therms Savings Impact: 69% lower kWh, 73% lower therms Meter-to- Model Analysis
CALMAC October Meter-to-Model Conclusions…MF Compliance models overstate usage (and thus savings) Compliance models overstate usage (and thus savings) Why? Multifamily Why? Multifamily Multifamily models fail to account for key differences between SF and MF Occupancy patterns Economic differences Zonal comfort instead of whole-area Ignores interaction between spaces In general: Multifamily structures are more complex than Single Family, but treated the same Meter-to- Model Analysis
CALMAC October Multi Family Family Net- to-Gross Results SERA conducted interviews with builders SERA conducted interviews with builders Self-reported NtG ratio Self-reported NtG ratio Final ratio used: 0.50 Final ratio used: 0.50 Net-to- Gross
CALMAC October Multi Family Savings per Unit: Comparison Across Analysis Steps Net-to- Gross
CALMAC October Multi Family Final Results Realization rates are very low Realization rates are very low Lower-than-expected NtG of 0.5 Lower-than-expected NtG of 0.5 Large overstatement of usage/savings by tracking models Large overstatement of usage/savings by tracking models Final
CALMAC October Total Program Results Includes high-rise (not shown in this presentation) Includes high-rise (not shown in this presentation) 23.7 Million kWh, 1.26 Million Therms, 25.5 MW savings 23.7 Million kWh, 1.26 Million Therms, 25.5 MW savings Realization rates are highly variable between untilities Realization rates are highly variable between untilities Different ex ante methods (2.5x - 4.5x PG&E per-unit kWh estimates from the other IOUs) Different ex ante methods (2.5x - 4.5x PG&E per-unit kWh estimates from the other IOUs) Different mixes of coastal/inland Different mixes of coastal/inland Final
CALMAC October Program Conclusion and Recommendations - I What do builders do to achieve savings vis-à-vis non- participants What do builders do to achieve savings vis-à-vis non- participants 90% homes have tight ducts/infiltration 90% homes have tight ducts/infiltration Not tested for in the baseline Not tested for in the baseline Not generally claimed in non-participant homes (even though they might qualify for the measure) Not generally claimed in non-participant homes (even though they might qualify for the measure) Billing results from CZ 12 offer some corroboration that net savings might be even lower Billing results from CZ 12 offer some corroboration that net savings might be even lower Reduction in window area Reduction in window area (slightly) Higher equipment efficiencies (slightly) Higher equipment efficiencies Radiant barrier Radiant barrier Overhangs Overhangs Re-circulation timers on hot water systems Re-circulation timers on hot water systems
CALMAC October Program Conclusion and Recommendations - II Coastal impacts might not be worth the cost Coastal impacts might not be worth the cost Realization rates are somewhat misleading as IOUs used different methods to compute ex ante savings Realization rates are somewhat misleading as IOUs used different methods to compute ex ante savings Builders don’t always do what’s modeled Builders don’t always do what’s modeled Occupants don’t behave as modeled Occupants don’t behave as modeled Orientation has a large (17% - 25%) impact on usage/savings Orientation has a large (17% - 25%) impact on usage/savings Significant savings to be had by using the “best” orientation Significant savings to be had by using the “best” orientation Significant need to make sure the registries record the actual orientation instead of just the worst Significant need to make sure the registries record the actual orientation instead of just the worst
CALMAC October Program Conclusion and Recommendations - III Compliance models alone are a poor indicator of usage/savings Compliance models alone are a poor indicator of usage/savings Compliance-focused rather than modeling-focused Compliance-focused rather than modeling-focused Methods (including ex ante) must take this into account Methods (including ex ante) must take this into account Baseline studies need to be paired with evaluation studies so that they are complimentary Baseline studies need to be paired with evaluation studies so that they are complimentary This means better-funded baseline studies are necessary to properly quantify program savings This means better-funded baseline studies are necessary to properly quantify program savings
CALMAC October Program Conclusion and Recommendations - IV Improved tracking database(s) Improved tracking database(s) Consistent data format Consistent data format Restricted entries on fields (many 2x, 3x builder name spelling variations, etc.) Restricted entries on fields (many 2x, 3x builder name spelling variations, etc.) Record the details of failures – can find lost savings opportunities Record the details of failures – can find lost savings opportunities
CALMAC October Contact Information Clark Bernier RLW Analytics 1055 Broadway, Suite G Sonoma, CA Phone: (707) x19 Web: