evaluation results of the 2004 & 2005 california statewide energy star® new homes program clark...
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Evaluation Results of the 2004 & Evaluation Results of the 2004 & 2005 2005
California Statewide California Statewide ENERGY STAR® New Homes ENERGY STAR® New Homes
ProgramProgram
Clark BernierClark Bernier
Presented at the October 17, 2007 Presented at the October 17, 2007 CALMAC MeetingCALMAC Meeting
CALMAC October 2007 2
Total Buildings Built Under Total Buildings Built Under ProgramProgram
Utility Inland Coastal TotalPGE 11,117 1,192 12309SCE 13,145 152 13297SoCalGas 1,191 0 1191SDGE 1,256 3,060 4316TOTAL 26,709 4,404 31113
Utility Coastal Inland TotalPGE 171 204 375SCE 62 96 158SCG 80 548 628
SDGE 1,349 315 1,664Total 1,662 1,163 2,825
Single Family
Multi Family
CALMAC October 2007 3
Inspection Findings Inspection Findings Water Heating EfficiencyWater Heating Efficiency
Hot Water Energy Factor: Planned vs. Inspected
0.55
0.56
0.57
0.58
0.59
0.60
0.61
0.62
0.63
0.64
Home ID
En
erg
y F
acto
r
PlannedInspected
Site Inspection
s
CALMAC October 2007 4
Inspection Findings Inspection Findings AC EfficiencyAC Efficiency
Cooling SEER: Planned vs. Inspected
8
9
10
11
12
13
14
15
Home ID
SE
ER
PlannedInspected
Site Inspection
s
CALMAC October 2007 5
Inspection Findings Inspection Findings Window AreaWindow Area
Total Window Area: Planned vs. Inspected
0
100
200
300
400
500
600
700
800
900
1000
Home ID
Win
do
w A
rea
(Sq
ua
re F
eet)
PlannedInspected
Average Planned Window Area: 420Average Installed Window Area: 395
Site Inspection
s
CALMAC October 2007 6
Inspection FindingsInspection FindingsOther MeasuresOther Measures
Measure Planned Inspected Frequency Net Energy EffectNo Yes 0Yes No 0No Yes 4Yes No 0
92
TXV Valve
Radiant Barrier
Attic R-value
No Difference
More Efficient
More EfficientHigher than planLower than plan
Site Inspection
s
CALMAC October 2007 7
Meter-to-Model Meter-to-Model Results:Results:
SF CoolingSF Cooling
1
10
100
1000
10000
1 10 100 1000 10000
Real-Weather Modeled Site Annual Cooling kWh (log scale)
Me
tere
d S
ite
An
nu
al
Co
oli
ng
kW
h (
log
sc
ale
)
Coastal SitesDesert
Sites
Meter-to-Model
Analysis
CALMAC October 2007 8
Meter-to-Model Meter-to-Model ResultsResults
0
10000
20000
30000
40000
50000
60000
70000
0 10000 20000 30000 40000 50000 60000 70000
Real-Weather Modeled Site Annual Heating kBtu
Met
ered
Sit
e A
nn
ual
Hea
tin
g k
Btu
0
10000
20000
30000
40000
50000
60000
70000
17000 19000 21000 23000 25000 27000 29000 31000 33000
Real-Weather Modeled Site Annual Water Heating kBtu
Me
tere
d S
ite
An
nu
al
Wa
ter
He
ati
ng
kB
tu
SF HeatingSF Heating SF Water SF Water HeatingHeating
Meter-to-Model
Analysis
CALMAC October 2007 9
Meter-to-Model Meter-to-Model Results:Results:
SF Ratio ResultsSF Ratio Results
Coastal 14 1.752 49.0%Inland 72 0.797 14.3% *Desert 5 0.664 18.3% *
Coastal 14 0.589 28.9% *Inland 76 0.614 11.6% *Desert 6 0.837 25.3%
Hot Water N/A 87 0.813 10.3% *
* Indicates statistically significantly different from ratio = 1
Climate Sample nRatio Meter
Usage to Modeled Usage
Relative Precision
AC
Heat
End Use
Cooling: Coastal is 175% of model, inland is 66% - 80% of Cooling: Coastal is 175% of model, inland is 66% - 80% of modelmodel
Heating: actual is 59% - 61% of modelHeating: actual is 59% - 61% of model Water Heating: actual is 81% of modelWater Heating: actual is 81% of model
Savings Impact: 18% lower kWh, 20% lower Savings Impact: 18% lower kWh, 20% lower thermstherms
Meter-to-Model
Analysis
CALMAC October 2007 10
Meter-to-Model Meter-to-Model ConclusionsConclusions
Compliance models overstate usage Compliance models overstate usage (and thus savings)(and thus savings)
Why? Single FamilyWhy? Single Family It’s the people. Thermostat set point too high? Understate the average floor area per
person?
Meter-to-Model
Analysis
CALMAC October 2007 11
Single Family Net-to-Single Family Net-to-Gross ResultsGross Results
PGE 3,974,754 6,622,261 1.67 PGE 669,313 551,485 0.82 SCE 10,117,361 12,412,735 1.23 SCE 220,998 70,427 0.32
SoCalGas 2,078,956 1,760,013 0.85 SoCalGas NA NA NA SDGE 674,708 727,800 1.08 SDGE 831,500 668,434 0.80
TOTAL 16,845,778 21,522,809 1.28 TOTAL 1,721,811 1,290,346 0.75
Electricity (kWh)
UtilityInland
UtilityCoastal
Ex Post Gross Savings
Ex Post Net Savings
Net-to-Gross Ratio
Ex Post Gross Savings
Ex Post Net Savings
Net-to-Gross Ratio
Electricity NtG tends to be >1 inlandElectricity NtG tends to be >1 inland Gas NtG results are <1 everywhereGas 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-heatersMore efficient water-heaters Less efficient AC performanceLess efficient AC performance
PGE 1,053,484 588,538 0.56 PGE 114,116 1,077 0.01 SCE 1,006,054 336,590 0.33 SCE 3,912 -74 (0.02)
SoCalGas 55,012 22,154 0.40 SoCalGas NA NA NA SDGE 95,741 28,194 0.29 SDGE 205,031 43,107 0.21
TOTAL 2,210,291 975,476 0.44 TOTAL 323,059 44,110 0.14
Gas (therms)
UtilityInland
UtilityCoastal
Ex Post Gross Savings
Ex Post Net Savings
Net-to-Gross Ratio
Ex Post Gross Savings
Ex Post Net Savings
Net-to-Gross Ratio
Net-to-Gross
CALMAC October 2007 12
Single Family Savings per Single Family Savings per Unit: Comparison Across Unit: Comparison Across
Analysis StepsAnalysis Steps
Single Family kWh Savings per Unit
0100200300400500600700800
Gross Meter-AdjustedGross
Net
kW
h/u
nit s
avin
gs
Single Family Gas Therms Savings per Unit
020406080
100120140160
Gross Meter-AdjustedGross
Net
The
rms/
unit
sav
ings
Net-to-Gross
CALMAC October 2007 13
Single Family Final Single Family Final ResultsResults
Ex Ante numbers based on per-unit estimates and # Ex Ante numbers based on per-unit estimates and # units builtunits built
High kWh Inland NtG results in high realization ratesHigh kWh Inland NtG results in high realization rates Low therms NtG results in low realization ratesLow therms NtG results in low realization rates Total Savings:Total Savings:
21.5 Million inland kWh, 2.3 Million coastal kWh21.5 Million inland kWh, 2.3 Million coastal kWh 975,000 inland therms, 44,110 coastal therms975,000 inland therms, 44,110 coastal therms
Final
PGE 2,929,935 6,622,261 596 2.26 PGE 327,638 551,485 463 1.68 SCE 13,218,550 12,412,735 944 0.94 SCE NA 70,427 463 NA
SoCalGas 841,921 1,760,013 1,478 2.09 SoCalGas 0 NA NA NA SDGE 812,883 727,800 579 0.90 SDGE 1,980,432 668,434 218 0.34
TOTAL 17,803,289 21,522,809 806 1.21 TOTAL 2,308,070 1,290,346 293 0.56
Electricity (kWh)Inland Coastal
Net Unit Savings
UtilityUtility Net Ex Ante
Net Ex Post Savings
Realization Rate
Net Ex Ante
Net Ex Post Savings
Realization Rate
Net Unit Savings
PGE 1,153,676 588,538 53 0.51 PGE 127,330 1,077 0.9 0.01 SCE NA 336,590 26 NA SCE NA -74 -0.5 NA
SoCalGas 29,394 22,154 19 0.75 SoCalGas 0 NA NA NA SDGE 19,694 28,194 22 1.43 SDGE -13,709 43,107 14 -3.1
TOTAL 1,202,764 975,476 37 0.81 TOTAL 113,621 44,110 10 0.39
Net Unit Savings
Gas (therms)Inland Coastal
Utility Net Ex Ante
Net Ex Post Savings
Realization Rate
Utility Net Ex Ante
Net Ex Post Savings
Realization Rate
Net Unit Savings
CALMAC October 2007 14
SF Billing Analysis SF Billing Analysis Results Results
Therms, Climate Zone 12Therms, Climate Zone 12
0
20
40
60
80
100
120
140
160
Orientation-AdjustedGross
Ex Post Gross Ex Post Net Billing
ther
ms
Billing Analysis
Per-unit Therms Savings, Per-unit Therms Savings, by Analysisby Analysis
CALMAC October 2007 15
SF Billing Analysis SF Billing Analysis Results Results
kWh, Climate Zone 12kWh, Climate Zone 12
-300
-200
-100
0
100
200
300
400
500
600
700
Orientation-Adjusted
Gross
Ex Post Gross Ex Post Net Billing
kW
h
Billing Analysis
Per-unit kWh Per-unit kWh Savings, by AnalysisSavings, by Analysis
CALMAC October 2007 16
Inspection FindingsInspection FindingsMulti FamilyMulti Family
Site Inspection
s
ID
Heating Efficiency Tracking
Heating Efficiency Verified
Heating Efficiency
Type
Heating System Type
Cooling Efficiency Tracking
Cooling Efficiency Verified
DHW EF - Tracking
DHW EF - Verified
7.0 7 HSPF HPSplit 12 12 RE 0.82 N/O0.80 0.81 AFUE Hydronic 10 12 DHW 0.61 Boiler 0.857.8 7.8 HSPF HPSplit 10 10 0.00 Inst 0.81
0.75 0.78 AFUE Hydronic 10 10 0.62 0.600.75 0.75 AFUE Hydronic 10 10 0.61 0.610.75 0.78 AFUE Hydronic 10 10 0.60 0.600.76 0.75 AFUE Hydronic 10 10 0.62 0.620.75 0.75 AFUE Hydronic 10 10 0.54 0.54
No EF 0.70 AFUE Hydronic 10 10 0.58 0.600.75 0.75 AFUE Hydronic 10 10 0.60 0.620.78 0.75 AFUE Hydronic 10 10 0.62 0.620.79 0.75 AFUE Hydronic 10 10 0.61 0.626.8 N/O HSPF Room HP 10.66 N/O DHW 0.62 Boiler 0.82
0.78 0.75 AFUE Hydronic No cooling No cooling 0.56 0.590.80 0.76 AFUE Hydronic No cooling No cooling 0.59 0.580.82 0.74 AFUE Hydronic 12 12 0.63 0.62
No EF N/O AFUE Hydronic 11 N/O 0.62 0.557.8 N/O HSPF HPSplit 12.5 12 0.53 0.58
No EF N/O AFUE Hydronic 12 12 0.61 0.62No EF 0.80 HSPF HPSplit 10 10 0.64 0.62
0.80 0.80 AFUE FAU No cooling No cooling 0.62 0.620.80 N/O AFUE FAU No EF 10 0.60 N/O0.80 N/O AFUE FAU 10 11 0.60 N/O
EF - Energy factor DHW - Standard domestic hot water heaterNo EF - No efficiency recorded in tracking Boiler - Central boilerRE - Recovery efficiency Inst - Instantaneous hot water heaterN/O - Not observable
Hom
e I
D's
Suppre
ssed
CALMAC October 2007 17
Meter-to-Model Meter-to-Model Results:Results:
MF CoolingMF Cooling
1000
10000
100000
1000000
10000000
10000
100000
1000000
10000000
Real-Weather Modeled Site Annual Cooling Source Kbtu (log scale)
Met
ered
Sit
e A
nn
ua
l C
oo
lin
g S
ou
rce
KB
tu (
log
sca
le)
Meter-to-Model
Analysis
CALMAC October 2007 18
Meter-to-Model Meter-to-Model Results:Results:
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
Real-Weather Modeled Site Annual Heating Source KBtu
Met
ered
Sit
e A
nn
ual
Hea
tin
g S
ou
rce
KB
tu
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
0 2000000
4000000
6000000
8000000
10000000
12000000
Real-Weather Modeled Site Annual Water Heating Source KBtu
Met
ered
Sit
e A
nn
ual
Wat
er H
eati
ng
So
urc
e K
Btu
MF HeatingMF Heating MF Water MF Water HeatingHeating
Meter-to-Model
Analysis
CALMAC October 2007 19
Meter-to-Model Meter-to-Model Results:Results:
MF Ratio ResultsMF Ratio Results
Coastal 6 0.118 77.5% *Inland 15 0.397 45.8% *Coastal 10 0.161 36.0% *Inland 12 0.212 68.8% *
Hot Water NA 22 0.301 25.2% * * Indicates statistically significantly different from ratio = 1
Sample n
AC
Heat
Ratio Meter Usage to
Modeled Usage
Relative Precision
ClimateEnd Use
Cooling: actual is 12% - 40% of modelCooling: actual is 12% - 40% of model Heating: actual is 16% - 21% of modelHeating: actual is 16% - 21% of model Water Heating: actual is 30% of modelWater Heating: actual is 30% of model
Savings Impact: 69% lower kWh, 73% lower Savings Impact: 69% lower kWh, 73% lower thermstherms
Meter-to-Model
Analysis
CALMAC October 2007 20
Meter-to-Model Meter-to-Model Conclusions…MFConclusions…MF
Compliance models overstate usage (and Compliance models overstate usage (and thus savings)thus savings)
Why? MultifamilyWhy? 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 2007 21
Multi Family Family Multi Family Family Net-to-Gross ResultsNet-to-Gross Results
SERA conducted interviews with SERA conducted interviews with buildersbuilders
Self-reported NtG ratioSelf-reported NtG ratio Final ratio used: Final ratio used: 0.500.50
Net-to-Gross
CALMAC October 2007 22
Multi Family Savings per Multi Family Savings per Unit: Comparison Across Unit: Comparison Across
Analysis StepsAnalysis Steps
Net-to-Gross
Multi Family kWh Savings
0
100
200
300
400
500
600
700
800
Gross Meter-AdjustedGross
Net
kW
h/y
ear
/uni
t
Multi Family kWh Savings
0
20
40
60
80
100
120
140
160
Gross Meter-AdjustedGross
Net
kW
h/ye
ar/u
nit
Single Family kWh Savings per Unit
0100200300400500600700800
Gross Meter-AdjustedGross
Net
kW
h/u
nit s
avin
gs
Single Family Gas Therms Savings per Unit
020406080
100120140160
Gross Meter-AdjustedGross
Net
The
rms/
unit
sav
ings
CALMAC October 2007 23
Multi Family Final Multi Family Final ResultsResults
Realization rates are very lowRealization rates are very low Lower-than-expected NtG of 0.5Lower-than-expected NtG of 0.5 Large overstatement of usage/savings by tracking Large overstatement of usage/savings by tracking
modelsmodels
Final
PGE 309,584 79,929 0.26 PGE 171,991 6,673 0.04 SCE 494,614 111,230 0.22 SCE 199,786 8,195 0.04
SoCalGas 1,752,205 310,535 0.18 SoCalGas 103,934 3,776 0.04 SDGE 472,402 65,258 0.14 SDGE 1,658,253 47,500 0.03
TOTAL 3,028,806 566,952 0.19 TOTAL 2,133,965 66,144 0.03
PGE 103,540 15,538 0.15 PGE 57,522 10,061 0.17 SCE 0 16,971 NA SCE 0 5,665 NA
SoCalGas 176,653 44,445 0.25 SoCalGas 10,478 2,548 0.24 SDGE 47,626 15,289 0.32 SDGE 167,181 45,281 0.27
TOTAL 327,820 92,243 0.28 TOTAL 235,182 63,556 0.27
CoastalNet Ex Ante
Net Ex PostRealization
RateNet Ex Ante
Net Ex PostRealization
RateUtility
InlandUtility
Realization Rate
Gas (therms)
Utility UtilityNet Ex Ante
Net Ex PostRealization
Rate
CoastalInlandElectricity (kWh)
Net Ex Ante
Net Ex Post
CALMAC October 2007 24
Total Program ResultsTotal 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 untilitiesRealization rates are highly variable between untilities
Different ex ante methods (2.5x - 4.5x PG&E per-Different ex ante methods (2.5x - 4.5x PG&E per-unit kWh estimates from the other IOUs) unit kWh estimates from the other IOUs)
Different mixes of coastal/inlandDifferent mixes of coastal/inland
Final
Net ExAnte
Net ExPost
RealizationRate
Net Ex Ante
Net Ex Post
RealizationRate
Net Ex Ante
Net Ex Post
RealizationRate
PGE 3,786,119 7,241,155 1.91 1,457,778 634,533 0.44 4,170 7,686 1.84 SCE 14,038,346 12,694,362 0.90 NA 371,772 NA 17,980 13,730 0.76
SoCalGas 2,874,807 2,050,545 0.71 234,344 97,608 0.42 4,194 2,202 0.53 SDGE 5,139,179 1,755,755 0.34 242,489 151,521 0.62 8,141 1,886 0.23 Total 25,838,451 23,741,818 0.92 1,934,611 1,255,434 0.65 34,485 25,504 0.74
kWh Therms kWUtility
CALMAC October 2007 25
Program Conclusion and Program Conclusion and Recommendations - IRecommendations - I
What do builders do to achieve savings vis-à-vis non-What do builders do to achieve savings vis-à-vis non-participantsparticipants 90% homes have tight ducts/infiltration90% homes have tight ducts/infiltration
Not tested for in the baselineNot tested for in the baseline Not generally claimed in non-participant homes Not generally claimed in non-participant homes
(even though they might qualify for the measure)(even though they might qualify for the measure) Billing results from CZ 12 offer some Billing results from CZ 12 offer some
corroboration that net savings might be even corroboration that net savings might be even lowerlower
Reduction in window areaReduction in window area (slightly) Higher equipment efficiencies(slightly) Higher equipment efficiencies Radiant barrierRadiant barrier OverhangsOverhangs Re-circulation timers on hot water systemsRe-circulation timers on hot water systems
CALMAC October 2007 26
Program Conclusion and Program Conclusion and Recommendations - IIRecommendations - II
Coastal impacts might not be worth the costCoastal impacts might not be worth the cost Realization rates are somewhat misleading as Realization rates are somewhat misleading as
IOUs used different methods to compute ex ante IOUs used different methods to compute ex ante savings savings
Builders don’t always do what’s modeledBuilders don’t always do what’s modeled Occupants don’t behave as modeledOccupants don’t behave as modeled Orientation has a large (17% - 25%) impact on Orientation has a large (17% - 25%) impact on
usage/savingsusage/savings Significant savings to be had by using the Significant savings to be had by using the
“best” orientation“best” orientation Significant need to make sure the registries Significant need to make sure the registries
record the actual orientation instead of just record the actual orientation instead of just the worstthe worst
CALMAC October 2007 27
Program Conclusion and Program Conclusion and Recommendations - IIIRecommendations - III
Compliance models alone are a poor indicator Compliance models alone are a poor indicator of usage/savingsof usage/savings Compliance-focused rather than modeling-Compliance-focused rather than modeling-
focusedfocused Methods (including ex ante) must take this Methods (including ex ante) must take this
into accountinto account Baseline studies need to be paired with Baseline studies need to be paired with
evaluation studies so that they are evaluation studies so that they are complimentarycomplimentary This means better-funded baseline studies This means better-funded baseline studies
are necessary to properly quantify program are necessary to properly quantify program savingssavings
CALMAC October 2007 28
Program Conclusion and Program Conclusion and Recommendations - IVRecommendations - IV
Improved tracking database(s)Improved tracking database(s) Consistent data formatConsistent data format Restricted entries on fields (many 2x, 3x Restricted entries on fields (many 2x, 3x
builder name spelling variations, etc.)builder name spelling variations, etc.) Record the details of failures – can find lost Record the details of failures – can find lost
savings opportunitiessavings opportunities
CALMAC October 2007 29
Contact InformationContact Information
Clark BernierClark BernierRLW AnalyticsRLW Analytics1055 Broadway, Suite G1055 Broadway, Suite GSonoma, CA 94576Sonoma, CA 94576
Phone: (707) 939-8823 x19Phone: (707) 939-8823 x19Email:Email:
[email protected]@rlw.comWeb:Web: http://www.rlw.comhttp://www.rlw.com