a comparison of measure avoided cost calculations using utility tou load shapes and deer hourly...
TRANSCRIPT
A Comparison of Measure Avoided Cost Calculations
using Utility TOU Load Shapes and DEER Hourly Measure Savings
14 March 2006
Measure Avoided Cost Calculations
For this analysis, we compared annual avoided costs for selected measures determined using IOU load shapes and using DEER hourly savings results.
This work does NOT examine or compare the magnitude of measure savings in the IOU filings vs. DEER savings for the same measure; this work only shows the relative avoided cost values when the SAME measure annual savings has an avoided cost calculated using the DEER hourly profile, or the IOU hourly or TOU profiles.
The components used for the analysis include:– cpucAvoided26.xls from E3
• levelized hourly avoided cost values were extracted from this spreadsheet for each utility/climate zone combination examined and for a range of measure expected life values.
• contains hourly TOU period definitions for each utility
– Utility specific “shape viewer” spreadsheets• “SCE-res2.xls”: SCE residential spreadsheet provides TOU values by end-
use and climate zone for new construction, and by end-use for retrofit.• “SCE-nonres2.xls”: SCE non-residential spreadsheet provided TOU values
by building type, end-use/measure-type and climate zone for new construction, and by building type and end-use for retrofit.
• “SDG&E3.xls”: SDG&E spreadsheet provides TOU values by building type and end-use for both residential and commercial building types.
• “ComViewer.xls” and “ResViewer.xls”: PG&E spreadsheets that provided TOU load shapes by end-use for building sector. These spreadsheets also contain the hourly load profiles by building type and end-use.
– Attachment II-T3 tables• For each of the utilities, these tables map the TOU load shapes used for
each of the measures.
Measure Avoided Cost Calculations
Measure Avoided Cost Calculations
The DEER version of eQUEST was used for this analysis, with minor modifications.– hourly whole-building electricity use for both the base
case run and the measure run is now written to a file. End-use hourly values are not yet available.
– some improvements were made to the DEER process to fix known problems:
• minor changes to schedules (open-closed hours)
• night-cycle control added for hot climates
• residential HVAC performance curves updated
Measure Avoided Cost Calculations
Measures by Building TypeLarge Office Small Retail Grocery Single Family
Chiller efficiency Pkg AC efficiency Pkg AC efficiency AC efficiency
Indoor Lighting reduction Indoor Lighting reductionIndoor Lighting
reduction Refg Charge
Economizer Maintenance Reduce Over-Ventilation Reduce Over-Ventilation Duct Sealing
Side Daylighting Top Daylighting Top Daylighting Low-E Window
LowSC Window on West LowSC Window on WestLowSC Window on
West Indoor Lighting
LowSC Window on East LowSC Window on East LowSC Window on East Ceiling Insulation
Supply Fan Motor Eff.LowSC Window on
South Zero Heat Doors
CHW Loop Motor Eff. Night Covers
2-Speed Cooling Tower
Climate Zones by UtilityPG&E SCE SDG&E
CZ03 CZ09 CZ07
CZ13 CZ15 CZ15
Preliminary conclusions Use of TOU load shapes typically under-predicts the avoided cost of Commercial measures relative to hourly load shapes by up to 20% (or more)– For the commercial building cases examined, the average difference
between TOU avoided cost to Hourly Avoided cost is 12%
DEER TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Large Office
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
Retro NC Retro NC Retro NC Retro NC Retro NC
CZ03 CZ03 CZ07 CZ07 CZ09 CZ09 CZ13 CZ13 CZ15 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Indoor Ltg reduction
Side Daylighting
LowSC Window on West
LowSC Window on East
Econo Maint. (retro only)
Chiller eff.
Supply Fan Motor Eff.
CHW Loop Motor Eff.
Preliminary conclusions Use of TOU load shapes typically under-predicts the avoided cost of Commercial measures relative to hourly load shapes by up to 20% (or more)– For the commercial building cases examined, the average difference
between TOU avoided cost to Hourly Avoided cost is 12%
DEER TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Small Retail
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
Retro NC Retro NC Retro NC Retro NC Retro NC
CZ03 CZ03 CZ07 CZ07 CZ09 CZ09 CZ13 CZ13 CZ15 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Ltg reduced
Pkg AC eff.
Reduce OverVent
Top Daylighting
LowSC Window on West
LowSC Window on East
LowSC Window on South
Preliminary conclusions Use of TOU load shapes typically under-predicts the avoided cost of Commercial measures relative to hourly load shapes by up to 20% (or more)– For the commercial building cases examined, the average difference
between TOU avoided cost to Hourly Avoided cost is 12%
DEER TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Grocery
(0.2)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Retro NC Retro NC Retro NC Retro NC Retro NC
CZ03 CZ03 CZ07 CZ07 CZ09 CZ09 CZ13 CZ13 CZ15 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Ltg reduced
Pkg AC eff.
Reduce OverVent
Top Daylighting
LowSC Window on West
LowSC Window on East
Zero Heat Doors
Night Covers
Preliminary conclusions Use of TOU load shapes typically under-predicts the avoided cost of Residential measures relative to hourly load shapes by up to 30%– For the residential cases examined, the average difference between TOU
avoided cost to Hourly Avoided cost is 19%
DEER TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Single-Family Residential
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
Retro NC Retro NC Retro NC Retro NC Retro NC
CZ03 CZ03 CZ07 CZ07 CZ09 CZ09 CZ13 CZ13 CZ15 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Indoor Lighting
AC efficiency
Refg Charge
Duct Sealing
Low-E Window
Ceiling Insulation
Preliminary conclusions
Difference between DEER Hourly and TOU Avoided Cost
Measures Large Office Small Retail Grocery Single-Family
Lighting 2.7% 6.3% 2.9% 3.5%
HVAC 6.8% 17.5% 21.1% 20.2%
All Measures 6.5% 14.5% 37.3% 20.5%
The agreement between annual avoided costs calculated with hourly and with TOU load shapes varies by building type and measure
Preliminary conclusions
Use of a Super-TOU load shape for the DEER TOU Avoided Cost calculation improved the agreement between the hourly and the TOU annual avoided costs by about 20%
– For the cases examined, the average difference between Super-TOU avoided cost to Hourly Avoided cost is 11% (compared to 13% for the standard TOU).
– For commercial buildings, the use of a super TOU period improved the comparison of Lighting vs. HVAC measures only slightly (about 10%).
– For the single-family residential building, the use of a super TOU period did bring the Lighting and HVAC ratios closer together (by about 25%).
– For this analysis, Super-TOU is defined as a new TOU period containing the 100 highest levelized avoided cost hours in the Summer On-Peak period.
Preliminary conclusions
Difference between DEER Hourly and TOU Avoided Cost
Measures Large Office Small Retail Grocery Single-Family
Lighting 2.7% 6.3% 2.9% 3.5%
HVAC 6.8% 17.5% 21.1% 20.2%
All Measures 6.5% 14.5% 37.3% 20.5%
Difference between DEER Hourly and Super TOU Avoided CostMeasures Large Office Small Retail Grocery Single-Family
Lighting 2.3% 6.1% 2.9% 3.8%
HVAC 5.7% 14.7% 17.0% 16.5%
All Measures 5.4% 12.4% 35.8% 15.4%
Preliminary conclusions Use of IOU load shapes can under-predict and over-predict the avoided cost of measures relative to DEER hourly load shapes by up to 30% (or more)– For the cases examined, the average difference between the Utility TOU
avoided cost to DEER Hourly Avoided cost is 20%.
Utility TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Large Office
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
PG&E PG&E PG&E PG&E SCE SCE SCE SCE SDG&E SDG&E SDG&E SDG&E
Retro Retro NC NC Retro Retro NC NC Retro Retro NC NC
CZ03 CZ13 CZ03 CZ13 CZ09 CZ15 CZ09 CZ15 CZ07 CZ15 CZ07 CZ15
Uti
lity
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Indoor Ltg reduction
Side Daylighting
LowSC Window on West
LowSC Window on East
Econo Maint. (retro only)
Chiller eff.
Supply Fan Motor Eff.
CHW Loop Motor Eff.
Preliminary conclusions Use of IOU load shapes can under-predict and over-predict the avoided cost of measures relative to DEER hourly load shapes by up to 30% (or more)– For the cases examined, the average difference between the Utility TOU
avoided cost to DEER Hourly Avoided cost is 20%.
Utility TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Small Retail
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
PG&E PG&E PG&E PG&E SCE SCE SCE SCE SDG&E SDG&E SDG&E SDG&E
Retro Retro NC NC Retro Retro NC NC Retro Retro NC NC
CZ03 CZ13 CZ03 CZ13 CZ09 CZ15 CZ09 CZ15 CZ07 CZ15 CZ07 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Ltg reduced
Pkg AC eff.
Reduce OverVent
Top Daylighting
LowSC Window on West
LowSC Window on East
LowSC Window on South
Preliminary conclusions Use of IOU load shapes can under-predict and over-predict the avoided cost of measures relative to DEER hourly load shapes by up to 30% (or more)– For the cases examined, the average difference between the Utility TOU
avoided cost to DEER Hourly Avoided cost is 20%.
Utility TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Grocery
(0.2)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
PG&E PG&E PG&E PG&E SCE SCE SCE SCE SDG&E SDG&E SDG&E SDG&E
Retro Retro NC NC Retro Retro NC NC Retro Retro NC NC
CZ03 CZ13 CZ03 CZ13 CZ09 CZ15 CZ09 CZ15 CZ07 CZ15 CZ07 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Ltg reduced
Pkg AC eff.
Reduce OverVent
Top Daylighting
LowSC Window on West
LowSC Window on East
Zero Heat Doors
Night Covers
Preliminary conclusions Use of IOU load shapes can under-predict and over-predict the avoided cost of measures relative to DEER hourly load shapes by up to 30% (or more)– For the cases examined, the average difference between the Utility TOU
avoided cost to DEER Hourly Avoided cost is 20%.
Utility TOU Avoided Cost / DEER Hourly Avoided Costfor Measures in Single-Family Residential
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
PG&E PG&E PG&E PG&E SCE SCE SCE SCE SDG&E SDG&E SDG&E SDG&E
Retro Retro NC NC Retro Retro NC NC Retro Retro NC NC
CZ03 CZ13 CZ03 CZ13 CZ09 CZ15 CZ09 CZ15 CZ07 CZ15 CZ07 CZ15
DE
ER
TO
U /
DE
ER
Ho
url
y av
oid
ed c
ost
Indoor Lighting
AC efficiency
Refg Charge
Duct Sealing
Low-E Window
Ceiling Insulation
Preliminary conclusions Use of the IOU load shapes under-predicts the avoided cost for HVAC measures by a wider margin than lighting measures
– For the cases examined, the average difference between the Utility TOU avoided cost and the DEER Hourly Avoided cost is 9% for the indoor lighting measure.
– All other measure categories had significantly higher differences between Utility TOU and DEER Hourly avoided costs.
Measure Category Average Difference
Indoor Lighting Reduction 9%
Cooling Efficiency Improvement 27%
Economizer / OA Reduction 53%
Daylighting 17%
Low SC Glass on West 13%
Low SC Glass on East 19%
Preliminary conclusions The agreement between annual avoided costs calculated with hourly
and with Utility TOU load shapes varies by building type and measure.
Large Office Small RetailAverage Average
Measure Difference Measure DifferenceIndoor Ltg reduction 0.11 Indoor Ltg reduction 0.10Side Daylighting 0.17 Top Daylighting 0.15LowSC Window on West 0.08 LowSC Window on West 0.16LowSC Window on East 0.19 LowSC Window on East 0.20Chiller eff. 0.21 LowSC Window on South 0.18Supply Fan Motor Eff. 0.15 Pkg AC eff. 0.24CHW Loop Motor Eff. 0.08 Reduce OverVent 0.502-Speed Tower 0.55Econo Maint. (retro only) 0.60
Grocery Single FamilyAverage Average
Measure Difference Measure DifferenceIndoor Ltg reduction 0.05 Indoor Ltg reduction 0.03Top Daylighting 0.18 Low-E Window 0.14LowSC Window on West 0.15 Ceiling Insulation 0.41LowSC Window on East 0.18 AC efficiency 0.21Pkg AC eff. 0.37 Refg Charge 0.15Reduce OverVent 0.48 Duct Sealing 0.17Zero Heat Doors 0.34Night Covers 6.87
Preliminary conclusions
Building and end use load shapes, as used by the current E3 calculators, do not well represent measure impact shapes in most cases
The use of older building and end use load shapes used for the current filings amplify this difference.
Preliminary conclusions IOU load shapes can work quite well …
DEER Measure Savings and Utility End-Use TOU Loadshapes
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Smr-On Smr-Ptl Smr-Off Wtr-On Wtr-Ptl Wtr-Off
frac
tion
of e
nerg
y sa
ving
s/us
e du
ring
TO
U p
erio
d
DEER TOU Loadshape SCE TOU LoadshapeSCE TOU from Hourly Loadshape fraction of annual hours in TOU period
SCE, Office, CZ09 - Measure: Chiller Efficiency Improvement
when the IOU load shape follows the same trends as the measure load shape.
Ratio of Annual Avoided Cost to DEER Hourly Avoided Cost
0.910.95
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
hourly TOU TOU
DEER DEER SCE
An
nu
al A
void
ed $
DE
ER
Ho
url
y A
nn
ual
Avo
ided
$
SCE, Office, CZ09 - Measure: Chiller Efficiency Improvement
Preliminary conclusions But if the TOU load shape doesn’t match the Measure load shape …
then the annual avoided cost may be significantly under or over-estimated.
DEER Measure Savings and Utility End-Use TOU Loadshapes
0.00
0.10
0.20
0.30
0.40
0.50
0.60
Smr-On Smr-Ptl Smr-Off Wtr-On Wtr-Ptl Wtr-Off
fra
cti
on
of
en
erg
y s
av
ing
s/u
se
du
rin
g T
OU
pe
rio
d
DEER TOU Loadshape SCE TOU LoadshapeSCE TOU from Hourly Loadshape fraction of annual hours in TOU period
SCE, Office, CZ09 - Measure: Perimeter Side Daylighting
Ratio of Annual Avoided Cost to DEER Hourly Avoided Cost
0.97
0.79
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
hourly TOU TOU
DEER DEER SCEA
nn
ual
Avo
ided
$D
EE
R H
ou
rly
An
nu
al A
void
ed $
SCE, Office, CZ09 - Measure: Perimeter Side Daylighting
Preliminary conclusions But if the TOU load shape doesn’t match the Measure load shape …
then the annual avoided cost may be significantly under or over-estimated.
Ratio of TOU Avoided Cost to DEER Hourly Avoided Cost
-0.10
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
Smr-On Smr-Ptl Smr-Off Wtr-On Wtr-Ptl Wtr-Off
TOU
Avo
ided
$D
EER
Hou
rly A
nnua
l Avo
ided
$
DEER Hourly DEER TOU SCE TOU SCE Hourly
SCE, Office, CZ09 - Measure: Economizer Maintenance
Ratio of Annual Avoided Cost to DEER Hourly Avoided Cost
1.05
1.21
0.30.40.50.60.70.80.91.01.11.21.3
hourly TOU TOU
DEER DEER SCE
An
nu
al A
void
ed $
DE
ER
Ho
url
y A
nn
ual
Avo
ided
$
SCE, Office, CZ09 - Measure: Economizer Maintenance
Preliminary conclusions And even a TOU load shape that is quite different from the measure load shape …
can lead to a “correct” answer due to compensating errors.
DEER Measure Savings and Utility End-Use TOU Loadshapes
0.00
0.10
0.20
0.30
0.40
0.50
0.60
Smr-On Smr-Ptl Smr-Off Wtr-On Wtr-Ptl Wtr-Off
fra
cti
on
of
en
erg
y s
av
ing
s/u
se
du
rin
g T
OU
pe
rio
d
DEER TOU Loadshape PG&E TOU Loadshape fraction of annual hours in TOU period
PG&E, Office, CZ03 - Measure: Economizer Maintenance
Ratio of Annual Avoided Cost to DEER Hourly Avoided Cost
1.071.02
0.3
0.40.5
0.60.7
0.80.9
1.01.1
1.2
hourly TOU TOU
DEER DEER PG&E
An
nu
al A
void
ed $
DE
ER
Ho
url
y A
nn
ual
Avo
ided
$
PG&E, Office, CZ03 - Measure: Economizer Maintenance
Preliminary conclusions Some measures do not lend themselves to be summarized by any TOU end-use load shape:
Measures that save energy during some TOU periods but use more energy during other TOU periods
cannot be approximated by an end-use load shape.
Ratio of TOU Avoided Cost to DEER Hourly Avoided Cost
-3.00
-2.00
-1.00
0.00
1.00
2.00
3.00
4.00
5.00
6.00
Smr-On Smr-Ptl Smr-Off Wtr-On Wtr-Ptl Wtr-Off
TO
U A
void
ed $
DE
ER
Ho
url
y A
nn
ual
Avo
ided
$
DEER Hourly DEER TOU SCE TOU SCE Hourly
SCE, Grocery, CZ15 - Measure: Night Covers for Display Cases (medium temp)
This measure saves over 5000 kWh per
year in a typical sized grocery store, but increases demand during the summer
on-peak period.
Hourly Load Shape Comparison
PG&E Enduse Load Shape
0
0.0001
0.0002
0.0003
0.0004
0.0005
0.0006
0.0007
0.0008
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Weekday Hour
frac
tio
n o
f an
nu
al t
ota
l
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Office, Cooling, CZ13, Weekdays
DEER Measure Load Shape
-0.0004
-0.0002
0
0.0002
0.0004
0.0006
0.0008
0.001
0.0012
0.0014
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Weekday Hour
frac
tio
n o
f an
nu
al t
ota
l kW
h s
avin
gs Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
PG&E, Office, CZ13 - Measure: Economizer Maintenance
The hourly impact of economizer maintenance
has little in common with the hourly cooling profile.
Hourly Load Shape Comparison
PG&E Enduse Load Shape
0
0.0001
0.0002
0.0003
0.0004
0.0005
0.0006
0.0007
0.0008
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Weekday Hour
frac
tio
n o
f an
nu
al t
ota
l
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Office, Cooling, CZ13, Weekdays
DEER Measure Load Shape
-0.0005
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Weekday Hour
frac
tio
n o
f an
nu
al t
ota
l kW
h s
avin
gs Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
PG&E, Office, CZ13 - Measure: LowSC Glass on East
The impact of low shading coefficient glass on the
East has a much different load shape than cooling in
general.
Hourly Load Shape Comparison
PG&E Enduse Load Shape
0
0.0001
0.0002
0.0003
0.0004
0.0005
0.0006
0.0007
0.0008
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Weekday Hour
frac
tio
n o
f an
nu
al t
ota
l
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Office, Cooling, CZ13, Weekdays
DEER Measure Load Shape
-0.0005
0
0.0005
0.001
0.0015
0.002
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Weekday Hour
frac
tio
n o
f an
nu
al t
ota
l kW
h s
avin
gs Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
PG&E, Office, CZ13 - Measure: LowSC Glass on West
The impact of low shading coefficient glass on the West has a much different load shape than
cooling in general.
demand definition
Demand Savings - kW
Demand PeriodChiller
EfficiencyLighting
ReductionAC
EfficiencyLighting
Reduction
Peak Hour 156.1 183.4 1.23 0.072Peak 9-Hour Window 121.9 140.9 0.97 0.049Super-TOU period 112.6 128.0 0.85 0.050Summer On-Peak Period 89.6 115.6 0.56 0.049
PG&E, CZ13Large Office Single Family
Demand Savingsfraction of peak hour
Chiller Efficiency
Lighting Reduction
AC Efficiency
Lighting Reduction
Peak Hour 1.00 1.00 1.00 1.00Peak 9-Hour Window 0.78 0.77 0.78 0.68Super-TOU period 0.72 0.70 0.69 0.69Summer On-Peak Period 0.57 0.63 0.46 0.68
Large Office Single FamilyPG&E, CZ13