Transcript A Comparison of Measure Avoided Cost Calculations

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.
Measure Avoided Cost Calculations
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 enduse 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
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 Type
Large Office
Small Retail
Grocery
Single Family
Chiller efficiency
Pkg AC efficiency
Pkg AC efficiency
AC efficiency
Indoor Lighting reduction
Indoor Lighting reduction
Indoor 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 West
LowSC 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 Utility
PG&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 Cost
for Measures in Large Office
DEER TOU / DEER Hourly avoided cost
1.4
1.3
Indoor Ltg reduction
1.2
Side Daylighting
1.1
LowSC Window on West
LowSC Window on East
1.0
Econo Maint. (retro only)
0.9
Chiller eff.
Supply Fan Motor Eff.
0.8
CHW Loop Motor Eff.
0.7
0.6
0.5
Retro
NC
Retro
NC
Retro
NC
Retro
NC
Retro
NC
CZ03
CZ03
CZ07
CZ07
CZ09
CZ09
CZ13
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 Cost
for Measures in Small Retail
DEER TOU / DEER Hourly avoided cost
1.4
1.3
1.2
Ltg reduced
Pkg AC eff.
1.1
Reduce OverVent
1.0
Top Daylighting
LowSC Window on West
0.9
LowSC Window on East
LowSC Window on South
0.8
0.7
0.6
0.5
Retro
NC
Retro
NC
Retro
NC
Retro
NC
Retro
NC
CZ03
CZ03
CZ07
CZ07
CZ09
CZ09
CZ13
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 Cost
for Measures in Grocery
DEER TOU / DEER Hourly avoided cost
1.4
1.2
Ltg reduced
1.0
Pkg AC eff.
Reduce OverVent
0.8
Top Daylighting
LowSC Window on West
0.6
LowSC Window on East
Zero Heat Doors
0.4
Night Covers
0.2
0.0
(0.2)
Retro
NC
Retro
NC
Retro
NC
Retro
NC
Retro
NC
CZ03
CZ03
CZ07
CZ07
CZ09
CZ09
CZ13
CZ13
CZ15
CZ15
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 Cost
for Measures in Single-Family Residential
DEER TOU / DEER Hourly avoided cost
1.4
1.3
1.2
Indoor Lighting
1.1
AC efficiency
Refg Charge
1.0
Duct Sealing
Low-E Window
0.9
Ceiling Insulation
0.8
0.7
0.6
0.5
Retro
NC
Retro
NC
Retro
NC
Retro
NC
Retro
NC
CZ03
CZ03
CZ07
CZ07
CZ09
CZ09
CZ13
CZ13
CZ15
CZ15
Preliminary conclusions
The agreement between annual avoided costs calculated
with hourly and with TOU load shapes varies by building
type and measure
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%
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 Cost
Measures
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 overpredict 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 Cost
for Measures in Large Office
Utility TOU / DEER Hourly avoided cost
1.4
1.3
Indoor Ltg reduction
1.2
Side Daylighting
1.1
LowSC Window on West
LowSC Window on East
1.0
Econo Maint. (retro only)
0.9
Chiller eff.
Supply Fan Motor Eff.
0.8
CHW Loop Motor Eff.
0.7
0.6
0.5
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
Preliminary conclusions
Use of IOU load shapes can under-predict and overpredict 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 Cost
for Measures in Small Retail
DEER TOU / DEER Hourly avoided cost
1.4
1.3
1.2
Ltg reduced
Pkg AC eff.
1.1
Reduce OverVent
1.0
Top Daylighting
LowSC Window on West
0.9
LowSC Window on East
0.8
LowSC Window on South
0.7
0.6
0.5
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
Preliminary conclusions
Use of IOU load shapes can under-predict and overpredict 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 Cost
for Measures in Grocery
DEER TOU / DEER Hourly avoided cost
1.4
1.2
Ltg reduced
1.0
Pkg AC eff.
Reduce OverVent
0.8
Top Daylighting
LowSC Window on West
0.6
LowSC Window on East
0.4
Zero Heat Doors
Night Covers
0.2
0.0
(0.2)
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
Preliminary conclusions
Use of IOU load shapes can under-predict and overpredict 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 Cost
for Measures in Single-Family Residential
DEER TOU / DEER Hourly avoided cost
1.4
1.3
1.2
Indoor Lighting
1.1
AC efficiency
Refg Charge
1.0
Duct Sealing
0.9
Low-E Window
Ceiling Insulation
0.8
0.7
0.6
0.5
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
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
Measure
Indoor Ltg reduction
Side Daylighting
LowSC Window on West
LowSC Window on East
Chiller eff.
Supply Fan Motor Eff.
CHW Loop Motor Eff.
2-Speed Tower
Econo Maint. (retro only)
Small Retail
Average
Difference
0.11
0.17
0.08
0.19
0.21
0.15
0.08
0.55
0.60
Grocery
Measure
Indoor Ltg reduction
Top Daylighting
LowSC Window on West
LowSC Window on East
Pkg AC eff.
Reduce OverVent
Zero Heat Doors
Night Covers
Measure
Indoor Ltg reduction
Top Daylighting
LowSC Window on West
LowSC Window on East
LowSC Window on South
Pkg AC eff.
Reduce OverVent
Average
Difference
0.10
0.15
0.16
0.20
0.18
0.24
0.50
Single Family
Average
Difference
0.05
0.18
0.15
0.18
0.37
0.48
0.34
6.87
Measure
Indoor Ltg reduction
Low-E Window
Ceiling Insulation
AC efficiency
Refg Charge
Duct Sealing
Average
Difference
0.03
0.14
0.41
0.21
0.15
0.17
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 …
when the IOU load shape follows the same
trends as the measure load shape.
1.1
1.0
0.91
0.95
0.9
DEER Measure Savings and Utility End-Use TOU Loadshapes
0.8
SCE, Office, CZ09 - Measure: Chiller Efficiency Improvement
0.7
0.6
0.5
0.4
0.3
hourly
TOU
TOU
DEER
DEER
SCE
fraction of energy savings/use during TOU period
Annual Avoided $
DEER Hourly Annual Avoided $
Ratio of Annual Avoided Cost to
DEER Hourly Avoided Cost
SCE, Office, CZ09 - Measure: Chiller Efficiency Improvement
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
Smr-On
Smr-Ptl
DEER TOU Loadshape
SCE TOU from Hourly Loadshape
Smr-Off
Wtr-On
Wtr-Ptl
Wtr-Off
SCE TOU Loadshape
fraction of annual hours in TOU period
Preliminary conclusions
But if the TOU load shape doesn’t match
the Measure load shape …
DEER Measure Savings and Utility End-Use TOU Loadshapes
0.50
Ratio of Annual Avoided Cost to
DEER Hourly Avoided Cost
SCE, Office, CZ09 - Measure: Perimeter Side Daylighting
0.40
0.30
0.20
0.10
0.00
Smr-On
Smr-Ptl
DEER TOU Loadshape
SCE TOU from Hourly Loadshape
Smr-Off
Wtr-On
Wtr-Ptl
Wtr-Off
SCE TOU Loadshape
fraction of annual hours in TOU period
Annual Avoided $
DEER Hourly Annual Avoided $
fraction of energy savings/use during TOU period
SCE, Office, CZ09 - Measure: Perimeter Side Daylighting
0.60
then the annual avoided cost
may be significantly under or
over-estimated.
1.1
0.97
1.0
0.9
0.79
0.8
0.7
0.6
0.5
0.4
0.3
hourly
TOU
TOU
DEER
DEER
SCE
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
SCE, Office, CZ09 - Measure: Economizer Maintenance
1.00
0.90
0.70
Ratio of Annual Avoided Cost to
DEER Hourly Avoided Cost
SCE, Office, CZ09 - Measure: Economizer Maintenance
0.60
0.50
0.40
0.30
0.20
0.10
0.00
-0.10
Smr-On
Smr-Ptl
DEER Hourly
Smr-Off
Wtr-On
DEER TOU
SCE TOU
Wtr-Ptl
SCE Hourly
Wtr-Off
Annual Avoided $
DEER Hourly Annual Avoided $
TOU Avoided $
DEER Hourly Annual Avoided $
0.80
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
1.21
1.05
hourly
TOU
TOU
DEER
DEER
SCE
Preliminary conclusions
And even a TOU load shape that is quite
different from the measure load shape …
DEER Measure Savings and Utility End-Use TOU Loadshapes
can lead to a “correct” answer
due to compensating errors.
0.50
0.40
Ratio of Annual Avoided Cost to
DEER Hourly Avoided Cost
PG&E, Office, CZ03 - Measure: Economizer Maintenance
0.30
0.20
0.10
0.00
Smr-On
DEER TOU Loadshape
Smr-Ptl
Smr-Off
PG&E TOU Loadshape
Wtr-On
Wtr-Ptl
Wtr-Off
fraction of annual hours in TOU period
Annual Avoided $
DEER Hourly Annual Avoided $
fraction of energy savings/use during TOU period
PG&E, Office, CZ03 - Measure: Economizer Maintenance
0.60
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
1.07
1.02
hourly
TOU
TOU
DEER
DEER
PG&E
Preliminary conclusions
Some measures do not lend themselves to be
summarized by any TOU end-use load shape:
Ratio of TOU Avoided Cost to DEER Hourly Avoided Cost
SCE, Grocery, CZ15 - Measure: Night Covers for Display Cases (medium temp)
6.00
TOU Avoided $
DEER Hourly Annual Avoided $
5.00
4.00
3.00
2.00
1.00
0.00
-1.00
-2.00
-3.00
Smr-On
Smr-Ptl
DEER Hourly
Smr-Off
Wtr-On
DEER TOU
SCE TOU
Wtr-Ptl
SCE Hourly
Wtr-Off
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.
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
DEER Measure Load Shape
PG&E, Office, CZ13 - Measure: Economizer Maintenance
0.0012
Jan
0.001
Feb
Mar
0.0008
Apr
0.0006
May
0.0004
Jun
Jul
0.0002
Aug
0
Sep
-0.0002
Oct
The hourly impact of
economizer maintenance has
little in common with the
hourly cooling profile.
Nov
-0.0004
Dec
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
PG&E Enduse Load Shape
Weekday Hour
Office, Cooling, CZ13, Weekdays
0.0008
Jan
0.0007
Feb
fraction of annual total
fraction of annual total kWh savings
0.0014
0.0006
Mar
0.0005
Apr
May
0.0004
Jun
0.0003
Jul
0.0002
Aug
Sep
0.0001
Oct
Nov
0
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
Dec
Hourly Load Shape Comparison
DEER Measure Load Shape
PG&E, Office, CZ13 - Measure: LowSC Glass on East
Jan
0.0025
Feb
0.002
Mar
Apr
0.0015
May
Jun
0.001
Jul
0.0005
Aug
The impact of low shading
coefficient glass on the
East has a much different
load shape than cooling in
general.
Sep
0
Oct
Nov
-0.0005
Dec
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
PG&E Enduse Load Shape
Weekday Hour
Office, Cooling, CZ13, Weekdays
0.0008
Jan
0.0007
Feb
fraction of annual total
fraction of annual total kWh savings
0.003
0.0006
Mar
0.0005
Apr
May
0.0004
Jun
0.0003
Jul
0.0002
Aug
Sep
0.0001
Oct
Nov
0
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
Dec
Hourly Load Shape Comparison
DEER Measure Load Shape
PG&E, Office, CZ13 - Measure: LowSC Glass on West
Jan
0.0015
Feb
Mar
Apr
0.001
May
Jun
0.0005
Jul
Aug
The impact of low
shading coefficient glass
on the West has a much
different load shape than
cooling in general.
Sep
0
Oct
Nov
-0.0005
Dec
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
PG&E Enduse Load Shape
Weekday Hour
Office, Cooling, CZ13, Weekdays
0.0008
Jan
0.0007
Feb
fraction of annual total
fraction of annual total kWh savings
0.002
0.0006
Mar
0.0005
Apr
May
0.0004
Jun
0.0003
Jul
0.0002
Aug
Sep
0.0001
Oct
Nov
0
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
Dec
demand definition
Demand Savings - kW
Demand Period
Peak Hour
Peak 9-Hour Window
Super-TOU period
Summer On-Peak Period
Demand Savings
fraction of peak hour
Peak Hour
Peak 9-Hour Window
Super-TOU period
Summer On-Peak Period
PG&E, CZ13
Large Office
Single Family
Chiller
Lighting
AC
Lighting
Efficiency Reduction Efficiency Reduction
156.1
183.4
1.23
0.072
121.9
140.9
0.97
0.049
112.6
128.0
0.85
0.050
89.6
115.6
0.56
0.049
PG&E, CZ13
Large Office
Single Family
Chiller
Lighting
AC
Lighting
Efficiency Reduction Efficiency Reduction
1.00
1.00
1.00
1.00
0.78
0.77
0.78
0.68
0.72
0.70
0.69
0.69
0.57
0.63
0.46
0.68