Transcript Direct Use of Natural Gas Status of Analysis Staff Analysis Today’s Agenda: Review of Major Analytical Input Assumptions Present Preliminary Results (Not Findings!) March 18,

Direct Use of Natural Gas
Status of Analysis Staff Analysis
Today’s Agenda:
Review of Major Analytical Input Assumptions
Present Preliminary Results (Not Findings!)
March 18, 2011
Today’s Results =
Status Report, Not Final Answer
We Aren’t Testing Every Option
 We Haven’t Tested Alternative
Input Assumptions
 We Haven’t Adjusted the
Conservation Resource Potential
for the impact of conversions to or
from electricity to natural gas

We Aren’t Testing Every Option

Some conversion options are excluded
– Electric zonal to Electric FAF
» Reason: Conversion cost more and uses more
– Electric or Gas FAF to Ductless Heat Pumps
» Reason: Assuming consumer preference is to use
existing central system
– Conversion to “dual fuel” systems (i.e., heat pump
with gas furnace)
» Reason: While this is the “optimal” solution if
“cross-over” temperature between heat pump and
gas furnace is determined by current relative fuel
prices, the technology is not available to
implement this option (Smart Grid (or Google,
Apple?) may enable this)
We Will Test Additional
Scenarios


The “benefits/value” of providing air
conditioning when converting to a heat pump
are set to $0.
Energy use and cost are based on “market”
quality installation, not utility/ETO program
requirements
– Duct systems are not assumed to be sealed at time
of installation
– No heat pump controls/commissioning is assumed
– Name plate furnace & heat pump efficiencies are set
at federal minimums

With your guidance/input we intend to test
alternative assumptions
Conservation Measures
Affected by Conversions
Dishwasher
1,600
Clothes Washer
1,400
GFX
1,200
HPWH
1,000
Efficient DHW Tanks
800
Showerheads
600
HVAC HP Upgrade - Existing SF
400
HVAC HP Conversion - Existing SF
200
HVAC Supplement (DHP) - Existing SF
-
<0
<10
<20
<30
<40
<50
<60
<70
<80
<90
<100
<110
<120
<130
<140
<150
<160
<170
<180
<190
<200
>200
Achievable Potential (MWa by 2030)
1,800
TRC Levelized Cost (2006$/MWH)
ResWX MF
ResWX SF
HVAC and DHW System
Conversion Cost and Energy
Use Assumptions
Space Conditioning Estimates



Source: SEEM calibrated simulation results
from weatherization and heat pump
conversion/upgrade analysis
Gas consumption assumes identical model
input assumptions as electric forced air,
adjusted for furnace conversion efficiency
(AFUE 90%)
Climate = PNW Weighted Average
– Should we do each heating zone analysis
after initial results are reviewed?
Water Heating Use Estimates

Source: DOE Water Heater Standard’s
Rulemaking Life Cycle Cost and Payback
Period Analytical Spreadsheets
(http://www1.eere.energy.gov/buildings/appliance_standards/residential/water_pool_heaters_nopr_tools.html)

PNW average daily hot water assumptions
used in lieu of DOE test procedure values:
– < 55 gal tanks: 56 gal/day for SF & 38 gal/day MF
– >55 gal tanks 64.4 gal/day for SF

Gas system use assumes same input
assumptions as electric resistance
Home Sized Revised to Reflect Correlation
with System Types and Basements*
Dwelling Type
Multifamily
Multifamily
Single Family
Single Family
*Source: PNRES92
System Type
Basement
(sq.ft.)
No Basement
(sq.ft.)
Electric Zonal
N/A
Gas or Electric
FAF & Heat
Pumps
N/A
1050
Electric Zonal 1900
Gas or Electric
FAF & Heat
Pumps
2250
1500
1450
1900
Base Case Energy Use Assumptions
– Space Heating
Home Characteristic
Dwelling
Type
System Type
Ductless
Zonal
House Size
HP*
Electric FAF Electric Heat Pump Gas FAF
Basement
(sq.ft.)
(kWh/yr) w(kWh/yr) (kWh/yr) (kWh/yr) (MMbtu/yr)
MF
No
1050
1,774
3,042
2,943
1,774
11.28
MF
No
1450
3,551
6,477
5,919
4,471
24.03
SF
No
1500
4,252
8,120
7,086
5,286
30.12
SF
No
1900
5,814
11,182
9,690
6,874
41.48
SF
Yes
1900
5,039
9,297
8,399
5,741
34.49
SF
Yes
2250
5,692
10,245
9,486
6,094
38.01
*Ductless Heat Pump Use Assumed to be 60% of Zonal Electric. This Assumption Results
In Lower Use Than Air Source Heat Pump w/o Duct Sealing & System Commissioning.
Base Case Energy Use Assumptions
– Space Cooling
Home Characteristic
Dwelling
Type
System Type
Ductless
House Size HP*
Basement (sq.ft.)
(kWh/yr)
Zonal
Electric
Electric
FAF w/CAC w/CAC
(kWh/yr) (kWh/yr)
Gas FAF
Heat Pump w/CAC
(kWh/yr) (kWh/yr)
MF
No
1050
377
415
415
415
415
MF
No
1450
394
432
432
432
432
SF
No
1500
429
470
470
470
470
SF
No
1900
527
578
578
578
578
SF
Yes
1900
416
456
456
456
456
SF
Yes
2250
401
440
440
440
440
*Ductless Heat Pump Cooling Use is Lower Than Central AC or Air Source Heat Pump
DHP’s are assumed to achieve SEER 14 vs SEER 13 for Central AC & Heat Pumps.
Space Conditioning System
Cost (2009$)
Home Characteristic
System Type
Dwelling
House Size Ductless
HP
Type
Basement (sq.ft.)
Electric
FAF
w/CAC
Electric
FAF
Zonal
Electric
w/CAC
Zonal
Electric
Heat
Pump
Gas FAF
w/CAC
Gas FAF
MF
No
1050
$3,668
$2,131
$803
$2,073
$746
$4,213
$4,256
$2,929
MF
No
1450
$3,668
$2,131
$855
$2,357
$1,030
$4,292
$4,256
$2,929
SF
No
1500
$3,668
$2,131
$855
$2,392
$1,065
$4,292
$4,306
$2,951
SF
No
1900
$4,584
$2,319
$900
$2,676
$1,349
$4,621
$4,505
$2,990
SF
Yes
1900
$4,126
$2,159
$900
$2,676
$1,349
$4,621
$4,505
$2,990
SF
Yes
2250
$4,584
$2,318
$938
$2,925
$1,598
$5,237
$4,505
$2,990
Ductless Heat Pumps are assumed to have lower installed
cost than air source heat pumps, independent (i.e.,
excluding ) of the cost of duct systems.
Space Conditioning O&M Cost
(2009$)
Home Characteristic
Dwelling
Type
System Type
Gas &
House Size Ductless
Electric
Basement
(sq.ft.)
HP
FAF w/CAC
Gas &
Electric
FAF
Zonal
Electric
w/CAC
Zonal
Electric
Heat Pump
MF
No
1050
$142
$183
$47
$136
$0
$148
MF
No
1450
$142
$183
$47
$136
$0
$148
SF
No
1500
$142
$183
$47
$136
$0
$148
SF
No
1900
$142
$183
$47
$136
$0
$148
SF
Yes
1900
$142
$183
$47
$136
$0
$148
SF
Yes
2250
$142
$183
$47
$136
$0
$148
Duct System Cost (2009$)
Dwelling Type
Basement
House Size
(sq.ft.)
Duct System
Cost
MF
No
1050
$1,467
MF
No
1450
$2,025
SF
No
1500
$2,181
SF
No
1900
$2,962
SF
Yes
1900
$2,480
SF
Yes
2250
$2,721
Water Heating System Cost
& Use Assumptions
Dwelling Tank Size
Type
(gals)
System Type
Total Installed
Cost (2009$)
Annual
Annual Energy
Maintenance Use - Electricity
Cost (2009$)
(kWh)
Annual Energy
Use - Gas
(MMbtu)
SF
X<=55
Electric Resistance
$751
$4
3,355
-
SF
X<=55
HPWH
$1,589
$9
1,594
-
SF
X<=55
Gas Tank
$1,178
$12
-
17.3
SF
X<=55
Condensing Gas
$1,861
$15
116
9.2
SF
X<=55
Instant Gas
$2,380
$67
30
13.2
SF
X>55
HPWH
$1,623
$9
1,830
-
SF
X>55
Condensing Gas
$2,084
$15
134
15.8
SF
X>55
Instant Gas
$2,380
$67
30
15.1
MF
X<=55
Electric Resistance
$751
$4
2,295
-
MF
X<=55
Gas Tank
$1,178
$12
-
11.8
MF
X<=55
Instant Gas
$2,380
$67
28
9.0
MF
X<=55
Condensing Gas
$1,861
$15
116
9.2
MF
X<=55
HPWH
$1,589
$9
1,090
-
Base Case Water Heating
Assumptions
System Type
Total
Installed
Cost
Representative Model
SF - Electric Storage
<= 55 gal
50 gal EF 0.95 – Electric Resistance
SF - Electric Storage >
55 gal
66 gal EF 2.00 - Heat Pump Water Heater
SF - Gas Storage <=
55 gal
40 gal EF 0.63 EF - Standing Pilot
SF - Gas Storage > 55
gal
66 gal EF 0.77 EF – Condensing w/ power vent
Variable output EF 0.82 Electronic Ignition, Power
SF - Gas Tankless
Vent, Improved HX
MF - Electric Storage
<= 55 gal
40 gal EF 0.95 Electric Resistance
MF - Gas Storage <=
55 gal
30 gal EF 0.63 EF - Standing Pilot
Variable output 0.82 EF Electronic Ignition, Power
MF - Gas Tankless
Vent, Improved HX
Annual
Annual
Energy
Energy
Annual
Use Use Maintenance Electricity
Gas
Cost
(kWh)
(Mbtu)
$
751
$
4.01
3,355
$
2,176
$
8.89
1,594
$
1,178
$
12.36
-
17.69
$
3,178
$
14.79
128
13.69
$
2,380
$
66.88
30
13.16
$
617
$
4.01
2,277
$
1,071
$
14.79
-
12
$
2,380
$
66.88
28
8.91
Next Steps
Revise inputs per guidance provided today
 Adjust conservation “supply curves” to
reflect changes in electric/gas “units” due to
conversions
 Re-run RPM
 Consider “customer perspective” (i.e.,
review economics of conversion from end
users perspective using retail gas and
electric rates
