Solar Electric Power Association
Solar Future Arizona: A Stakeholders’ Collaboration December 11, 2008
Presented by: Joni Batson, R. W. Beck, Inc. Phil Smithers, Arizona Public Service
Copyright © 2008 by R. W. Beck, Inc. All Rights Reserved.
Overarching View of the Project
2
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Overview TECHNOLOGIES
Residential
Photovoltaics (PV)
Commercial
Photovoltaics (PV)
Daylighting Grocery, Office, Retail, School Gym, & Warehouse
Business As Usual (BAU) Market-based Adoption
Solar Water Heating (SWH)
3
DEPLOYMENT FRAMEWORKS
Targeted or Strategic Enhance Value
Conservative Optimistic Modified
Energy Capacity
Semi-Strategic Qualitative Evaluation of Near-Term Options R. W. Beck, Inc.
Methodology
4
Model solar characteristics and deployment scenarios Evaluate impacts and potential value for:
Distribution System
Transmission System
Generation/Resource Planning
Estimate financial and qualitative benefits
Solicit stakeholder feedback - 5 workshops R. W. Beck, Inc.
Summary of Preliminary Findings Impact on Peak Load Example Summer Peak Day Solar DE Max Generation at 10% of Peak 1,200
8,000
Demand Demand After Solar
243 MW Peak Reduction
Solar Resources
1,000
6,000 800 5,000
713 MW Solar Capacity
600
4,000
3,000 400 2,000
Hourly Solar DE Production (MW)
Hourly Electric System Demand (MW)
7,000
200 1,000
0
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
Hour Ending 5
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Summary of Preliminary Findings Impact on Residential Loads RESIDENTIAL TECHNOLOGIES
PV
Max. monthly production – April
SWH
Summer max. hourly output ~ 1:00 PM W-facing system oriented 18.4° summer max. hourly output ~ 2:00 PM, closer to utility peak demand period
Higher impact on residential electric consumption in winter than in summer Customer demand decreases 2%-5%
Customer demand decreases 0%-10%
Typical production not coincident with peak demand of either residence or utility Customer equipment size not impacted 6
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Summary of Preliminary Findings Impact on Commercial Loads COMMERCIAL TECHNOLOGIES
PV
During the summer a flat and 10° tilt system will have similar max. production rates During the spring, 10° tilt system will have a 10% higher max. production rate during peak production hour (1:00 PM) Customer demand decreases 0%-26% depending on business hours
Daylighting
Savings differ substantially across building types Only partially coincident with APS peak demands Customer demand decreases 1%-3% Savings decline significantly as days shorten
Typical production not coincident with peak demand of either residence or utility Customer equipment size not impacted 7
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Summary of Preliminary Findings Potential Deployment Scenarios Solar DE (Commerical and Residential Combined) 4,000,000 3,500,000 3,000,000
MWh
2,500,000 2,000,000 1,500,000 1,000,000 500,000
Optimistic
8
Conservative
RES Goal
2024
2022
2020
2018
2016
2014
2012
2010
2008
0
Modified
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Summary of Preliminary Findings Impact on Energy 400000
Annual Loss Savings (MWh)
350000 300000
Optimistic Conservative R.W. BECK
250000 200000 150000 100000 50000 0 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
9
Year
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Summary of Preliminary Findings Impact on Demand REDUCTION/DEFERRAL OF CAPACITY UPGRADES
10
Customer demand decreases 0%-26% depending on individual residential/commercial types and usages Feeder/substation/transmission equipment size not impacted Potential postponement of T & D upgrades
Requires strategic location of large amount of DE
Requires energy storage of sufficient duration
Reduced future generation expansion
R. W. Beck, Inc.
Summary of Preliminary Findings Impact on Generation Expansion Plan Example Capacity Need After Solar DE 16,000
Avoided Cap Need Future Cap Need
14,000
Renewable
Summer Peak Demand (MW)
Purchased Power CT Gas
12,000
Steam Gas CC Gas
10,000
Coal Nuclear Demand Requirements
8,000
Demand after RES
6,000
4,000
2,000
11
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
0
R. W. Beck, Inc.
Summary of Preliminary Findings Potential Utility Issues RELIABILITY AND NON-COINCIDENCE WITH PEAK LOADS
12
Increasing solar installations pushes the electric system peak to a latter hour where less capacity is available from the solar resources – limited reduction in peak capacity requirements Localized peak reduction undependable due to clouds Solar resources are non-dispatchable As they become a large portion of the power supply portfolio they reduce the available dispatchable resources to meet system contingencies – more reserves may be required R. W. Beck, Inc.
Summary of Preliminary Findings Potential Utility Issues (cont.) RELIABILITY AND NON-COINCIDENCE WITH PEAK LOADS
13
Increased cost of dispatch caused by need for additional operating reserves Increased fuel costs caused by less efficient generating portfolio – reduction of off peak low-cost base load
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Methodology/Assumptions Deployment Model
14
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Methodology/Assumptions
Customer Analysis – PV and SHW Commercial PV
Residential PV
Residential SHW
Dates
2006 & 2007
2006 & 2007
2006 & 2007
Base Case System Size
½ Peak Demand for 2006
2 kWdc
Standard electric 0.88 EF, 50-gal tank
Base Case x 1.5, 2, 2.5, 3, 3.5, 4
Sizes Analyzed Fixed Array Roof mounted Assumptions Flat roof
Roof mounted Pitched roof 18.4° elevation South facing
Baseline Usage 3,940 kWh/year (Solar) (3,485 kWh/year)
One-Axis tracking High Peak/Value (1x) N/S axis Assumptions
Roof mounted Pitched roof 18.4° elevation Southwest facing
Household Size Single-family 3-person 3 bedrooms 2 stories, 2600 sq ft
10° tilt South facing
15
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Methodology/Assumptions
Customer Analysis - Daylighting
16
Grocery (Large)
Office (Small)
Retail (Large)
School Gym
Warehouse
Size (sq ft)
30,000
6,000
50,000
6,000
100,000
Total Annual Energy Use (kWh/sq ft)
51.19
15.19
19.67
14.29
11.22
Total Peak Demand (W/sq ft)
7.95
4.64
4.71
2.71
-
Lighting Annual Energy Use (kWh/sq ft)
10.9
5.47
7.24
4.20
2.87
Lighting Peak Demand (W/sq ft)
1.59
1.50
1.61
1.20
0.90
Lighting Annual Operating Hours
6,867
3,647
4,496
3,247
-
Technology
Meets the minimum requirements for APS’s Renewable Energy Rebate Program
Light Output
Must provide ≤70% of the light output of the artificial lighting system that would otherwise be in use R. W. Beck, Inc.
Methodology/Assumptions
10th Percentile Solar Output (MW)
Solar Dependable Capacity
800 700
10th percentile Solar Output (MW) @ 5pm
600 500 400 300 200 100 0 0th
10th
20th
30th
40th
50th
60th
70th
80th
90th
100th
Percentile 2025 Conservative 2025 R.W. Beck Modified 2025 Optimistic 17
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Methodology/Assumptions Investment Deferral
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Determine an average investment cash flow as a function of peak load growth Distributed dependable capacity can essentially “slow” load growth if strategically located in a constrained area Estimate potential reduction in peak load growth due to solar DE dependable capacity Adjust for reduced losses at peak load Calculate possible deferred investment due to reduced growth R. W. Beck, Inc.
Methodology/Assumptions Investment Deferral
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Existing transmission plan covers APS’ needs through 2012 Existing distribution plan covers APS’ needs through 2010 For every 500 MW of load growth, APS needs new $110 M transmission upgrades to obtain scheduling rights for new traditional generation to growing load For every MW of load growth, APS needs new $115,000 distribution upgrades to reliably serve growing load R. W. Beck, Inc.
Methodology/Assumptions System Loss Savings
Methodology assumes:
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System resistance (R) constant through year, but, changes year to year (with buildout) System losses of about 8% per year stays constant Of this 8%, 6% is “series” losses affected by solar DE and 2% is no-load and other losses not affected
From an 8760 strip of load, 6% series losses for the year, calculate a system R (Losses = R * I2) Determine hourly load impact of 8760 strip of solar DE output for each deployment scenario Calculate hourly revised losses = R *(Iload – IsolarDE)2 R. W. Beck, Inc.
Methodology/Assumptions Business Case For Each Scenario Distribution Savings
Capacity Savings
+
Energy Savings
=
Estimated Distribution Savings
Capacity Savings
+
Energy Savings
=
Estimated Transmission Savings
Capacity Savings
+
Energy Savings
=
Estimated Generation Savings
Overall Capacity Savings
+
Overall Energy Savings
=
Estimated Total Savings
+ Transmission Savings
+ Generation Savings
= Total Savings
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R. W. Beck, Inc.
Methodology/Assumptions APS Carrying Charges
Use of carrying charges allows for calculation of annual cost savings to utility from reduced investment costs Carrying charges vary by business sector
Typically range from 9-15%
Sample calculation for 12% carrying charge: $10 million investment savings = $1.2 million per year reduction in the utility’s costs
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Preliminary Results Residential
23
SWH - Modeled 33 Customers in 7 Zip Codes over 2 Years PV - Modeled 44 Customers in 9 Zip Codes over 2 Years
SWH
PV
Annual energy reduction
10% - Max. SWH Usage
11% - 100%+ (assumes net metering)
Annual demand reduction
2% - 5%
0% - 10%
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Preliminary Results Commercial PV
PV - Modeled 23 Customers, 7 Types over 2 Years
Daylighting - Modeled 23 Customers, 3 Types over 2 Years Demand Reduction
Customer Type
PV
Distribution Centers
0% - 2.5%
Grocery
0% - 11%
Healthcare Office Bldg.
7% - 18%
Large Commercial
0% - 20%
Large Retail 2% - 26%
Realty
0% - 5%
School 24
0% - 11%
0% - 14%
Medium Retail
Storage
Daylighting
0% - 7% 0% R. W. Beck, Inc.
Preliminary Results
Feeder/Substation Screening Analysis Type of Customers
Western
11
Residential
N Phoenix - 101 & 75th Ave
Irrigation
Arrowhead 4
Region
Industrial
Location
Commercial
25
Substation
1082
Length Short
# of Customers/ Xfmr Dense
Annual Peak Demand Savings 0% - 7%
Cactus 17
Pima & Shea
Eastern
127
1
270
Cactus 18
Pima & Shea
Eastern
74
1
13
0%
Deadman Wash 2
I-17 & Deadman Wash
Central
34
1639
1% - 12%
Deadman Wash 6
I-17 & Deadman Wash
Central
East Valley-Acoma 4
N Phoenix - Scottsdale Air
Eastern
679
64
90
Short
Dense
0% - 13%
East Valley-Acoma 13
N Phoenix - Scottsdale Air
Eastern
169
5
1
Short
Dense
0% - 11%
East Valley-Cave Creek 10
N Phoenix - Cave Crk & School House Rd
Eastern
218
4
1289
Long
Sparse
0% - 6%
East Valley-Cave Creek 14
N Phoenix - Cave Crk & School House Rd
Eastern
185
7
500
Long
Sparse
0% - 15%
East Valley-Chaparral 4
N Phoenix - Shea & Scottsdale
Eastern
117
1537
Short
Dense
1% - 8%
East Valley-Chaparral 6
N Phoenix - Shea & Scottsdale
Eastern
203
2
543
Short
Dense
0% - 14%
East Valley-Chaparral 12
N Phoenix - Shea & Scottsdale
Eastern
350
4
135
Short
Dense
0% - 2%
East Valley-Thompson Peak 12 N Phoenix
Eastern
35
1356
Short
Dense
1% - 5%
Galvin Peak 41
Eastern
146
1099
Short
Dense
1% - 6%
N Phoenix - 16th & Jomax
1% - 5%
1% - 6%
7
1
1
2
Galvin Peak 42
N Phoenix - 16th & Jomax
Eastern
101
1
1063
Short
Dense
1% - 6%
Indian Bend 2
N Phoenix - Cactus & Tatum
Eastern
96
1
704
Short
Dense
0% - 5%
Indian Bend 6
N Phoenix - Cactus & Tatum
Eastern
4
Javalina 4
Bell & Sev
Western
20
Mountain View 1
N Phoenix - 99th Ave & Bell
Western
23
Pioneer 2
I-17 & Carefree
Central
226
Storage
1 3
Short
Dense
3%
1510
Short
Dense
0% - 9%
848
Short
Dense
1% - 12%
1247
0% - 9% 0%-25%
R. W. Beck, Inc.
Solar Dependable Capacity
(Includes effect of peak load shifting to 6pm) 600
Solar Output @ 10th Percentile With Adjustment for Peak Shift
Conservative Optimistic R.W. Beck Modified
500
400
300
200
100
0 2015
2017
2019
2021
2023
2025
Year 26
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Preliminary Results
Deferred Transmission Upgrades Number of Assumed 500 MW, $115 M Upgrades Deferred Through 2025 2
1
0
O
e iv
k ec .B W
at rv
tic is im pt
R.
e ns Co
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R. W. Beck, Inc.
Summary of Preliminary Findings Impact on Energy SYSTEM LOSS REDUCTION Solar DE Deployed
Annual Energy Loss Savings
GWH-Generated
GWH-Savings
Business-as-Usual Conservative Case 2010
15
2
2015
95
11 12
2025
157
19 20
Energy reduction proportional DE size, penetration
Business-as-Usual R. W. Beck Modified Case 2010
16
2
2015
161
19 21
2025
1,600
189 202
2010
16
2
2015
161
19 21
2025
3,472
390 489
Business-as-Usual Optimistic Case
28
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Qualitative Lessons Learned OBSTACLES
Misunderstanding, mythology, and opinion Limit to DE solar energy’s capacity value is regardless of quantity of PV installed/customer due to non-coincidence with customer or system peak Distribution capacity value only if
29
Strategically located (Potential in specific areas may not be adequate) Capacity value greater than one year’s growth
Optimal orientation for demand reduction has lowest energy output
No decrease in infrastructure w/o dependable storage & peak data/control
R. W. Beck, Inc.
Qualitative Lessons Learned POTENTIAL SOLUTIONS
30
Steps to shift solar output to later in day increase capacity value
Energy storage - at the expense of capital costs and loss of efficiency
Daylight savings - shift solar output one hour later
Single axis tracking - shift solar output later
Additional data/control - Expanded AMI Development in a Greenfield opportunity driven by market “pull,” not home-builder “push”
Additional research of strategic locations & teaming with builders
Public education
R. W. Beck, Inc.
Qualitative Lessons Learned ASSUMPTIONS AND LIMITATIONS
Scope evaluates average value of solar DE under differing cases and scenarios; targeted at benefits to overall average costs to consumers - methodology selected does not address the value of solar to APS' shareholders, different consumer groups and those with and without solar All results depend on the persistence of solar DE implementation; scope does not address obsolescence, renewals, and replacements. The following potential benefits are not quantified:
Possible environmental benefits
Possible societal benefits
31
Impacts from changes in various institutional factors (e.g. state mandates, various incentives, etc.) Possible future improvements in energy storage technology R. W. Beck, Inc.
Summary of Key Findings Value to APS – To Come
Example:
Demand/Capacity Savings
Energy Savings
Total Savings
Associated
Associated
Associated
MW-Savings
$ Savings
$/kW
MWh-Savings
$ Savings
$/kWh
MWh-Savings
$ Savings
$/kWh
11.300
500,000
44.25
11,300,000
600,000
0.05310
11,300,000
1,100,000
0.09735
Business-as-Usual Case 2010 2015 2025 Strategic Case 2010 2015 2025
32
R. W. Beck, Inc.
Questions?
December 11, 2008
Questions, please contact: Joni Batson, 615.431.3214,
[email protected] Phil Smithers, 602.250.4250,
[email protected] Copyright © 2008 by R. W. Beck, Inc. All Rights Reserved.
R. W. Beck, Inc.