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Solar Pathways to Lower CostSolar Pathways to Lower Cost
June, 2006June, 2006
Herb HaydenHerb HaydenPinnacle West Capital CorporationPinnacle West Capital CorporationParent company to Arizona Public ServiceParent company to Arizona Public Service
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APS Experience in APS Experience in Solar ApplicationsSolar Applications
ScottsdaleWater Campus
Carol Spring Mountain Telecom
Remote Solar Electric Service Home
Add large and small grid-tied sites
Glendale Airport
OffOff--Grid PVGrid PV--Hybrids (batteryHybrids (battery--generator)generator)
homes and rancheshomes and ranches
some larger systemssome larger systems
GridGrid--tied PV tied PV
PV rooftops, and larger groundPV rooftops, and larger ground--mountedmounted
Sites statewideSites statewide
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Not shown are APS nonNot shown are APS non--solar projects solar projects ---- Biomass, Biomass, Wind, and Hydrogen Wind, and Hydrogen Fueling StationFueling Station
Arizona
50+ PV Hybrid homes & ranches
4 Large PV Hybrids
Rooftop PV
10+ sites at 100 kW to 5+ MW
APS Solar SitesAPS Solar SitesNATURAL BRIDGES, UTAHNATURAL BRIDGES, UTAH
GRAY WOLF LANDFILLGRAY WOLF LANDFILL
YUMA ARMY PROVING YUMA ARMY PROVING GROUNDSGROUNDS
CAROL SPRING MOUNTAINCAROL SPRING MOUNTAIN
DANGLING ROPEDANGLING ROPE
SAN JUANICO, MEXICO PVSAN JUANICO, MEXICO PV--WINDWIND
FlagstaffFlagstaff
Tempe Tempe STARSTAR
GlendaleGlendale
GilbertGilbert
YumaYuma
EmbryEmbry
ScottsdaleScottsdale
ADEQADEQ
PrescottPrescott
SaguaroSaguaro
More...More...
MARBLE CANYONMARBLE CANYON
LOWELL OBSERVATORYLOWELL OBSERVATORY
ST MICROST MICRO
SAN LUISSAN LUIS
SCOTTSDALE WATER CAMPUSSCOTTSDALE WATER CAMPUS
PRESCOTT AIRPORTPRESCOTT AIRPORT
GILBERT NATURE CENTERGILBERT NATURE CENTER
GLENDALE AIRPORTGLENDALE AIRPORT APS STAR FACILITYAPS STAR FACILITY
YUCCA POWER PLANTYUCCA POWER PLANT
AZ DEPT ENV QUALITYAZ DEPT ENV QUALITY
SAGUARO SOLAR SAGUARO SOLAR TROUGHTROUGH
EMBRY RIDDLE AERO UNIVEMBRY RIDDLE AERO UNIV
FLAGSTAFF SERVICE CENTERFLAGSTAFF SERVICE CENTER
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Many Solar Many Solar OptionsOptions
Rooftop Tilted PV (APS at Tempe Recycling Center)
Tracking PV and Concentrator PV(APS STAR in Tempe)
Large Solar Thermal Trough Plant (California)
Tracking PV(APS at Embry Riddle University)
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Need for More SolarNeed for More Solar
Southwestern US goals would require thousands of MW Southwestern US goals would require thousands of MW
Rooftop PV option is currently supported by utility Rooftop PV option is currently supported by utility rebates programs, customer ownedrebates programs, customer owned
Higher output & lower costs are needed for solar to Higher output & lower costs are needed for solar to become a more significant resourcebecome a more significant resource
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Technology Benefits at Larger ScaleTechnology Benefits at Larger Scale
More solar technology options, efficiencies of More solar technology options, efficiencies of scalescale
Greater energy Greater energy ““yieldyield”” (output kWh per installed (output kWh per installed kW)kW)
ThermalThermal--electric solar options electric solar options ---- energy storage energy storage and gas backupand gas backup
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Location and Tracking Affect ResourceLocation and Tracking Affect Resource
50%
75%
100%
125%
150%
FixedHorizontal
Fixed Latitude TrackingHorizontal
Concentrators TrackingLatitude
Daggett
PrescottPhoenixTucson
Phoenix PVFixed, Tilted used as Baseline
88%
132%
123% 123%
More energy output from More energy output from ““trackingtracking”” the sunthe sun
“PV Tracker” systems --more energy per kW
Fixed, Horizontal
From NREL Redbook data.
PV rated at 1000 W/m2, CPV rated at 850 W/m2 DNI.
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60%
70%
80%
90%
100%
110%
120%
130%
- 20 40 60 80 100 120 140 160 180 200Cell Rating/Operating Temp F
Concentrating PV
Phoenix in JuneTypical temperature rise of PV cell under full sun is 47 F if back is open to air. If back is foam insulated, temperature rise of 81 F is observed.
Standard PV
Phoenix in June
Phoenix in December
Phoenix in June on Insulated Roof Tiles
Over 1/3 power loss due to heat
Heat and Cold Affect EfficiencyHeat and Cold Affect Efficiency
Phoenix in December
Heat decreases PV output, severely in some casesHeat decreases PV output, severely in some cases
Concentrators are affected less by temperatureConcentrators are affected less by temperature
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Tracking for Flat Plate and ConcentratorsTracking for Flat Plate and Concentrators
SingleSingle--axis Tracking PV axis Tracking PV systems provide about 20% systems provide about 20% more energy in sunny locationsmore energy in sunny locations
Solar trough systems also use Solar trough systems also use singlesingle--axis tracking to enable axis tracking to enable sunlight concentrationsunlight concentration
High concentration systems High concentration systems such as CPV require 2such as CPV require 2-- axis axis trackingtracking
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APS Prescott Airport Solar SiteAPS Prescott Airport Solar Site
3,400 kW currently, of over 6 MW planned3,400 kW currently, of over 6 MW planned
Large tracking PV arrays, and new CPV systemsLarge tracking PV arrays, and new CPV systems
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Summer PV Output ComparisonSummer PV Output ComparisonJuly 21, 2004
16%
32%
11%
27%
41%
67%
49%55%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
3:00 AM 6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM 9:00 PM
5 PM
6 PM
Fixed Horizontal
Fixed Tilted
Tracking PV
CPV
Highest Summer Load Hours
Tracking PV provides higher capacity late in the dayTracking PV provides higher capacity late in the day
Systems shown are in Phoenix area, using DC PV ratingsSystems shown are in Phoenix area, using DC PV ratings
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Winter PV Output ComparisonWinter PV Output ComparisonJanuary 8, 2004
36%
59%
56%
66%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM
Fixed Horizontal
Fixed Tilted
Tracking PV
CPV
CPV and Tilted installations have highest winter peaksCPV and Tilted installations have highest winter peaks
Output from Horizontal PV systems is much reducedOutput from Horizontal PV systems is much reduced
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2003 Solar Results 2003 Solar Results ---- Energy per kW RatingEnergy per kW Rating
60%
80%
100%
120%
140%
Desert
Challenger
GilbertNAU
Tempe R
ecycle
Scotts
dale Park
ing
ST Micr
o Roofto
p
STAR Park
ingMTA2MTA3YumaGilb
ertGlen
daleOPV1
Scotts
dale Eas
t
Scotsd
ale West
ERAUW1 W3 E1 E2 E3 E4 E5 G2 G3
Fixed Latitude PV --used as 100% reference
Horizontal resource --88%
Tracking resource --123% Tracking PV
Fixed Horizontal PV
CPV
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$8,300
7500
$5,500
9500
$/KWdc 5yr kWh
Retail Fixed PV
Large PV Tracker
Net Cost Result5-yr. kWh per $
0.9
1.7
RetailFixed PV
Large PVTracker
PV Energy Cost ComparisonsPV Energy Cost Comparisons
Nearly twice the energy Nearly twice the energy per dollar from solar at per dollar from solar at larger scalelarger scale
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Concentrators Concentrators –– Where They FitWhere They FitM
atur
e C
ost P
oten
tial
Minimum Installation Size
CPVDish
Solar Trough (CSP)
PVNow over 1000 MW/yr.
New Solar Concentrators
LowLow--cost potential, at moderate volumecost potential, at moderate volume
Require sunny climates, MW scaleRequire sunny climates, MW scale
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APS 1 MW Solar Electric TroughAPS 1 MW Solar Electric Trough
First First solar trough since 1992solar trough since 1992
First ever at 1 MW size First ever at 1 MW size ----helpful for markethelpful for market--entry and entry and remote useremote use
Water cooling usedWater cooling used
Thermal storage & fuel Thermal storage & fuel backup can be addedbackup can be added
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1 MW Organic 1 MW Organic RankineRankine Cycle TurbineCycle TurbinePentane working fluid, water cooledPentane working fluid, water cooled
Not as efficient as larger steam systems, but proven with Not as efficient as larger steam systems, but proven with geothermal plantsgeothermal plants
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Concentrating PV TechnologyConcentrating PV Technology140 kW Amonix Field
(APS STAR in Tempe)
Good for sunny regions, like US southwest
High efficiency PV cells -- 26% with silicon
500 kW installed by APS
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Concentrating Sunlight Concentrating Sunlight Dramatically Reduces Cell SizeDramatically Reduces Cell Size
-50
0
50
100
150
200
250
Wat
ts A
C pe
r 6" w
afer
Conventional PV WafersAmonix PV Wafers
Size indicatesthe PV cell size for same power
(this is Amonix)
(this is Regular PV)
300 times more energy per cell area than regular PV300 times more energy per cell area than regular PV
Higher concentration and higher efficiency will lower costsHigher concentration and higher efficiency will lower costs
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CPV ManufacturingCPV Manufacturing
USUS--made PV Cells, lenses, tracker made PV Cells, lenses, tracker structure, controlsstructure, controls
$4/W possible at 10 MW per year $4/W possible at 10 MW per year
Under $3/W is possible with future Under $3/W is possible with future efficiency gainsefficiency gains
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CT/Spectrolabs Microdish(APS STAR in Tempe)
New New MultiMulti--Junction CPVJunction CPV
World’s First Grid-Tied High Concentration Multi-junction PV
Advanced “space” cells -- same as used on Mars Rovers
Can reach 33% efficiency or more
Development with Spectrolabs, Concentrating Technologies and National Renewable Energy Lab
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Need for Larger Scale SolarNeed for Larger Scale Solar
Solar appears to be the only option to meet large scale Solar appears to be the only option to meet large scale renewables goals renewables goals
US incentives today are primarily US incentives today are primarily ““customercustomer--onlyonly”” –– a major a major barrier to substantial solarbarrier to substantial solar
In Europe, 50c/kwh premium for solar energy is profitable and In Europe, 50c/kwh premium for solar energy is profitable and driving large scale solar investmentdriving large scale solar investment
Concentrating resource in US southwest is excellent Concentrating resource in US southwest is excellent ––immediate cost potential of under 20c/kWh, possibly 10c/kWh immediate cost potential of under 20c/kWh, possibly 10c/kWh with time and investmentwith time and investment
Arizona State University 30kW PV System on Parking Structure -- Provides Power to Supplement Daytime Lighting of Parking Structure
Yavapai-Apache Nation30kW PV System on Parking Structure
City of Rohnert Park, CA30kW PV System on Roof of Sports Center Complex
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PV Projects in ProgressPV Projects in Progress
•• Northern Nevada Correctional Center: 30kW Mounted on Roof of NewNorthern Nevada Correctional Center: 30kW Mounted on Roof of NewBiomass Facility (also in progress)Biomass Facility (also in progress)
•• City of Flagstaff, AZ: 15kW Mounted on Covered Entryway and WallCity of Flagstaff, AZ: 15kW Mounted on Covered Entryway and Walls s
•• Design and Construct Solar Hybrid Project (100 kW) to Provide PoDesign and Construct Solar Hybrid Project (100 kW) to Provide Power wer to a Remote Region at the Western Edge of the Grand Canyon for tto a Remote Region at the Western Edge of the Grand Canyon for the he HualapaiHualapai Tribe Tribe