Solar Pathways to Lower Cost

Transcription

1 Solar Pathways to Lower Cost June, 2006 Herb Hayden Pinnacle West Capital Corporation Parent company to Arizona Public Service 1

2 Carol Spring Mountain Telecom Remote Solar Electric Service Home APS Experience in Solar Applications Off-Grid PV-Hybrids (battery-generator) homes and ranches some larger systems Grid-tied PV PV rooftops, and larger ground-mounted Sites statewide Scottsdale Water Campus Glendale Airport Add large and small gridtied sites 2

3 APS Solar Sites 50+ PV Hybrid homes & ranches 4 Large PV Hybrids Rooftop PV 10+ sites at 100 kw to 5+ MW Not shown are APS non- solar projects -- Biomass, Wind, and Hydrogen Fueling Station EMBRY RIDDLE AERO UNIV Arizona GRAY WOLF LANDFILL GLENDALE AIRPORT AZ DEPT ENV QUALITY YUCCA POWER PLANT YUMA ARMY PROVING GROUNDS SAN LUIS SAN JUANICO, MEXICO PV- WIND MARBLE CANYON NATURAL BRIDGES, UTAH DANGLING ROPE LOWELL OBSERVATORY FLAGSTAFF SERVICE CENTER PRESCOTT AIRPORT CAROL SPRING MOUNTAIN ST MICRO SCOTTSDALE WATER CAMPUS APS STAR FACILITY GILBERT NATURE CENTER SAGUARO SOLAR TROUGH Flagstaff Tempe STAR Glendale Gilbert Yuma Embry Scottsdale ADEQ Prescott Saguaro More... 3

4 Many Solar Options Rooftop Tilted PV (APS at Tempe Recycling Center) Tracking PV (APS at Embry Riddle University) Tracking PV and Concentrator PV (APS STAR in Tempe) Large Solar Thermal Trough Plant (California) 4

5 Need for More Solar Southwestern US goals would require thousands of MW Rooftop PV option is currently supported by utility rebates programs, customer owned Higher output & lower costs are needed for solar to become a more significant resource 5

6 Technology Benefits at Larger Scale More solar technology options, efficiencies of scale Greater energy yield (output kwh per installed kw) Thermal-electric electric solar options -- energy storage and gas backup 6

7 APS STAR Site -- Solar Test & Research 7

8 Location and Tracking Affect Resource 150% 125% 100% Phoenix PV Fixed, Tilted used as Baseline 123% 123% 132% Daggett Tucson Phoenix Prescott PV Tracker systems -- more energy per kw 75% 88% Fixed, Horizontal From NREL Redbook data. PV rated at 1000 W/m2, CPV rated at 850 W/m2 DNI. 50% Fixed Horizontal Fixed Latitude Tracking Horizontal Concentrators Tracking Latitude More energy output from tracking the sun 8

9 Heat and Cold Affect Efficiency 130% 120% 110% 100% 90% Standard PV Phoenix in December Concentrating PV Phoenix in June Phoenix in December Over 1/3 power loss due to heat 80% Phoenix in June 70% Typical temperature rise of PV cell under full sun is 47 F if back is open to air. If back is foam Phoenix in June on insulated, temperature rise of 81 F is observed. Insulated Roof Tiles 60% Cell Rating/Operating Temp F Heat decreases PV output, severely in some cases Concentrators are affected less by temperature 9

10 Tracking for Flat Plate and Concentrators Single-axis Tracking PV systems provide about 20% more energy in sunny locations Solar trough systems also use single-axis tracking to enable sunlight concentration High concentration systems such as CPV require 2-2 axis tracking 10

11 APS Prescott Airport Solar Site 3,400 kw currently, of over 6 MW planned Large tracking PV arrays, and new CPV systems 11

12 APS Single Axis Tracker Multi-megawatt Field 12

13 Summer PV Output Comparison 100% 90% July 21, 2004 Highest Summer Load Hours 80% Tracking PV 5 PM 6 PM 70% CPV 67% 60% 50% Fixed Horizontal 55% 49% 40% Fixed Tilted 41% 30% 32% 27% 20% 16% 10% 11% 0% 3:00 AM 6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM 9:00 PM Tracking PV provides higher capacity late in the day Systems shown are in Phoenix area, using DC PV ratings 13

14 Winter PV Output Comparison 100% 90% January 8, % 70% CPV 66% 60% 50% 56% Fixed Tilted 59% Tracking PV 40% 30% Fixed Horizontal 36% 20% 10% 0% 6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM CPV and Tilted installations have highest winter peaks Output from Horizontal PV systems is much reduced 14

15 2003 Solar Results -- Energy per kw Rating 140% 120% Tracking resource % Tracking PV CPV 100% Fixed Latitude PV -- used as 100% reference Horizontal resource -- 88% 80% Fixed Horizontal PV 60% 15 Desert Challenger Gilbert NAU Tempe Recycle Scottsdale Parking ST Micro Rooftop STAR Parking MTA2 MTA3 Yuma Gilbert Glendale OPV1 Scottsdale East Scotsdale West ERAU W1 W3 E1 E2 E3 E4 E5 G2 G3

16 PV Energy Cost Comparisons Retail Fixed PV Large PV Tracker $8, Net Cost Result 5-yr. kwh per $ 1.7 Nearly twice the energy per dollar from solar at larger scale 7500 $5, $/KWdc 5yr kwh Retail Fixed PV Large PV Tracker 16

17 Concentrators Where They Fit Mature Cost Potential PV Now over 1000 MW/yr. CPV Dish Minimum Installation Size New Solar Concentrators Solar Trough (CSP) Low-cost potential, at moderate volume Require sunny climates, MW scale 17

18 APS 1 MW Solar Electric Trough First solar trough since 1992 First ever at 1 MW size -- helpful for market-entry entry and remote use Water cooling used Thermal storage & fuel backup can be added 18

19 APS Saguaro Solar Trough Field (1 MW ORC) 19

20 1 MW Organic Rankine Cycle Turbine Pentane working fluid, water cooled Not as efficient as larger steam systems, but proven with geothermal plants 20

21 Solar Trough ORC Schematic 21

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23 ORC Control Monitor Display 23

24 Dish Stirling SAIC with STM at APS 24

25 SES at Sandia Labs 25

26 Concentrating PV Technology 140 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 26

27 Concentrating Sunlight Dramatically Reduces Cell Size Watts AC per 6" wafer (this is Amonix) Size indicates the PV cell size for same power (this is Regular PV) Conventional PV Wafers Amonix PV Wafers 300 times more energy per cell area than regular PV Higher concentration and higher efficiency will lower costs 27

28 CPV Manufacturing US-made PV Cells, lenses, tracker structure, controls $4/W possible at 10 MW per year Under $3/W is possible with future efficiency gains 28

29 CT/Spectrolabs Microdish (APS STAR in Tempe) New Multi-Junction 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 29

30 Need for Larger Scale Solar Solar appears to be the only option to meet large scale renewables goals US incentives today are primarily customer-only a major barrier to substantial solar In Europe, 50c/kwh premium for solar energy is profitable and driving large scale solar investment Concentrating resource in US southwest is excellent immediate cost potential of under 20c/kWh, possibly 10c/kWh with time and investment 30

31 Yavapai-Apache Nation 30kW PV System on Parking Structure Arizona State University 30kW PV System on Parking Structure -- Provides Power to Supplement Daytime Lighting of Parking Structure City of Rohnert Park, CA 30kW PV System on Roof of Sports Center Complex

32 PV Projects in Progress Northern Nevada Correctional Center: 30kW Mounted on Roof of New Biomass Facility (also in progress) City of Flagstaff, AZ: 15kW Mounted on Covered Entryway and Walls Design and Construct Solar Hybrid Project (100 kw) to Provide Power to a Remote Region at the Western Edge of the Grand Canyon for the t Hualapai Tribe 32