Southwest Solar Technologies, Inc. ASSETS FOR COLLABORATION IN CONCENTRATING SOLAR Herb Hayden, CTO

Southwest Solar Technologies, Inc. ASSETS FOR COLLABORATION IN CONCENTRATING SOLAR Herb Hayden, CTO

Southwest Solar Technologies Phoenix-based technology company developing efficient, no-water-use solar concentrator systems for distributed utility applications in desert regions 2

Southwest Solar Research Park SST headquarters on 18-acre industrial site Central Phoenix, near Sky Harbor International Airport, I-10 Collaborative testing for the advancement of renewable energy technologies for desert regions 3

Operations Secured urban location for year round sunshine/testing 1 MW Grid interface (SRP) and natural gas service (SWG) Solar meteorological station (NREL SOLRMAP) and data collection Office & conference space, high speed internet Prototype machine shop fabrication and electronics lab 4

Activities Specialized solar facility open for third party test and demonstrations Advanced design and analysis software platforms (CAD/FEA/CAM) Prototype manufacturing facilities Electronics and controls laboratory Development of SST dish, CPV and dish-thermal technology 5

Solar Dish Concentrator World s largest commercial solar dish 320 square meters 250 kw output - light and heat > 2000 suns solar flux Point focus - 0.5 meter dia. aperture Sun tracking accuracy 0.1 degree 6

Applications Micro turbine - Air- Cycle with hybrid fuel capability Concentrated Photovoltaic (CPV) Direct thermal applications such as industrial process heat and steam 7

Core Competencies Optics (Zemax and in-house custom software) Structures / Mechanical Engineering (Siemens NX, SolidWorks) Thermodynamics Electronics, Software and Controls Turbo Machinery Concentrating Photovoltaics 8

Mirror Facets < 1 mrad RMS 9 9

Dish CPV Optical Model Siemens NX with Point Source Flux model of dish and CPV array surface in Siemens NX, with sun as point source Facilitates initial studies of design alternatives 10

Projected Vertical Position (in) Flux Prediction with Sun Convolution Requires Processing External to NX Flux Prediction with NX +Sun Shape +Slope Error -20 25-15 -10 20-5 0 5 10 15 10 Flux W/cm 2 15 20 5-20 -15-10 -5 0 5 10 15 20 Projected Horizontal Position (in) 0 Sun shape and mirror errors modeled by external SST calculation in MatLab, and re-importing to NX 11

Mirror Testing SST is developing optical deflectometry measurement to assess shape, focal distance and accuracy, and to identify problem areas 12

SST Dish- Turbine Solar Receiver High temperature air is the heat transfer fluid (no water) Turbine Engine Recuperated design High speed alternator 1. Atmospheric air is compressed in Compressor stage 2. Pressurized air travels through Heat Exchanger (recuperator) to preheat using turbine exhaust 3. Heated pressurized air superheated in the solar receiver from dish concentrator sunlight. Combustor provides option to use fuel for heat when solar power is unavailable. 4. Hot pressurized air drives turbine, rotates generator, producing electrical power, and drives the compressor 5. Exhaust travels through heat exchanger and heat is recovered 6. Air is discharged at a temperature only slightly warmer than ambient 13

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Southwest Solar - Modular CPV for Dish Modular CPV Receiver - for Dish as well as Tower systems A departure from previous designs Tolerant to flux variation limitation of existing CPV Liquid cooling Low cost to manufacture Benefits Tolerant to hot climates, indifferent to altitude Byproduct heat available for customer use Energy gain by tracking (30% over regular PV) For use with dish and tower collectors 15

SST CPV - Modular Approach for Dishes Designed for Dish and Tower systems A departure from previous designs Tolerant to flux variation limitation of existing CPV Liquid cooling Low cost to manufacture Benefits Tolerant to hot climates Indifferent to altitude Byproduct heat available for customer use Energy gain by tracking (30% over regular PV) Adaptable to a variety of dish and tower collectors SST CPV Module - Aperture View DC Combining, Boost and Control 16

Example - Utility Scale 50 kw Dish CPV CPV Array dome Inverter and radiator integrated on-dish structure CPV Array Inverter Radiator/Fans/Pumps 17

Dish Scalability for CPV / Thermal SST dish/mirror is adaptable to range of sizes and shapes Mirror shapes can be rectangular, square, gore sections, triangles CPV and thermal applications Heat can offset fuel/electricity for Water heating Brine evaporation Water distillation, Membrane Distillation Process heat Steam pre-heating Thermal air conditioning 18

Test Tracker Smaller scale testing 19

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