Peltier Solar Concentrator

1. Peltier Solar Concentrator By: Michael Forrest Kyle Fifield Evan White

2. The Problem • To demonstrate that a thermoelectric device can efficiently converted solar energy into electricity. • The goal is to create a system at least as efficient as PV panels.

3. The Solution • Satellite Dish Solar Concentrator • Hi-Z HZ-20 Thermoelectric Module • Aluminum Collector Plate • Time-Based Solar Coordinate Tracking • Battery Storage • LCD User Interface

4. What is a Thermoelectric Device? • In a thermoelectric device, a voltage is created when a difference in temperature exists across the device. • By heating one side of the device and sinking heat from the other side, an electric voltage will be created. + -

5. Sun System Diagram Solar Rays Solar Concentrator H-Bridge Circuit Horizontal Tilt Microcontroller Thermoelectric Device Collector Plate Dc/Dc Step-up Azimuth Rotation

6. Solar Tracking Subsystem • Real-Time Clock (DS1307) • User interface with Buttons and LCD Screen • Microcontroller (Coldfire) • Motor Controller (H-Bridge) • DC Motor with Potentiometer (Azimuth) • Linear Actuator with Accelerometer (elevation)

7. H-Bridge Circuit H-Bridge Circuit Motor Linear Actuator Coldfire Microcontroller Time of Day Sensor Potentiometer Accelerometer LCD Display and User Interface Solar Tracking System Diagram

8. Solar Tracking Positioning Equations elevation (zenith) Angle: Azimuth Angle : is the solar elevation is the hour angle of the present time is the current sun declination is the local latitude is the azimuth angle h • Inputs • Date and Time • Latitude

9. Microcontroller Code if (one_minute_has_passed (old_minutes, RcvClock[1])) { old_minutes = RcvClock[1]; //Makes certain that the old time is equal to the last RcvClock it used// //All Calculations// elevation_angle = calculate_elevation(); azimuth_angle = calculate_azimuth(); measure_feedback(); //Move the Motors// move_azimuth_motor(azimuth_angle); move_elevation_actuator(elevation_angle); }

10. Sun System Diagram Solar Rays Solar Concentrator H-Bridge Circuit Horizontal Tilt Microcontroller Thermoelectric Device Collector Plate Azimuth Rotation

11. Mechanical Azimuth Tracking

12. Elevation Tracking Highest Sun Elevation (70⁰) Lowest Sun Elevation (12⁰) 70⁰ 12⁰ 6 inch Stroke Solar Concentrator Linear Actuator

13. Thermoelectric Collector Plate Mount • Purpose: • Maximize Performance and Power Efficiency of HZ-20. • HZ-20 Module Around 5% Efficient. • Design Aspects: • Minimum Load of 200 psi on HZ-20. • Thermal Expansion of HZ-20. • Efficient Heat Transfer • Keeping Cold Side of HZ-20 Cool.

14. Subsystem Diagram of Thermoelectric Mount Belleville Springs Heat Sink Cool Side Hot Side Thermoelectric Device Collector Plate Solar Rays

15. Loading on HZ-20 Module • Ensures Module Remains in Compression to Maximize Heat Transfer. • Solution: • Belleville Springs. • Apply Large Amount of Force in Compact Area. • Also Allows for Thermal Expansion.

16. Load and Thermal Expansion Calculations Thermoelectric Device Dimensions Force Calculation Load Required: 200 psi* Thermal Expansion Calculation Where: = Change in Length = Thermal Expansion* = Change in Temp. = Initial length *Information Given from Specification Sheets

17. Efficient Heat Transfer • Thermal Grease: • Ensures Efficient Heat Transfer from Mount to HZ-20 and HZ-20 to Heat Sink. • Overhang of 0.5 Inches and 0.25 Inches of Thickness on Mount: • Ensures Uniform Heating on HZ-20.

18. Thermal Resistance Diagram TBar Temperature of Bar TH Temperature of Hot Side Thermal Resistance of Thermal Adhesive Thermal Resistance of Thermoelectric Junction ∆T TC Temperature of Cold Side THS Temperature of Heat Sink Thermal Resistance of Heat Sink TA Temperature of Ambient

19. Energy Gain B AreaEclipes= πAB A Area of Dish = 0.303077m² Area of FP = 0.003488m² Energy Gain = Area of Dish / Area of Focal Point Energy Gain = 87

20. Efficiency Strategies 85% Reflectivity Dish Covered with Reflective Tape Absorbs 90% of light Aluminum Collector Plate Painted Black

21. Efficiency Diagram Sunlight to Usable Energy Sun Reflective Tape 85% Efficient 5% Heat to Electricity Efficiency 90% Absorption Efficiency Wasted Heat Step-up Dc/Dc Converter 95% Efficient 12v Lead Acid Total Efficiency = 3.34% 92% Storage Efficiency

22. Power Diagram Sun 8 mins to heat up Collector Concentrator 1000W/m² Heat Sink Thermoelectric Device 303.1W 232W 220W 3V, 6.67A, 20W Dc/Dc Step-up 12V, 1.6A, 19W

23. Dc/Dc Step-up Convertor 1.8V to 5.5V

24. User Interface • Displays: • Time of Day • Date • Azimuth Angle • elevation Angle • Pushbuttons: • Up/Down Selection Arrows • Menu Option • Enter Button mm/dd/yyyy hh/mm pm/am Alt Angle: xx.x° Azi Angle: xx.x° Up Down Menu Enter

25. Areas of Responsibility Evan Kyle Mike Solid Modeling / Thermoelectric Device Mounting / Elevation Tracking Mechanical Energy & Power Calculations/ Thermal Design/ Dc-Dc Step-Up Circuit/ Azimuth Tracking Mechanical / Base Design Solar Tracking Programming/ Real Time Clock Programming/ Angle Calculations/ LCD User Interface Programming and Design

26. Project Management • Work Breakdown Structures for each Subsystem • Weekly Meetings • Weekly Goals

27. Budget

28. Questions?