Peltier Solar Concentrator By: Michael Forrest Kyle Fifield Evan White

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.

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

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.

Solar Rays Solar Concentrator Sun Thermoelectric Device Collector Plate Azimuth Rotation Horizontal Tilt Dc/Dc Step-up Microcontroller Motor Controller System Diagram

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 (Altitude)

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

Solar Tracking Positioning Equations Altitude Angle = Azimuth Angle = Inputs Date and Time Longitude and Latitude

Microcontroller Code

Solar Rays Solar Concentrator Sun Thermoelectric Device Collector Plate Azimuth Rotation Horizontal Tilt Microcontroller Motor Controller System Diagram

Mechanical Azimuth Tracking

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

Tracking Code

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.

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

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.

Load and Thermal Expansion Calculations Thermoelectric Device Dimensions Load Required: 200 psi* Force Calculation Thermal Expansion Calculation *Information Given from Specification Sheets

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.

Thermal Resistance Diagram T Bar THTH TCTC T HS TATA ∆T Thermal Resistance of Thermal Adhesive Thermal Resistance of Thermoelectric Junction Thermal Resistance of Heat Sink Temperature of Bar Temperature of Hot Side Temperature of Cold Side Temperature of Heat Sink Temperature of Ambient

Energy Gain B A Area Eclipes = πAB Area of Dish = m² Area of FP = m² Energy Gain = Area of Dish / Area of Focal Point Energy Gain = 87

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

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

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

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

User Interface Displays: Time of Day Date Azimuth Angle Altitude Angle Pushbuttons: Up/Down Selection Arrows Menu Option Enter Button

Areas of Responsibility Evan Kyle Mike Solid Modeling / Thermoelectric Device Mounting / Altitude 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

Project Management

Budget ItemPart NumberStoreLength/Package QuanityOrder QuanityPrice Cold Draw 1" x 1.5" x 12"8910K838McMaster Carr12"1$24.28 Steel Hex Head Cap Screw 3/4"-10 Thread 3 - 1/2" Length91247A849McMaster Carr51$10.45 Hex Nut 3/4"-10 Thread 1-1/4"W, 27/64"H91015A036McMaster Carr51$5.17 Plain Steel Type A SAE Flat Washer 3/4" Screw Size91083A036McMaster Carr211$3.00 Steel Flange-Mounted Ball Bearings 7208K51McMaster Carr11$23.34 Setscrew Shaft Collars 3/8" Bore9414T8McMaster Carr12$0.72 Black-Oxide Coated Steel Shaft 3/8" OD1886K12McMaster Carr18"1$11.40 Steel Timing Belt Pulley Pitch Diameter 0.637", 0.2 Pitch6495K711McMaster Carr11$10.54 Steel Timing Belt Pulley Pitch Diameter 3.80", 0.2 Pitch6495K732McMaster Carr11$38.85 Timing Belt 0.2 Pitch, 27.0" Outer Circle1679K143McMaster Carr11$9.82 Compact DC Gearmotor 12 VDC, 0.6 rpm6409K11McMaster Carr11$44.96 Setscrew Shaft Collars 3/16" Bore9414T5McMaster Carr11$0.62 Aluminum Metric T-Slotted Mounting Bracket, 40mm5537T244McMaster Carr12$13.46 Set-Screw Shaft Coupling 5/16" Bore2424K12McMaster Carr11$7.63 Nylon Flat Belt Idler Pulley 3/8" Bore6235K64McMaster Carr11$ /16" Drive Shaft1327K72McMaster Carr6"1$6.50 TOTAL$237.40

Questions?