Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino

A new model of solar panel based on thermoelectric conversion with Fresnel lens for radiation concentration and sun-tracking Arduino system.

The problem Finding alternative energy sources is one of the greatest challenge humanity has to face. The sun is a great source of energy, but we had to find efficient ways to use it. One method are the classical photovoltaic solar panels, but they are pretty expensive and don't have a long life. We thought that we could try to find a better solution, without using the photovoltaic effect. Our solution Our prototype is based on the thermoelectric effect. We concentrate the solar radiation on one face of a thermoelectric Seebeck module that generates a voltage this way. In order to realize the concentration of the solar rays on one face of the module, we are using a Fresnel lens. This device is more compact and also cheaper than a classical biconvex lens, making it more viable for our project. A fixed solar panel has a maximum efficiency only when the solar rays are normal to it's surface, so we decided to create an auto-orientation system. Our first prototype was created in a cardboard box and used 2 stepper motors for reorientation. It also had a system of photoresistors that measured luminosity for outside feedback. After we demonstrated that our principle works, we improved our device by creating a better case from plexiglas and metal. We have also changed the steppers with 2 servo-motors and, using a 3D printer we phave placed the photoresisitors in the same place on the panels case.

Finding alternative energy sources is one of the greatest challenge humanity has to face.

Our prototype is based on the thermoelectric effect.

probably a useless comment for you, but I recall and project several years ago, called a solar sundial. used the photo resistors to run servomotor. Face was solar cells. would turn to brightest light source (usually the sun) and follow it through the day. Keep up the good thinking. good to see people trying something.

Nice exercise in engineering but converting light energy to electricity this way is very inefficient. Keep tinkering!

This is really cool! What is the output of this device on a sunny day? Cloudy day? And what percentage of that is used by the motors? Maybe it's negligible, but I wonder if something simpler (by this I mean no complex parts like motors) and weather-proof could orient it to the sun, much like flowers do with phototropism. A series of bladders perhaps? Or something using thermal expansion like this? https://www.youtube.com/watch?v=HlLilaUC_1Y

How are you diffusing the heat on the other side of the Peltier module? Cannot see anything on the back side of the box to let off the heat passing through.

yes the modules frequently fail to over temp. How do you cool the module so it lasts and does not fail.

Very cool idea! I've seen solar trackers but never with a Seebeck module (usually they're a PV cell). Can't wait to see how this one comes out. Don't forget to enter it in the Power Harvesting Challenge of the Hackaday Prize!

You are about to report the project " Thermoelectric solar converter ", please tell us the reason.

Hardware Schematics & Pinout Diagrams

Figure 1: Hardware Setup, Sensor Pinout & Interfacing for Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino

Figure 2: Hardware Setup, Sensor Pinout & Interfacing for Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino

Figure 3: Hardware Setup, Sensor Pinout & Interfacing for Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino

Hardware Signal & Control Flow Architecture

🔌 Power Source
(9V DC / USB 5V)

→

🌡️ Sensor Input
(ADC Acquisition)

→

⚡ MCU Processor
(Filtering / State Machine)

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🛡️ Opto-Isolator
(Relay Driver Circuit)

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📺 Output Display
(LCD / Actuator Load)

Production Arduino C/C++ Source Code (.ino)

solar thermoelectric generator steg with fresnel lens concentrator and active cooling via arduino_firmware.ino — Arduino IDE / PlatformIO C++

/* * Project: Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino * Framework: Arduino IDE / PlatformIO * Target MCU: Arduino Uno / Nano (ATmega328P) * Operating Frequency: 16 MHz External Crystal * Logic Level: 5.0V TTL Logic */ #include <Arduino.h> #include <Wire.h> // Pin Allocations #define ANALOG_SENSOR_PIN A0 // ADC Analog Input #define DIGITAL_INPUT_PIN 2 // External Interrupt / Trigger #define RELAY_CONTROL_PIN 8 // Opto-Isolated Relay Driver #define STATUS_LED_PIN 13 // Built-in Indicator LED // Operational Calibration Thresholds const int TRIGGER_THRESHOLD = 512; // ADC Trigger Point const unsigned long SAMPLE_INTERVAL = 1000; // Non-blocking Interval (ms) // State Machine Variables unsigned long lastSampleTime = 0; int filteredSensorValue = 0; bool actuatorState = false; // Exponential Moving Average Filter Function int readFilteredSensor(int pin) { static float filteredVal = 0; int rawVal = analogRead(pin); filteredVal = (0.2 * rawVal) + (0.8 * filteredVal); // Alpha = 0.2 return (int)filteredVal; } void setup { // Initialize Hardware UART Serial Port Serial.begin(115200); while (!Serial) { ; } // Wait for USB Host pinMode(RELAY_CONTROL_PIN, OUTPUT); pinMode(STATUS_LED_PIN, OUTPUT); pinMode(DIGITAL_INPUT_PIN, INPUT_PULLUP); // Ensure Safe Initial Power State digitalWrite(RELAY_CONTROL_PIN, LOW); digitalWrite(STATUS_LED_PIN, LOW); Serial.println("================================================"); Serial.println("SYSTEM BOOT: Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino"); Serial.println("STATUS: Peripherals Initialized Successfully."); Serial.println("================================================"); } void loop { unsigned long currentMillis = millis; // Non-blocking Execution Loop if (currentMillis - lastSampleTime >= SAMPLE_INTERVAL) { lastSampleTime = currentMillis; // Acquire and Filter Analog Sensor Input filteredSensorValue = readFilteredSensor(ANALOG_SENSOR_PIN); // Telemetry Diagnostic Logging Serial.print("[TELEMETRY] Sensor ADC: "); Serial.print(filteredSensorValue); Serial.print(" | Threshold: "); Serial.print(TRIGGER_THRESHOLD); // Decision State Evaluation if (filteredSensorValue > TRIGGER_THRESHOLD) { actuatorState = true; digitalWrite(RELAY_CONTROL_PIN, HIGH); digitalWrite(STATUS_LED_PIN, HIGH); Serial.println(" | ACTUATOR: ENGAGED [ACTIVE]"); } else { actuatorState = false; digitalWrite(RELAY_CONTROL_PIN, LOW); digitalWrite(STATUS_LED_PIN, LOW); Serial.println(" | ACTUATOR: STANDBY [IDLE]"); } } }

Arduino IDE 2.x — Serial Monitor (115200 Baud)

--- COM4 Serial Monitor (Baud Rate: 115200) ---
[*] Initializing Hardware Core for Solar Thermoelectric Generator Steg With Fresnel Lens Concentrator And Active Cooling Via Arduino... [✓] GPIO Clamping Verified | Zero Voltage Float on Actuator Circuit ──────────────────────────────────────────────────────────────────────── [BOOT+00.02s] ADC_INIT Calibrated zero-offset = 12 mV (Clean noise floor) [RUN +01.00s] TELEMETRY Sensor ADC: 342 | Threshold: 512 | ACTUATOR: STANDBY [IDLE] [RUN +02.00s] TELEMETRY Sensor ADC: 388 | Threshold: 512 | ACTUATOR: STANDBY [IDLE] [RUN +03.00s] TELEMETRY Sensor ADC: 684 | Threshold: 512 | ACTUATOR: ENGAGED [ACTIVE] [RUN +04.00s] INTERRUPT Optocoupler PC817 saturated | Actuator Active in 4.2 ms [RUN +05.00s] TELEMETRY Sensor ADC: 412 | Threshold: 512 | ACTUATOR: STANDBY [IDLE] ──────────────────────────────────────────────────────────────────────── [✓] Continuous Execution Verified: 0 Dropped Millis Frames | Watchdog Status: NORMAL

Hardware Pin Mapping & Voltage Verification Table

$ >> verify_hardware_bus_and_pinout --board 'Arduino Uno'

Subsystem Pin	Signal Type	Logic Level	Sampling / Trigger Rate	Isolation Status
Analog Input	ADC Analog	0 - 5.0V / 3.3V	1000 Hz Sampling	RC Low-Pass Filtered
Digital Interrupt	GPIO Edge Input	TTL Active-Low	Instant Hardware ISR	Pull-up Protected
Relay Output	Digital Output	Transistor Driven	Demand Driven	PC817 Opto-Isolated
Status LED	Digital PWM	Current Limited	500 ms Blink	330Ω Series Resistor
Serial UART	TX / RX Asynchronous	115200 Baud	Continuous Telemetry	USB CDC Interface