Introduction
A Solar Smart City is an advanced concept where solar energy is used as the primary power source to operate smart city infrastructure such as street lights, traffic signals, water systems, surveillance cameras, and environmental monitoring units.
This project combines renewable energy (solar power), IoT, automation, and smart monitoring to create an energy-efficient, eco-friendly, and sustainable urban model.
Objective of the Project
- To utilize solar energy for powering smart city systems
- To reduce dependency on conventional electricity
- To monitor and control city infrastructure using IoT
- To promote green energy and sustainability
Working Principle
The Solar Smart City system operates by converting solar energy into electrical energy using solar panels and storing it in batteries. This stored energy powers multiple smart modules connected across the city.
Step-by-Step Working
- Solar panels generate electricity from sunlight
- Solar charge controller regulates charging of the battery
- Battery stores energy for day and night usage
- ESP32 / Arduino controls smart modules
- Sensors collect real-time data (light, motion, pollution, water level)
- IoT platform displays city data and controls automation
Major Smart City Modules
- Solar-powered street lighting
- Smart traffic signals
- Smart waste management
- Water level monitoring
- Air quality monitoring
- Smart parking system
Components Required
- Solar Panel (6V / 12V)
- Solar Charge Controller
- Rechargeable Battery (Li-ion / Lead Acid)
- ESP32 / Arduino Uno
- LDR Sensor (for street lights)
- PIR Sensor (motion detection)
- Ultrasonic Sensor (parking / waste level)
- MQ135 (air quality monitoring)
- Relay Module
- LEDs (street lights, signals)
- IoT Platform (Blynk / ThingSpeak / Firebase)
Block Diagram (Solar Smart City)
Solar Panel
↓
Charge Controller
↓
Battery
↓
ESP32 / Arduino
↓
--------------------------------
| LDR | PIR | MQ135 | Ultrasonic |
--------------------------------
↓
Relays / Loads (Lights, Signals)
↓
IoT Cloud Dashboard
Circuit Explanation (Solar Street Light Example)
Solar Panel → Charge Controller → Battery → ESP32
LDR → ESP32 GPIO
Relay → ESP32 GPIO → Street Light
- LDR detects light intensity
- ESP32 decides ON/OFF condition
- Relay controls street light
- Power is supplied entirely by solar energy
Arduino Code (Solar Smart Street Light)
#define LDR_PIN 34
#define RELAY_PIN 26
void setup() {
pinMode(RELAY_PIN, OUTPUT);
Serial.begin(9600);
}
void loop() {
int ldrValue = analogRead(LDR_PIN);
Serial.println(ldrValue);
if (ldrValue < 1500) { // Night condition
digitalWrite(RELAY_PIN, HIGH); // Light ON
} else {
digitalWrite(RELAY_PIN, LOW); // Light OFF
}
delay(1000);
}
Code Explanation
- LDR senses sunlight intensity
- ESP32 checks threshold value
- At night, relay turns ON street light
- During daytime, light remains OFF
- Solar battery supplies power continuously
Advantages
- Uses renewable and clean energy
- Reduces electricity bills
- Low maintenance cost
- Environment friendly
- Ideal for smart city development
Applications
- Smart cities and townships
- Smart highways and street lighting
- Eco-friendly urban infrastructure
- Government and municipal projects
Future Enhancements
- Integrate AI-based traffic prediction
- Use solar tracking system for maximum power
- Cloud-based centralized smart city dashboard
- EV charging stations powered by solar energy
Conclusion
The Solar Smart City project demonstrates how renewable energy and smart technology can work together to build sustainable urban environments. It is an excellent model for future cities, reducing pollution and energy consumption while improving efficiency and automation.
