Solar Power Monitoring System

System Overview

Monitor your solar installation to maximize efficiency and detect issues early. Track production, consumption, and battery health in real-time.

Sensors Required

• INA219: Voltage/current (0-26V, 0-3.2A)
• INA3221: 3-channel power monitor
• Voltage Divider: For higher voltages
• Current Transformer: AC current sensing
• DS18B20: Panel temperature

Hardware Setup

ESP32 → INA219 (Solar Input)
VCC → 3.3V, GND → GND
SDA → GPIO21, SCL → GPIO22

ESP32 → INA219 (Battery)
VCC → 3.3V, GND → GND
SDA → GPIO21, SCL → GPIO22 (shared I2C)

ESP32 → Voltage Divider (Panel)
Panel+ → 10k resistor → GPIO35 → 10k resistor → GND

ESP32 Firmware

#include 
#include 
#include 
#include 

Adafruit_INA219 solar_ina;
Adafruit_INA219 battery_ina;

void setup() {
  solar_ina.begin();
  battery_ina.begin();
  
  WiFi.begin(ssid, password);
  client.setServer(mqtt_server, 1883);
}

void loop() {
  // Solar production
  float solar_voltage = solar_ina.getBusVoltage_V();
  float solar_current = solar_ina.getCurrent_mA();
  float solar_power = solar_voltage * solar_current / 1000;
  
  // Battery status
  float battery_voltage = battery_ina.getBusVoltage_V();
  float battery_current = battery_ina.getCurrent_mA();
  int battery_soc = map(battery_voltage * 10, 110, 127, 0, 100);
  
  // Publish
  publishSolarData(solar_voltage, solar_current, solar_power, 
                   battery_voltage, battery_current, battery_soc);
  
  delay(5000);
}

Dashboard Setup

Key metrics to display:

• Real-time power flow diagram
• Daily energy production graph
• Battery SOC gauge
• Self-consumption ratio
• Savings calculation