A prepaid energy meter system is developed using an ESP32 microcontroller to monitor real-time power consumption of electrical loads using a PZEM module. The system measures voltage, current, power, and energy usage, and processes this data to provide accurate consumption tracking. Based on the measured energy usage, the system continuously deducts units from a prepaid balance. When the balance reaches a low or zero level, the ESP32 automatically sends an alert notification via email to the user. If the balance becomes insufficient, the microcontroller controls a relay-based contactor to disconnect the power supply, preventing further usage. Upon successful recharge through a web-based interface, the system restores the power supply seamlessly. The system also supports data monitoring and user interaction through a secure web platform, with scope for future expansion to multiphase energy measurement and enhanced authentication features. By providing real-time usage insights, automated billing, and remote monitoring, this prepaid energy meter system improves energy efficiency, promotes better cost management, and ensures transparent and reliable power usage control.      

Objectives:

• To design a prepaid energy meter using ESP32.
• To measure real-time voltage, current, and power using PZEM module.
• To calculate and monitor energy consumption continuously.
• To implement prepaid billing system with automatic balance deduction.
• To disconnect power supply when balance is low or zero using relay.
• To provide alerts (Email) for low balance notification.
• To enable online recharge system through web interface.
• To ensure efficient energy usage and cost management.

        Components Used:

• Regulated Power Supply.
• ESP32 Microcontroller.
• PZEM MODULE.
• LCD Display.
• Relay.
• Load(Bulb).

      Software’s Used:

1. Arduino IDE studio compiler for dumping program.
2. Express SCH for Circuit design.

              Regulated power supply:

           

Block Diagram:    

video: