Electrical energy is a major necessity in modern life that supports various activities, from lighting to technology operation. However, energy waste and difficulties in monitoring electricity consumption in real-time are still major challenges. This research aims to design and develop an intelligent electrical energy monitoring system based on the Internet of Things (IoT) that is able to observe energy consumption directly and provide early warnings to users. The system uses ESP32 as the main microcontroller, PZEM-004T as the alternating current (AC) sensor, PZEM-017 as the direct current (DC) sensor, and DS18B20 sensor to monitor the temperature of the system. The system provides real-time energy consumption data through LCD displays and web-based platforms, allowing users to access information anytime and anywhere. In addition, the IoT-based notification feature can provide early warnings to users, so users can optimize energy use more efficiently. The test results show that the system is able to read AC, DC and system temperature electrical parameters with an average error of less than 1%, both in voltage, current, power, energy, frequency and system temperature. Website monitoring successfully displays data in real-time with a delay within tolerance limits and an active early warning system (buzzer) when abnormal conditions such as AC and DC voltages exceeding the specified threshold or system temperatures exceeding 60°C. In addition, the system is able to convert energy consumption into estimated electricity bills (PLN) and profits for (PLTS), thus providing cost control and electricity use efficiency to users. The implementation of IoT technology in electricity monitoring is expected to be an innovative solution in reducing energy waste and managing energy more intelligently and sustainably.