The rapid advancement of technology has led to an increasing demand for electrical energy. One of the efforts to meet this demand is the development of micro-capacity power generation systems utilizing heat energy. Heat energy can be harnessed using thermoelectric elements. This study aims to design and develop a portable power generation system that utilizes solar heat as an energy source. The prototype uses six TEC 1-12706 thermoelectric modules to generate electricity designed specifically to recharge devices such as phones, power banks, and flashlights. Solar heat is concentrated on the thermoelectric modules using Fresnel lenses, while heatsinks are employed for cooling. The thermoelectric modules are connected in series to produce sufficient voltage, which is then boosted by a boost converter. The generated electrical energy is stored in a battery to ensure voltage stability despite temperature fluctuations. This device can also operate at night due to the energy stored in the battery. Test results show that the average output voltage without load ranges from 9.49V to 9.56V, with an average temperature of 45.2°C at the thermoelectric modules. In load tests, the device successfully charged a Pixel 5 phone (5000 mAh battery) from 4% to 70% in 95 minutes. These results demonstrate the potential of this system as a reliable and environmentally friendly portable energy solution.

The unwise use of electrical energy in households can lead to energy wastage and pose risks such as short circuits, which may result in fires. This research developed a Node-Red-based protection system using an ESP8266 microcontroller and a PZEM 004-T sensor to detect voltage, current, and power in real-time. The system automatically disconnects the current when overload conditions are detected, especially on extension cables. Testing was conducted on household devices such as laptop chargers, fans, and soldering irons. Results demonstrate that the system can accurately monitor current and power, maintain electrical stability, and cut off electricity when the load exceeds the safe threshold, thus reducing fire risk. This implementation is expected to enhance household electrical safety and serve as a reference for further development in IoT-based protection systems.