Generally, vehicles driven by fuels, such as gasoline, diesel, and aviation oil, are equipped with water tanks. These vehicles include vans, cars, heavy locomotives, fire engines, ambulances, aircraft, and boats. The cooling water in these water tanks absorbs the heat generated by engines and then gradually heats up. Nowadays, the heated cooling water is usually channeled into a radiator and returned to the water tank until the heat is dissipated. This has caused the problem of energy waste in the cold–hot conversion process, which increases the environmental impact of the vechicles. Therefore, in this research, a thermal power generation device is designed with a simple structure, composed of a Pt100 thermocouple thermometer and a thermistor with an LM358 operational amplifier as two different sensing devices. The designed device is expected to increase the power generation capacity without using additional energy for cooling thermoelectric power generation chips. Therefore, it is of great importance to cool the surface of the chips. Thermoelectric power generation chips are installed at the four corners of the front and rear of a water tank. The thermal energy generated by the water tank is used to generate electric energy, which achieves the purpose of energy recycling. The designed device is cost-effective and can achieve the purpose of reducing environmental impact and energy conservation. This research can be used as a reference for vocational education from the aspects of technology, management, design, technicalization, and research and development.