The invention provides a portable electronic system. The portable electronic system includes a semiconductor package. The semiconductor package includes a substrate. A semiconductor die is coupled to the substrate. A thermoelectric device chip is disposed close to the semiconductor die, coupled to the substrate. The thermoelectric device chip is configured to detect a heat energy generated from the semiconductor die and to convert the heat energy into a recycled electrical energy. A power system is coupled to the semiconductor package, configured to store the recycled electrical energy.