Heat from a safe high energy density fuel, such as aluminum, is used to generate electrical power. In some applications, the fuel may use seawater as an oxidizer. Additionally, the hybrid power system uses a highly efficient and silent thermoacoustic power converter (TAPC) to convert the thermal energy from the oxidation of aluminum to AC electrical energy. The AC electrical energy is converted to DC energy and stored in a battery. In situations demanding low power, the battery can provide power while the fuel combustion process is suspended.