The electrol coil on a stove has both potential and kinetic energy. While the stove is off, the coils are cool to the touch. When the stove is turned on, the coils start to heat up. The potential energy is in the battery or power station because that is where the electricity is stored. The kinetic energy is heat that is given off when stove gets turned on. During any process, the net electric charge of an isolated system remains constant.