Option 1: Nuclear energy is a form of stored energy. It is released during nuclear reactions, such as nuclear fission or fusion, where atoms are split or combined to release a huge amount of energy.

Option 2: Potential energy is a form of stored energy. It refers to the energy possessed by an object due to its position or condition. For example, a ball held up in the air has potential energy, which is converted to kinetic energy when it falls.

Option 3: Electrical energy is not a form of stored energy. Electrical energy is the energy generated or consumed by the flow of electric charge through a conductor. It is produced by the movement of electrons in a circuit and is not stored in any particular medium like the other options.

Option 4: Chemical energy is a form of stored energy. It is the energy stored in the bonds of chemical compounds. When chemical reactions occur, this energy is released or absorbed. Common examples of chemical energy sources are batteries and fossil fuels.

In conclusion, option 3 (Electrical energy) is not a form of stored energy, as it is generated and consumed in real-time through the movement of electric charges in a circuit.