Any form of energy is associated with the vibrations of molecules atoms or electrons. Basically mechanical energy constitutes of kinetic and potential energies. The a body changes its position with respect 2 the surrounding with the help of kinetic energy. Potential energy is linked with the stability of the body. Thermal energy is the process where the heated vapours of water or air helps to turn a turbine. The heated molecules have potential energy which converts into kinetic energy for the turbine as per law of conversion of energy.Hence they are technically same.