"Thermal Energy" is the portion of the thermodynamic or internal energy of a system that is responsible for the temperature of the system. From a macroscopic thermodynamic description, the thermal energy of a system is given by its constant volume specific heat capacity C(T), a temperature coefficient also called thermal capacity, at any given absolute temperature (T): $U_{thermal} = C(T) \cdot T$.
Applicable units are those of quantitykind:ThermalEnergy
Thermal Energy