An apparatus for the accumulation and transfer of thermal energy, comprising: ▪ at least one thermal energy charging device , having a fluid bed of solid particles received within a casing and acting as heat accumulation means by being exposed to a thermal energy source; ▪ heat exchange means , configured for an exchange of thermal energy between a heated vector mass of said bed particles and an operative fluid, said heat exchange means being configured for counter-current exchange; ▪ transport means , configured for feeding said vector mass of said bed particles from said energy charging device to said heat exchange means and for returning at least a part of said vector mass, downstream said heat exchange means , to said energy charging device , characterised in that the apparatus further comprises parameter detecting means arranged at one or more selected locations of the apparatus and comprising temperature sensors; and ▪ a control unit , configured to control the flow of said vector mass within the apparatus on the basis of parameter values pre-programmed and of parameter values detected by said parameter detecting means , wherein said control unit is configured to adjust the particle mass flow rates entering and leaving said energy charging device according to the available power input so as to keep a detected value of the fluid bed temperature within a desired range, and wherein said control unit is configured to control operation of said heat exchange means by adjusting the solid particles mass flow rate crossing the heat exchange means according to the operative fluid mass flow rate and temperature desired for use. ▪ at least one thermal energy charging device , having a fluid bed of solid particles received within a casing and acting as heat accumulation means by being exposed to a thermal energy source; ▪ heat exchange means , configured for an exchange of thermal energy between a heated vector mass of said bed particles and an operative fluid, said heat exchange means being configured for counter-current exchange; ▪ transport means , configured for feeding said vector mass of said bed particles from said energy charging device to said heat exchange means and for returning at least a part of said vector mass, downstream said heat exchange means , to said energy charging device , characterised in that the apparatus further comprises parameter detecting means arranged at one or more selected locations of the apparatus and comprising temperature sensors; and ▪ a control unit , configured to control the flow of said vector mass within the apparatus on the basis of parameter values pre-programmed and of parameter values detected by said parameter detecting means , wherein said control unit is configured to adjust the particle mass flow rates entering and leaving said energy charging device according to the available power input so as to keep a detected value of the fluid bed temperature within a desired range, and wherein said control unit is configured to control operation of said heat exchange means by adjusting the solid particles mass flow rate crossing the heat exchange means according to the operative fluid mass flow rate and temperature desired for use. <EOS>