An assembly for generating electrical and thermal energy has a structure that supports a cogeneration device provided with a combustion engine supplied with fuel, an electric generator driven by the combustion engine, and at least one heat exchanger to heat a fluid for a thermal appliance using the heat produced by the combustion engine; the assembly also has a plurality of storage batteries, which guarantee the continuity of the flow of electrical energy during start-up of the electric generator and during load transients and are housed in a base of the structure.