Cogeneration system (200, 300) comprising: a boiler (201, 301) able to heat water for domestic use; a combustor (201a, 301a) placed into the boiler; a compressor (204, 304); a heat exchanger (202, 302) for the exchange of thermal energy between the combustion fumes generated in the combustor (201a, 301a) and a fluid coming from the compressor (204, 304); a gas turbine (203, 303); a current generator (205, 305) and a current converter (206, 306) able to produce electrical energy; a main fumes/water exchanger (207, 307) able to recover thermal energy.
The cogeneration system (200, 300) comprises also a by-pass valve (210, 310) configured to adjust the flow of fluid entering the gas turbine (203, 303).