The invention is directed by an ORC (Organic Rankine Cycle) system at least partially co-generative for a production of electric energy and the heating of a user fluid. The system comprises at least two regenerative exchangers (20-24) positioned in series on the route of the work fluid between the exit of an electric expander-generator group (16) and the entrance of a condenser (18) of the ORC system, and at least a heat exchanger-user (26) connected by means of an offtake line (25) to at least one of said regenerative exchangers (20 - 24) to receive from them at least a part of the capacity of work fluid and crossed by the user fluid to be heated by means of a thermal exchange with said capacity of work fluid. The part of the capacity of the work fluid on exiting from the user exchanger is returned to the same regenerative exchanger.
