System for generating mechanical and/or electrical energy

The system has a combustion chamber (11) for burning fuel with compressed air (16) of the compression section (10) into high-energy hot gas (15a). A turbine (12) expands the hot gas for subsequent recovery of mechanical energy for compressor and generator (13). An expander (30) expands work fluid (36) in the work fluid circuit. A pump (32) conveys work fluid condensed by a capacitor (31). The compressor section of gas turbine system is coupled with closed work fluid circuit through heat exchanger (33).