Combined cycle power plant with gas and steam turbo groups

Method and plant in which a pair of pre-existing steam turbo groups, a first of which composed of a first steam turbine (2) and a first electric generator (6) connected on a first common axis (4) and a second of which composed of a second steam turbine (3) and a second electric generator (7) connected on a second common axis (5), are reciprocally coupled in a 'cross-compound' type configuration and with a gas turbine (20) to form a combined cycle plant for generating energy; wherein a high pressure section and a medium pressure section of the second steam turbine (3) are hydraulically isolated and possibly removed and a medium pressure section (12) of the first steam turbine (2), hydraulically connected in series downstream of a high pressure section (10), is hydraulically connected in cascade, in parallel, with a low pressure section (14) of the first steam turbine (2), by means of a first pipeline (42) and with a low pressure section (15) of the second steam turbine (3), by means of a second pipeline (44) arranged in offtake to the first; consequently the second electric generator (7) is activated exclusively by the low pressure section (15) of the second steam turbine.