TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred System: The photovoltaic system comprises a holding and limiting structure (11) to keep a carpet of aquatic plants (12), this holding and limiting structure (11) is movably connected to the strengthening structure (5), where the holding and limiting structure (11) includes: one or more limiting beams (13) arranged at a distance from the floating structure (3) so as to form a limiting line of the system (1), a series of connection beams (14) with an external end (15) connected to the limiting beam (13) and an internal end (16) connected to the strengthening structure (5) in a movable manner whose height can be regulated so as to be able to adapt the height of the limiting line to the floating line of the photovoltaic system (1), a safety and holding net (19) for the aquatic plants (12) in the space between the limiting line and the floating structure (3) and connected to these limiting beams (13) and the strengthening beams (6). The floating blocks (3) include: hollow bodies of a basically parallelepiped shape with a lower side (20), an upper side (21) and four lateral sides (22) which form four lateral corners (23), a filling opening (24) created in one of the lateral sides (22) to regulate the upward thrust of the floating block (3), connection interfaces (25) arranged in the proximity of these lateral corners (23) and including flanges (26) with through openings (27) that can be vertically overlaid and connected by inserting a connecting pin (28), where these floating blocks (3) are made of synthetic material. The strengthening beams (6) include open cross-section metal profiles with at least two connecting fins (29) coming from this metal profile and limiting openings (30) vertically overlying the respective through openings (27) of the connection interfaces (25) of at least two floating blocks (3). Moreover, the strengthening beams (6) include one or more portions (32, 34) for connecting auxiliary structures (31, 19, 41) selected from: holding and limiting structure, photovoltaic panel support structure, railings, landing stages, and cableways. The supporting frame (9) for the photovoltaic panels (7) rests on two opposing strengthening beams (6) and resting on at least one of these two opposing strengthening beams (6) is performed by interposing an elastic spring (35) between the supporting frame (9) and the strengthening beam (6). 9. Photovoltaic system (1) according to the previous claim, in which this supporting frame (9) includes two long opposing sides and two short opposing sides and two annular seats are formed at each of the opposing short sides (37, 37') basically inserted vertically on respecting connection column bolts (38) fixed to the strengthening beams (6) on which this supporting frame rests (9), and in which a positioning plate (39) is connected to the free end of the connecting column bolt (38) so as to prevent the supporting frame (9) from coming off the connecting column bolt (38), in which: between a first annular seat (37) of each short side and the corresponding strengthening beam (6) there is a helical spring (35) positioned on the connecting column bolt (38) so that the helical spring (35) forms a spacer between the strengthening beam (6) and the supporting frame (9) and elastically prevents the supporting frame (9) from approaching the strengthening beam (6), and between a second annular seat (3V ) of each short side and the positioning plate (39) there is a second helical spring (40) inserted on the connecting column bolt (38) so that the supporting frame (9) rests rigidly against the strengthening beam (6) and the second helical spring (40) elastically prevents the supporting frame (9) from moving away from the strengthening beam (6), and in which the arrangement of the elastic springs (35, 40) provides a slight inclination of the supporting frame table (9) and of the photovoltaic panel (7) connected to it with respect to the table (P) of the floating structure (3). The photovoltaic system (1) comprises a floating landing stage (41) to connect the floating photovoltaic system (1) to the shore, in which this landing stage (41) includes joints (42) which permit a relative movement and rotation between two adjacent floating segments.