Modular photovoltaic system

A modular product for producing photovoltaic installations, comprising a plurality of flat photovoltaic modules, each photovoltaic module comprising two parallel and vertical posts connected to one another by a first crossbeam and by a second crossbeam which are arranged orthogonal to the posts, one, two or more photovoltaic panels arranged vertically in a space delimited by the posts and the crossbeams, wherein the first crossbeam is positioned at the top of the photovoltaic module above the photovoltaic panels and the second crossbeam is positioned at the bottom of the module, below the photovoltaic panels, comprising a horizontal cable-guide device fixed to the second crossbeam below said second crossbeam, comprising an electrical circuit between the posts allowing electrical connection of an adjacent photovoltaic module, wherein the photovoltaic modules have an empty space between two photovoltaic panels and wherein the space of a first photovoltaic module is aligned with a vertical axis equidistant from the posts and is able to accommodate an identical or compatible second photovoltaic module forming a right angle with the first photovoltaic module.