System for converting potential and/or kinetic energy of a body weighing upon or travelling over a support and/or transit plane into energy comprising - a fixed framework with which at least one footboard is associated in a mobile manner, said footboard defining said support or transit plane and being mobile, by the action of said body, between an initial position and an end position, - a magnetic interaction device that comprises at least two elements (42, 43) that are associated with one another in a mobile manner relative to one another, the mobile one of which is associated with at least one magnet, means for counteracting the relative motion of said two elements (42, 43) characterised in that it comprises at least one activation magnet for setting said mobile element in motion with respect to the other fixed element, wherein said magnetic interaction device takes up a first configuration, in which said activation magnet is outside of the field of interaction with the magnet of said mobile element, and a second configuration, in which said activation magnet is inside the field of interaction with the magnet of said mobile element, - and means for transmitting the motion of said footboard between said initial position and end position to one from said activation magnet and the combination of said two elements (42, 43) for the passage of said magnetic interaction device from said first configuration to said second configuration, or vice-versa, setting said mobile element in motion with respect to the fixed element without any contact, - wherein the relative motion of said two elements (42, 43) makes energy available that can be used in the form of variation of a magnetic flux or of pressure of a fluid. - a fixed framework with which at least one footboard is associated in a mobile manner, said footboard defining said support or transit plane and being mobile, by the action of said body, between an initial position and an end position, - a magnetic interaction device that comprises at least two elements (42, 43) that are associated with one another in a mobile manner relative to one another, the mobile one of which is associated with at least one magnet, means for counteracting the relative motion of said two elements (42, 43) characterised in that it comprises at least one activation magnet for setting said mobile element in motion with respect to the other fixed element, wherein said magnetic interaction device takes up a first configuration, in which said activation magnet is outside of the field of interaction with the magnet of said mobile element, and a second configuration, in which said activation magnet is inside the field of interaction with the magnet of said mobile element, - and means for transmitting the motion of said footboard between said initial position and end position to one from said activation magnet and the combination of said two elements (42, 43) for the passage of said magnetic interaction device from said first configuration to said second configuration, or vice-versa, setting said mobile element in motion with respect to the fixed element without any contact, - wherein the relative motion of said two elements (42, 43) makes energy available that can be used in the form of variation of a magnetic flux or of pressure of a fluid.