The invention comprises: a structure (3) supporting at least one refraction-based concentration element (1) and at least one collector (2) positioned parallel to one another; and first actuation means operatively connected so as to pivot the structure in relation to a base (4) about a first axis (E1) parallel to the concentration element and to the collector, in order to track a relative movement of the sun. The concentration element is fixed in a stationary position on the structure and the collector is supported in said structure at least two rocker arms (5) positioned parallel to one another and connected at the ends thereof to form an articulated quadrilateral mechanism. In addition, second actuation means are operatively connected so as to pivot the arms in relation to the structure about respective second axes (E2) adjacent to the concentration element and perpendicular to the first axis, so that the collector can at any time be positioned at a maximum concentration point.