Device to control the energy conversion in the mixed thermal and photovoltaic solar concentrators

Solar concentrators that transform solar energy in both electrical energy and heat energy do not control the proportion of electrical energy which is produced compared to that of the heat energy. This proportion is left to chance fluctuations in the brightness of the sun while it may be interesting to focus on the production of energy compared to another. The invention discloses a device which enables this control output. It is composed of an optical solar concentration (1), preferably a Fresnel lens (1), and a target composed for example of a photovoltaic cell (4) and a thermal sensor (5) positioned at least the periphery of the cell (4). The distance (D2) between the Fresnel lens (1) and the cell (4) is variable which also causes a change in the size of the illumination surface (7B) of the concentrated solar radiation (3) on the target. When the size of the illuminated surface (7B) is low, the light intensity is large and centered on the photovoltaic cell (4) which thus produces a maximum electrical energy. When the size (7B) is important light intensity is lower and is also distributed on the surface of the thermal sensor (5) placed on the periphery, resulting in a larger heat energy and a lower production of electrical energy. Automatic control is provided for regulating the light intensity received by the cell (4) even during variations in brightness of the sun.