The development of hybrid photovoltaic modules that combine high efficiency concentrating photovoltaic (CPV) cells for the conversion of direct sunlight and non-concentrating photovoltaic (FV) cells for the conversion of diffused or global sunlight. Among these modules, the Hybrid Solar Modules with integrated solar tracker (Module with Integrated Tracker , MIT ) stand out which, thanks to the use of the internal tracker, can be installed on biaxial solar trackers that do not require high precision.

In this context, RSE has started the development of an innovative technology, HYB Quantum, with the aim of coupling a new MIT to a low resolution external solar tracker, called “Quantum.” The quantum tracker, on which the MIT is installed, is designed to make discrete movements along the azimuth axis, in 10° increments, and only two movements along the elevation axis. This movement allows the angle of incidence of the sun’s rays to be maintained within a limited range of values, thus reducing “cosine” losses.

The coupling of the two solar trackers maximizes energy production, reducing costs and ensuring greater reliability thanks to a simplified control system based on shape memory actuators, known for their ability to operate even in humid and corrosive environments for long periods

To achieve these goals, a complete functional unit UFC of MIT was designed that integrates three types of photovoltaic cells (one CPV cell array and two FV cell arrays) and with an internal tracker based on Shape Memory Alloy SMA springs. The internal tracking system is characterized by a simplified and low-cost control logic that uses a new solar alignment sensor developed with LED matrices. To follow the movement of the focal point as the angle of incidence of the sun’s rays varies, the internal movement is of the 2.5D type: the plane of the CPV cells moves parallel to the plane of the optics, fixed on the upper part of the UFC, on a circular trajectory in the movements along the y axis and constant with respect to the movements along the x axis.

To verify the reliability of the SMA springs, aging tests were performed which indicated a moderate degradation of the force exerted by the SMA springs, which is not expected to impact the operation of the solar tracker during its expected operational life of 20 years.

Finally, a feasibility study was carried out to verify the possibility of moving the Quantum solar tracker also with SMA springs. A new solar pointing sensor with a 360° field of view has been designed for this tracker which allows for a simplification of the control system.

The Report is available on the Italian site