The first phase of the round-robin initiative under the IEC TC82 WG7 international standards committee concluded successfully at the Polytechnic University of Madrid. The initiative aimed to validate the new standard procedure proposed by RSE for characterizing CPV/PV modules with integrated solar tracking systems. Researchers from RSE collaborated with those from the Solar Energy Institute of the Polytechnic University of Madrid, using a prototype CPV/PV hybrid photovoltaic module developed by RSE during the 2022–2024 RdS triennium.

The CPV/PV hybrid photovoltaic module consists of three arrays of solar cells designed to capture both direct and diffuse light. During the tests, the CPV component of the module demonstrated a conversion efficiency of approximately 33%, utilizing solar concentration.

This initiative also provided an opportunity to showcase to international partners the potential of RSE’s new photovoltaic technology, which addresses barriers that have hindered the widespread adoption of concentrated photovoltaics (CPV). In addition to converting diffuse solar radiation, the new technology significantly reduces the costs of solar tracking systems by eliminating the need for high-rigidity mechanical structures and reducing the number of components. These simplifications improve system reliability and lower its life-cycle environmental impact.

At the heart of the solar tracking system is an innovative control system based on shape memory alloy (SMA) actuators and LED arrays. A key innovation of RSE’s technology is that the integrated solar tracker allows the module to operate at solar concentration levels exceeding 300 suns, with angular misalignments of up to 17° relative to the direction of solar rays. This results in several advantages:

The use of high-efficiency multi-junction cells, with reduced costs due to concentration factors.
Consistently high performance, regardless of thermal and mechanical stresses from environmental factors.
Elimination of the need for precise module installation.

Figure 2: Photo (a) shows the module designed by RSE specifically for the “proof of concept” of the solar tracking system combined with the optical system, used in the round Robin. The optical system consists of four hexagonal lenses that concentrate light onto the CPV cells inside the module. In the future, the surface of the lenses will cover most of the front face of the module, eliminating the currently painted cream-colored area; in addition, the PV cells mounted around the lenses will have a smaller surface area, and some of them will provide the necessary power to drive the solar tracker, making an external power supply unnecessary. Photo (b) illustrates light focused on a multi-junction (MJ) cell through one of the hexagonal lenses. The alignment between the CPV cell and the optics is ensured by the internal solar tracking system, driven by shape memory springs. The system automatically adjusts the position of the plane on which the cell is installed to keep the light spot at its center as the sun’s angle of incidence changes.

Future Prospects:

RSE is actively conducting research and development to further optimize the CPV/PV hybrid technology and demonstrate its potential on a larger scale. Simulations suggest up to a 50% increase in energy production compared to traditional PV systems with single-axis trackers, given the same land area.

RSE’s technology opens new horizons for the photovoltaic sector, offering a more efficient, reliable, cost-effective, and sustainable solution for clean solar energy production.

To complete the development activities and accelerate the final commercialization phase, RSE aims to collaborate with experienced companies in the photovoltaic sector. The goal is to finalize the module design for applications ranging from utility-scale installations to agrivoltaics, including EV charging stations and building-integrated solutions. This technology is particularly suitable for space-constrained contexts, where high efficiency is crucial.