In January 2015, Soitec announced a strategic refocus on its core electronics business and its willingness to transition away from its solar energy activities, in compliance with its obligations towards all solar stakeholders. Please find more information in the "News" section of this website.

Soitec’s high-performance CPV technology

Soitec’s CPV technology uses high-quality components optimized for longevity and durability, delivering high performance over the entire system lifetime. Our R&D department works continuously to further optimize the product design, manufacturing quality, and output for increased efficiency, lower costs, and guaranteed product quality and performance.

Multi-junction solar cells

Soitec CPV technology uses optimized III-V-based multi-junction solar cells in which different sub-cells are stacked on top of one another. Each sub-cell is designed to convert a certain range of the solar spectrum: short wave radiation, medium wave radiation and infrared. Multi-junction solar cells are used in space applications for over 20 years.

The energy yield and the efficiency increase potential of these high-efficiency cells are enormous. In 2014 – a new world record for the direct conversion of sunlight into electricity has been established by Soitec in cooperation with CEA-Leti France and the Fraunhofer Institute for Solar Energy Systems ISE Germany. The new record cell converts 46% of the solar light into electrical energy. This new record confirms that Soitec made the right technology choice when deciding to develop this four-junction solar cell. It clearly indicates that Soitec can demonstrate 50% efficiency in the near future. To produce this new generation of solar cells, Soitec has installed a line in France using its proprietary bonding and layer-transfer technologies. Striving for 50% efficiency will further increase CPV technology competitiveness.

In comparison to conventional solar cells, multi-junction solar cells are more efficient but also more expensive to manufacture. By using concentrating optics to focus the sunlight on these multi-junction solar cells, it is possible to minimize the amount of semiconductor material needed down to a small fraction, using cells of only a few square millimeters. This principle enables the manufacturing of CPV modules which are both highly efficient and inexpensive.

Soitec’s expertise in engineered substrates provides the right environment for the development of our own solar cell for use in our CPV module technology. With this program, Soitec aims to bring record efficiency solar cells into mass-production.

This new cell will use proprietary technology from Soitec (Smart Cut™ and Smart Stacking™), to transfer and bond thin layers of high quality crystalline semiconductor materials. Our two partners are playing key roles in this project: CEA-Leti contributes leading-edge research applicable to Smart Cut technology; and the Fraunhofer ISE leverages its expertise in III-V multi-junction solar cells. Together, we will create multi-junction cells made of high-quality III-V compounds materials that deliver significantly higher efficiency than conventional multi-junction cells grown by epitaxy.

CPV modules

module.jpgSoitec CPV modules are made up of a lens plate (Fresnel lens) and a receiver plate on which the high-performance solar cells are mounted. The Fresnel lenses focus sunlight concentrated by a factor of 500 on the solar cells beneath.

The cells are very precisely mounted on the receiver plate, enabling the focused sunbeam to hit the tiny solar cells perfectly.

Soitec manufacturing facilities use elements from the circuit board industry and the insulating glass technology which are both cost-effective and have been proven reliable over many years. Precision and quality in the module manufacturing lead to an extremely high module efficiency of 32,8%.

Soitec's CPV modules are certified according to IEC and UL standards and won listing with the California Energy Commission (CEC)

The IEC 62108 and the UL62108 standard specify the requirements for the design qualification and type approval of CPV Modules suitable for long-term operation under harsh outdoor conditions. According to the testing standards for conventional photovoltaic modules, the IEC 62108 norm simulates environmental conditions for CPV modules to verify the performance reliability and aging resistance. This includes extensive climatic chamber testing and testing of hail impact, mechanical load, hot spot endurance, insulation as well as outdoor exposure. Moreover, the CX-M500 module complies to the CPV safety standards IEC 62688 Draft und UL SU 8703.

The CEC listing is vital to doing business in California and a key step in financing commercial projects with customer companies and state energy utilities.

All Soitec CPV module generations have been certified according to IEC 62108 since 2009.

Tracking systems

Soitec’s CPV technology requires the use of a dual-axis tracking system to ensure that concentrated sunlight remains focused on the solar cells with a high degree of precision throughout the day, delivering constant power output.

A proprietary application and algorithm position the tracker. Astronomical positioning is used and DC power output is monitored to calculate the next optimum position for maximum power generation.

Our tracking systems have to meet the following reliability requirements:

  • Robust enough to enable the module to produce energy even at high wind speeds
  • Accurate tracking of the sun for optimum electricity generation
  • Simple gear and motor maintenance

Concentrix technology is compatible with tracking systems of different types and sizes to meet customer needs.