Concentrix™ technology : Q&A
What are the differences between Soitec’s Concentrix technology and conventional PV technology?
Concentrix technology is based on Concentrator Photovoltaic system (CPV), whereby sunlight is focused onto highly-efficient solar cells using Fresnel lenses. CPV offers efficiencies twice those of standard silicon PV technologies.
What are the advantages of Concentrix technology compared to other solar technologies?
In the sunbelt, CPV is the most cost-effective way to generate solar electricity. In addition to cost, the technology offers a number of other advantages:
- CPV produces energy when it is needed most
- CPV has the smallest environmental footprint
- CPV creates local jobs and local value
To have a useful comparison, it is important to look not at system costs, but rather at electrical production costs, which are calculated by depreciating the initial investment costs, adding operating and maintenance costs, and factoring in annual energy yield. There is a much stronger relationship between cost and plant location (i.e., the available solar radiation) than for conventional PV systems. In sunny locations, customers can count on a cost advantage of about 10% to 15%.
Who developed Concentrix technology?
The CPV technology registered under Concentrix technology was developed by Concentrix Solar GmbH, a spin-off of the Fraunhofer Institute for Solar Energy Systems. Soitec acquired Concentrix Solar in 2009. The manufacturing technology was developed through ten years of research at the Fraunhofer Institute. Since the 1970s, various research groups have been working on the science that underpins concentrator photovoltaic technology. Scientists at the Ioffe Institute, the University of Madrid, and NREL all made pioneering contributions that laid the important groundwork for this new technology. Since the mid 1980s, scientists at the Fraunhofer Institute for Solar Energy Systems had been working on concentrator photovoltaic cells and systems. In 2002, the institute shifted the focus of its CPV research to production technologies and transfer to industry.
What is the advantage of using glass for the Concentrix modules’ front and back plates?
Glass is very durable and scratch resistant, which is very important for use in desert-like environments. Glass is 40 times more scratch-resistant than acrylics. Glass is also a low-cost material with a low thermal expansion coefficient.
What efficiencies does Concentrix technology offer?
The Concentrix system achieves nominal AC system efficiency of 25% in normal operating conditions in the field. The modules achieve efficiencies of 30%, and the solar cells used achieve efficiencies of 38%, respectively. Concentrix technology is twice as efficient as conventional silicon technology.
What is the energy yield of a Soitec CPV power plant?
The amount of electricity produced is firstly dependent on the location. Concentrix technology is especially suitable for use in regions having a large fraction of direct solar irradiation and guarantee large energy outputs even at high ambient temperatures. For locations with an annual direct normal irradiance (DNI) of 2500 kWh/m²yr, the electricity yield per installed AC nominal power rated at 850 W/m² DNI is 2600 kWh/kWnom. With the DC module peak power rating equivalent to conventional PV at 1000 W/m², the specific energy yield will be 1900 kWh/kWp.
What maintenance is required for a Soitec CPV power plant?
Maintenance on CPV systems is similar to that of conventional photovoltaic systems. The modules must be cleaned periodically, and the trackers require basic gear and motor maintenance.
Where are the target markets for Soitec’s CPV power plants?
The efficiency of the technology is dependent on high direct solar radiation. Therefore, the technology is best suited to very sunny countries like Spain, southern Italy, the southwestern United States, South Africa, and Australia. As an example, the area south of Madrid, Spain, with annual direct normal irradiance (DNI) of 2,000 kWh/m²yr, is an excellent location, as is North Africa, where many sites offer DNI of around 2,500 kWh/m²yr.
Is there a minimum system size or minimum purchase requirement?
Technically speaking the smallest system has an AC nominal power of 6 kilowatts. However, concentrator photovoltaics is a large power plant technology and therefore projects range between one and hundreds of megawatts. For demonstration projects, though smaller units from 100 to 1000 kilowatts can be installed.
How much space is needed for a plant?
For a power plant size of 1 MWp, an area between 15,000 – 20,000 m² (1.5 – 2 hectares, 3.5 – 5 acres) is ideal in order to optimally lay out the system and to reduce shading.
Can I buy single modules from Soitec?
No. Soitec only sells complete systems, which include modules, inverters, and tracking systems. This is because the individual system components of a concentrator PV system must be factory-fitted to each other for optimal operation.
Can I install Concentrixmodules on my home or business rooftop?
No. Since the modules can only use direct solar radiation, they must track the sun using a two-axis tracking system. Therefore, they are not suitable for installations on buildings. In addition, the system is too big and too heavy to install on the roof of a house.