Technology and Innovation

Through the concentration of sunlight (with our modules over 760 times), the active solar cell surface can be reduced to a fraction compared to conventional solar modules. This offers substantial cost savings due to reduced material consumption on one hand. On the other hand high-quality and expensive solar cells can be used, which, when concentrated, reach very high efficiencies.
A further important aspect is the use of special materials such as silicons, e.g. ELASTOSIL®. Further information on the website of Wacker Chemie AG in the article "Solar Power Moves in the Fast Lane".

	Slideshow SolCon™

The Sol*Con™-module development: Result of over 10 years development

A team of highly-qualified scientists of the Ioffe-Institute in St. Petersburg has worked for more than 10 years on the improvements of the Sol*Con™-module. During the years 2000-2004 the Fraunhofer Institute for solar energy systems (ISE) in Freiburg under the direction of Dr. Andreas Bett took also part in the development.

Crucial for this successful development were high financial subsidies in research and development by the Federal Ministry for Environment, Nature preservation and Reactor Safety (BMU).
SolarTec International AG has set up an exclusive partnership with the Ioffe Institute for the use of the attained results. Independently and in addition to the development by Ioffe/Fraunhofer SolarTec International AG has made further crucial development and has protected them through several patent applications.

Each wafer delivers up to 1,450 SolCon-high efficiency solar cells. Sol*Con-cells have a size of only 2x2 mm2 Impressive material savings: 0,02 m² Sol*Con-cells generate the same amount of electricity as an approx. 10 m² Si-solar modules.

Modules with up to 26 percent efficiency

Together with the Ioffe Institute in St. Petersburg, the Telekom STV in Moscow, the ENE in Brussels as well as further experienced partners, the R&D team of SolarTec International AG is presently leading the Sol*Con-technology to an industrial production stage. A pilot installtation with 1 KWp was set up already in 2005 in Berlin-Adlershof.

Sol*Con-dual layer III-V solar cells with efficiencies of approx. 24.5 percent were used in these plants. With these cells a module efficiency of over 18,2 percent can be obtained, resulting in a performance of 54Watts per module. To reach a performance of 1 KWp approx. 18 modules are needed.

Our future goal: Solar modules with over 28 percent efficiency

With its partners SolarTec International AG intensively pursues the advancement of both the solar cells and the entire system under the conditions of large scale production. International specialists assume that the triple- and quadruple-layer cells have a very high potential.

SolarTec International AG researches together with its strategic cooperation partners Ioffe-Institute in St. Petersburg and various companies on more efficient chemico-physical processes to enhance the efficiency of the conversion of sunlight into electric current.

The SolCon-Solar Concentrator System

On a long-term basis, due to high energy consumption and investment costs for new factories, a continuously sufficient production of solar silicon material for wafers is rather unlikely. This is also caused by the fact that silicon-wafers (receivers) can only transform a fairly small range of the light spectrum. Due to the quite big surface of flat-module-cells it is difficult to apply higher-order semiconductor-materials with substantially higher efficiency for the improvement of the exploitation of light.

However: If you concentrate the incident sunlight through inexpensive optics on a small surface, then you need only a small but efficient solar cell on this spot.
For such a focusing, fresnel lenses have been developed, which enable a concentration of light at a factor of about 2,000 suns. The basic pattern of the development is shown on the drawing on the left. If on the total area of a lens e.g. 10x10 cm (in Sol*Con-system already only 2x2 mm²) the arriving sunlight is concentrated by factor 760, the light is focused to a spot of approx. only 0.2 mm². Only on this small spot you then need a solar cell. The resulting high cell-temperature has to be dissipated immediately by a special construction. The heating up of solar cells has to be avoided, as per 10 degrees (celsius) increase causes a loss of cell efficiency by approx. 0.5%.
The researchers from the IOFFE-Institute in St. Petersburg (development partner of SolarTec International AG) have developed a special method. It dissipates the heat directly via a small metal plate directly connected to the solar cell. This method is highly efficient and realizeable at favorably low costs. The total system costs in relation to the efficiency can therefore be reduced by approx. 50%!