Soitec Solar
Founded in 2005 as Concentrix Solar GmbH, this spin-off company of Fraunhofer ISE was acquired by Soitec in 2009, an international market leader in the development and production of innovative materials for the semiconductor industry and pioneer in the field of energy and electronics. With the acquisition of Concentrix Solar, Soitec entered the market of concentrator photovoltaics (CPV) and became a leading manufacturer of CPV power plants. The key technologies of Soitec Solar were Smart Cut™, Smart Stacking™ and Concentrix™. At the end of 2015, the company Soitec Solar ceased production in the field of photovoltaics.


Holotools GmbH (now temicon GmbH - holotools)
Our business is the design and the realisation of functional surfaces for light management and other applications. Holotools was founded in 2001 by engineers and scientists of the Fraunhofer Institute for Solar Energy Systems. Extensive technological know-how has been developed in micro optics, lithography processes, micro patterning techniques and optical design. A strong focus has been set on the realisation of uniform microstructures on large areas without any seam lines - the key success factor for the commercial use of microstructures in many applications.


SorTech AG
In April 2002 SorTech AG was founded as a spin-off of Fraunhofer ISE and the UFE Solar GmbH. SorTech AG aims to explore heat sources for cooling and therefore use low temperature heat as an energy source in place of electricity. SorTech systems provide cost-effective and environmentally friendly cooling. Now, a system technology is available that takes the excess heat from a variety of thermal sources, especially during summer, and converts it into useful cost-effective cooling. The named thermal sources include district heating, solar systems and motors as well as all types of waste heat that are generated in many different types of production processes.


PSE AG, founded in 1999, has specialized expertise in solar testing methods and solar knowledge management. PSE has experience in building solar testing facilities, delivering solar consulting projects and organizing solar conferences. PSE is closely linked to Fraunhofer ISE, particularly in the area of solar testing.

Solar Building Engineers Association for Energy Planning mbH

Solares bauen GmbH emerged in co-operation with the group Solar Building at Fraunhofer ISE. The engineers in the company came from Fraunhofer ISE as well as planning offices. The close link between practice and research offers the customer a particular advantage. Since it was founded in 1999, the company has specialized in the efficient use of energy and on all renewable energy sources. The main priority of the company work is to create an optimized and comfortable indoor climate. The correct mix of energy conservation and energy supply provide the customer with the best result.


SolarSpring GmbH
SolarSpring GmbH, based in Freiburg, Germany, was founded in February 2009 as a spin-off company of the Fraunhofer ISE. In arid and semi-arid regions the lack of drinkable water often corresponds with a high solar insolation. This favours the use of solar energy as the driving force for water treatment systems. The main scope of the company is the development, construction, production and distribution of solar powered water treatment systems and particular membrane distillation and reverse osmosis systems for desalination, membrane filtration systems for purification and disinfections systems. However, the overall objectives are decentralized autonomous systems for remote areas; the supply of water to decentralized areas from water sources like seawater, salty (brackish) well-water, contaminated or dirty surface water (rivers, lakes, wells). Beside SolarSpring is active in non-solar driven water treatment with membrane distillation and ultrafiltration, industrial process water treatment and supply with either high purity water or higher concentrated solutions.
SolarSpring GmbH


Enit Energy IT Systems GmbH
Enit Energy IT Systems GmbH was founded in September 2014 as a spin-off of the Fraunhofer ISE. The company develops and markets monitoring and control systems for decentralized energy systems like combined heat and power plants, photovoltaic systems or industrial consumers. These systems help customers gain more transparency about their electricity, heat and gas consumption. In addition, the company’s products enable intelligent system control and more efficient operation. The internally developed technology, called OpenMUC, adapts itself to the customer’s system and remains flexible for adaptions in the future.
Enit Systems GmbH