The Institute

With Interdisciplinary Competence for a Sustainable Energy Supply

Since its foundation in 1992, the Solar-Institute Jülich (SIJ) has been dealing with the development of application-oriented, technical solutions in the fields of renewable and efficient energy use.

A highly motivated, young team of more than 50 employees from various disciplines does research in direct cooperation with industry, universities and research institutions to ensure that the transformation path - away from fossil fuels and towards renewable energies - remains successful and affordable.

During this process, the SIJ can draw on the broad interdisciplinary knowledge of the FH Aachen - University of Applied Sciences. As a central scientific institution, professors from various faculties of the FH Aachen are involved in the executive board as well as in the research activities of the SIJ:


Technical Thermodynamics Prof. Dr. Spiros Alexopoulos
Building Services Engineering Prof. Dr. Bernd Döring
Combustion Technology Prof. Dr. Thomas Esch
Renewable Energies Prof. Dr. Ulf Herrmann (Executive Director)
Physics Prof. Dr. Doris Samm (Vice Rector for Research and Innovation)
Representative of the Staff Sebastian Steininger, M. Eng.
CAD Fachl. Dipl.-Ing. Georg Wählisch (Assistant Executive Director)

In addition, the Board of Trustees, consisting of personalities from politics, industry and research, provides consultancy services to the Solar-Institute Jülich. You can find more information here.

Executive Director of the SIJ

Prof. Dr.-Ing. Ulf Herrmann

Teaching Subject Regenerative Energien
Room N104
T: +49.241.6009 53529
F: +49.241.6009 53570
ulf.herrmann(at) | Homepage | Schedule of Events

Since 2014, the SIJ team has been headed by Professor Dr. Ulf Herrmann. Professor Herrmann has been involved in solar technology for more than 20 years, particularly in the areas of research and development as well as project management and organisational development. After his studies at RWTH Aachen University, he first worked scientifically at the Center for Solar Energy and Hydrogen Research in Stuttgart and obtained his doctorate at RWTH. He then switched to industry and worked for a technology supplier for solar power plants. During this time, he worked on the development and implementation of several solar thermal power plants in different countries. As chief engineer, he was involved in the realisation of the world's first commercial molten salt energy storage facility for solar power plants. Before joining the SIJ, he headed a branch office in the USA for more than two years.

Research and Services at the SIJ

The SIJ develops, tests and optimises various test benches, measuring technologies or software. A list of the equipment shows the versatility of the Solar-Institute.

Component Development

New developments are tested, qualified and optimised in extensive laboratory and outdoor facilities. The exclusive access to the Solar Thermal Demonstration and Experimental Power Plant Jülich (STJ, Solarthermisches Demonstrations- und Versuchskraftwerk Jülich) gives the SIJ a distinct unique selling point within the German and international university landscape.

Simulation and Modelling

Simulation programmes - commercial as well as self-developed - are used for conception, design, optimisation and system integration.

Studies and Concept Development

With the development of energy concepts and the production of studies, the SIJ accompanies the technology transfer and supports the analysis of the needs and requirements of the market.


Providing consulting services to industry and municipalities on efficient energy generation, distribution and use.

Education and Further Training

Training offers on the topics of climate protection, renewable energies and concentrating solar technology are continuously developed and implemented for the purpose of knowledge transfer (e.g. with Summer School Renewable Energy).