The Fraunhofer Application Center Powerelectronics for Renewable Energy Systems in Hamburg is a subsidiary of the Fraunhofer Institute of Silicon Technology ISIT in Itzehoe and is in cooperation with the University of Applied Sciences Hamburg (HAW). Expertise of the Application Center is in the field of reliability and efficiency analysis for powerelectronic systems in applications of wind and solar energy as well as for e-mobility. New power electronic devices and improved circuit technology are in particular for quick charging and discharging of battery systems for renewable energy systems and e-mobility – e.g. electric aviation – an important challenge. To offer and develop customer tailored solutions, the Application Center has access to the knowledge and know-how of all the departments of the Fraunhofer ISIT such that expertise in adjacent research fields e.g. development of battery system is available. Work is done in the field of reliability analysis e.g. the evaluation and prediction of life-time for power converter. The Application Center develops highly efficient and reliable powerelectronic systems by employing innovative Semiconductors, new packaging technology and advanced control.