The German electricity system is currently undergoing a transformation. Market liberalisation, the necessity for power plant replacement, environmental regulation and new technologies (like renewable energy carriers and decentralised power generation) drive the process. The interdisciplinary TIPS project Transformation and Innovation in Power Systems - TIPS investigates possibilities to guide this transformation into a more sustainable direction. The research focuses on socio-technical innovations as a key factor in shaping the course of transformation. TIPS is a contribution to the Socio-ecological Research Framework (SÖF) funded by BMBF from 2003 to 2007.