The transition of the electrical power system from centralized power generation to distributed generation without fossil and nuclear fuels is the great challenge of the next decades for the energy sector. Complex technical ever-changing issues have to be investigated by researchers and energy companies.The NEIS 2017 was the fifth conference "Conference on Sustainable Energy Supply and Energy Storage Systems". The NEIS provides a yearly occasion for scientists to present their current work. It is organised by the Chair of Electrical Power Systems of the Helmut Schmidt University/University of the Armed Forces Hamburg. In 2017, the NEIS was technically co-sponsored by the German chapter of the IEEE Power and Energy Society.