PHOEBUS—an autonomous supply system with renewable energy: six years of operational experience and advanced concepts

Abstract The PHOEBUS demonstration plant has been supplying the Central Library of Forschungszentrum Julich (FZJ) with solar-generated electric energy all year round and independent of the public grid since 1993. The central task was to test the required storage using hydrogen as the energy carrier in conjunction with an electrolyser and a fuel cell under realistic irradiance and consumption conditions and to demonstrate the feasibility of such a zero-emission supply system. The general objective was to determine weak points from the operating experience and measured data obtained, to model the system in a component-oriented manner for simulation, to energetically optimize the plant, to achieve high operational reliability and, above all, to propose and implement cost-reducing and advanced system modifications. With the aid of validated simulation programs, it was possible to carry out optimization analyses for plant operation (annual scenarios) and plant configuration. Two advanced concepts were developed: PHOEBUS-2, a simplified system with reduced energy losses, and PHOEBUS-3, a wind–PV hybrid system supplying both electricity and heat. The advanced concepts PHOEBUS-2 and PHOEBUS-3 are the theoretical basis for applications such as a solar home system, a solar village, a scientific polar station or a storage module for grid-connected operation that can be realized in the near future.