The cooperation of fuel cells and renewable energy sources: A short review of operated energetics systems and their main deficiencies of PEMFC models in hybrid systems

The hybrid system represents energetic block that consists of individual energy sources. Furthermore, it has other devices that are necessary for reliable operations of the system as a whole. The hybrid system often combines the cooperation of several energy sources which work on different physical principles. Therefore, there are a lot of concepts of hybrid systems in the world nowadays. The review informs about current modelled and used hybrid system concepts in the energetics. Individual concepts can have not only energy sources that produce electricity but also thermal energy sources. Moreover, either the system can be connected to the distribution network or not. The implementation of these energy sources and other devices depends on a specific system concept and its operation requirements. The review is mainly focused on the systems which contain low-temperature proton exchange membrane fuel cells (PEMFC) cooperating with renewable energy sources in grid-off systems. Deficiencies of PEMFC models are pointed out in this paper as well.