Fuel cell based hybrid power generation strategies for microgrid applications

A hybrid power generation system is a combination of two or more power generation sources to best make use of their individual operating characteristics and to obtain efficiencies greater than that could be obtained from a single power source. These hybrid power sources can be a combination of a fossil fuel based plant and a renewable energy source as in a gas turbine combined with a high temperature fuel cell based system or a combination of two or more renewable energy sources, like wind and solar. In this paper, hybrid power generation systems with different combinations of fuel cells and renewable energy sources for microgrid applications are discussed. The hybrid systems discussed in this paper are: combined cycle operation of a solid oxide fuel cell (SOFC) and a micro turbine; Proton exchange membrane (PEM) fuel cell and wind turbine; combination of SOFC and PEM fuel cell; and SOFC and solar thermal power generation system. The advantages and limitations of these strategies are also presented.