Integration of a vanadium redox  ow battery with a proton exchange membrane fuel cell as an energy storage system

The proton exchange membrane (PEM) fuel cell is a green energy producer which converts chemical energy to electricity in high yield. Alternatively, the vanadium redox  ow battery (VRB) is one of the best rechargeable batteries because of its capability to average loads and output power sources. These two systems are modeled by Nernst equation and electrochemical rules. An effective energy generator should be able to operate with a new type of energy storage mechanism which would increase the capacity and stability of the comprehensive system using the proposed integrated system. Therefore, in this presented study a VRB as an energy storage system along with a PEM fuel cell has been modeled for peak shaving purpose. A transient model was created as a novel approach to predict cell operation condition, based on electrochemical equations and the battery equivalent circuit concept. Results showed that charging the VRB for one day with surplus produced electricity from the fuel cell will increase the total delivered power of the integrated system up to 50%.