A Hydrogen-Storage Distributed Generation System Using Unitized Reversible Cells and Its Operational Scheme

Environmental issues such as global warming and depletion of natural energy resources are posing problems. Photovoltaic systems have been attracting attention as a form of renewable energy. The output power of a photovoltaic system changes sharply because solar radiation intensity and temperature vary with the weather. In conventional photovoltaic systems, the surplus power, excluding the power consumed in the load, flows back to the grid. Therefore, fluctuations in the output power of a photovoltaic system may have an adverse effect on the grid. This paper proposes a novel hydrogen-storage distributed generation system using a unitized reversible cell that integrates a fuel cell and water electrolyzer to smooth reverse power flow. The hydrogen-storage distributed generation system was modeled and a computer simulation was performed. Using two evaluation methods, the proposed system is shown to be effective at leveling power flow back to the grid.