Theoretical Study on Direct Coupling of a PV Array to a PEM Electrolyser

摘要

Hydrogen is the most potential clean energy in the twenty-first century and can be obtained by the electrolysis of water.As a secondary energy,its production would be restricted by large amount of energy consumption and low efficiency.It is advantageous if an electrolyser can be simply and efficiently coupled to a renewable source of electrical energy.In this paper,it investigated the optimal way to maximize the transference of energy from a photovoltaic (PV) array directly coupled to a polymer electrolyte membrane (PEM) electrolyser in a photovoltaicelectrolyte hydrogen generation system (PV-hydrogen system).The pivotal strategy is to find the series-parallel combination of the PV cells and electrolyser stacks,which produces the highest energy transfer efficiency.The optimal configuration is a PV array consisted of three parallelconnected PV cells directly coupled to a PEM electrolyser consisted of twelve series-connected electrolyser stacks with a day energy transfer efficiency of 99.52％.Comparisons between direct coupling systems and conventional ones have been presented.The result shows that direct coupling technology is feasible to improve the energy transfer efficiency in a PV-hydrogen system.