Preliminary study of integrating the vapor compression cycle with concentrated photovoltaic panels for supporting hydrogen production

Although implementations of CPVs to support electrolysis to produce hydrogen have recently been established, they often neglect the heat component which is important to improve electrolysis efficiency. Therefore, this research proposes to integrate the vapor compression cycle to concentrated photovoltaic panels to form a combined heat and power system that efficiently supplies such required energy to a water electrolyzer to produce hydrogen. The vapor compression cycle is modified to selectively choose whether the waste heat should support water heating or be discharged into the ambient environment where the latter method is aimed to save power consumption. A preliminary investigation of the proposed system is conducted by analyzing a commercial concentrated photovoltaic panel and simple formulations such as the theoretical Carnot efficiency for the vapor compression cycle. Results suggest that the required compressor power in the vapor compression cycle is very substantial and caused the effective electrical efficiency to drop from 40% to 10% for condenser temperature of 360 K–410 K. Fortunately, the heat available by the vapor compression cycle is much higher than that demanded by water electrolysis. Thus, the modified vapor compression cycle with the selective heat discharge functionality has demonstrated hydrogen production rate improvements of up to 4%.