A green hydrogen energy storage concept based on parabolic trough collector and proton exchange membrane electrolyzer/fuel cell: Thermodynamic and exergoeconomic analyses with multi-objective optimization

Abstract

With the continuous penetration of renewable energy plants into energy markets and their surplus power generation during off-peak periods, the need for utility-scale energy storage technologies is globally prioritized. Among the existing large-scale energy storage technologies, hydrogen storage has appeared as a powerful alternative due to its environmental benefits and the ability to store a large amount of energy for several hours to months. The major objective of the proposed research is to introduce a novel configuration of green hydrogen production for power generation during peak demand periods. In this regard, an innovative hybridization of a solar unit based on a parabolic trough collector with a proton-exchange membrane electrolyzer and a fuel cell is introduced and analyzed from the thermodynamic and exergoeconomic perspectives. Moreover, a sensitivity analysis and a multi-objective optimization based on the combination of neural network and grey wolf optimization algorithms are conducted to select the best working fluid of the solar unit and ideal operating conditions according to the minimum cost rate and the maximum exergy efficiency. The results indicate that Dowtherm™ A synthetic oil is the best working fluid, and the proposed system can generate 9, 14.9, and 20.1 MW of power during off-, mid-, and on-peak times, respectively. The results also show that the proposed system operates with an exergy efficiency of 17.6% and a cost rate of 492.4 $/hr under the optimal conditions.