Solar-Enhanced ocean thermal energy conversion for green liquid hydrogen production

A design, simulation, and optimization of a solar-enhanced ocean thermal energy conversion system for the simultaneous production of power and liquid hydrogen are proposed. This study explores a novel approach to enhancing ocean thermal energy conversion performance by integrating solar thermal collectors with nanofluids, thereby augmenting the exergy efficiency and system economics. Incorporating solar thermal flat plate collectors with nanofluid as an additional heat source increased power generation through the organic Rankine cycle. EES software performs thermodynamic modeling, while data analysis uses artificial neural networks. The multiobjective grey wolf optimizer algorithm is enacted to ascertain the most advantageous operational parameters for the chosen working fluids of the organic Rankine cycle (R134a, R245fa, R290, and R600). The TOPSIS decision-making method was then applied to assess and contrast the performance of working fluids. The findings revealed that R245fa emerged as the supremely optimal working fluid, exhibiting the best performance among the options considered. It achieved a peak exergy efficiency of 12.62 % alongside a maximal mass flow rate of liquefied hydrogen production reaching 25.53 kg/h. The total investment rate is minimized to 383.38 $/h. The associated study offers a foundation for further investigating and commercializing ocean thermal energy conversion technology in the hydrogen energy sector.