Site selection of offshore wind-wave-hydrogen energy coupling system based on improved WHFS-TOPSIS: A case study in China

The offshore energy coupling system represents a promising direction for the future development of the offshore energy. Currently, the offshore wind-wave-hydrogen energy coupling system (OWWHECS) is the most promising project for application at the current stage, with a notable research gap in the employment of multi-criteria decision-making (MCDM) for its site selection. Herein, in this study, we innovatively use the weighted hesitant fuzzy set (WHFS) method to improve the technique for order preference by similarity to ideal solution (TOPSIS) method and construct a MCDM site selection framework tailored for the emerging OWWHECS projects. Initially, a comprehensive criteria system reflecting the unique aspects of the OWWHECS projects is developed across various dimensions. Subsequently, the WHFS is employed to gather criteria's evaluation data, followed by the application of the best-worst method and entropy weighting to assign both subjective and objective weights to the criteria system. The enhanced TOPSIS method is subsequently utilized to prioritize the alternatives, thereby increasing the precision of the rankings. Finally, the validity of the proposed framework is demonstrated through a case study of the offshore regions in Bohai Bay and the Shandong Peninsula, China.