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

This article focuses on developing a multi-criteria decision-making (MCDM) framework for site selection of offshore wind-wave-hydrogen energy coupling system (OWWHECS) projects. It introduces an improved technique for order preference by similarity to ideal solution (TOPSIS) method extended with weighted hesitant fuzzy sets (WHFS) to better capture expert evaluations and uncertainties in criteria assessment. The framework integrates subjective weights from the best-worst method (BWM) and objective weights from the entropy method to prioritize potential sites, demonstrated through a case study of offshore regions in Bohai Bay and the Shandong Peninsula, China. Results highlight economic factors, especially initial investment cost and proximity to ports, as critical criteria, and the WHFS-TOPSIS method shows greater sensitivity and reliability compared to other ranking methods. The study addresses a research gap in OWWHECS site selection by providing a comprehensive criteria system and a novel decision-making approach tailored to the unique characteristics of these emerging renewable energy projects.