Integrated DEA and hybrid ordinal priority approach for multi-criteria wave energy locating: a case study of South Africa

Renewable energy sources are seen as a sustainable solution to the problem of global energy security. Among the renewable energy sources, wave energy has great prospects for development in a few countries, including South Africa. However, South Africa's wave energy projects are still underinvested in practice compared to wind energy and solar PV. This paper investigates several questions related to the influence of both quantitative and qualitative factors on the effectiveness of wave energy projects (WEPs) and the appropriate placement for WEP in South Africa. For this purpose, a novel two-phase framework novel two-phase data envelopment analysis (DEA) supporting integrated multiple criteria decision-making (MCDM) framework is proposed. The first phase aims to identify potential locations for WEPs and calculate the technical advantage of these locations using the DEA model. In the second phase, other qualitative criteria, which affect the sustainable development of WEPs, are identified. Based on expert surveys, potential locations are analyzed and ranked by a novel integrated MCDM approach called OPA-EDAS. In the proposed approach, the advantages of the Ordinal Priority Approach (OPA) are utilized to simultaneously determine the weight of the criteria and prioritize the alternatives. However, the results of OPA depend on the priorities of the experts participating in the assessment. Therefore, this study attempted to overcome that by integrating the EDAS technique to assess the expertise. Furthermore, the DEA model is applied to increase the objectivity of the results. In addition, the robustness of the study's findings is validated by comparing the location with upcoming WEPs in South Africa. The result shows that the coast of Cape Nature Walker Bay has the most effectiveness for South Africa's WEPs.