Multi-Criteria Site Suitability Assessment for Nearshore Floating Solar Photovoltaic Systems in the Gulf of Thailand: Integrating Hydrodynamic, Economic, and Environmental Factors
Copyright © 2026 Kornpaphop Ruttanawijit, Taweesup Desua, Yodchai Tiaple. Published by Nan Yang Academy of Sciences Pte. Ltd.
This is an open access article under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License.
Abstract
The paper provides a macro-level screening procedure for nearshore floating photovoltaic (N-FPV) suitability using province-level analysis based on Analytic Hierarchy Process (AHP)-Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) multi-criteria decision making supported by entropy objective weighting validation. The study assesses nine coastal provinces based on the following factors: irradiance, wave height, wind velocity, tidal range, coastal erosion, current velocity, proximity to existing grids, and industrial demand utilizing ERA5 reanalysis data (2019–2023) validated by 31 in-situ stations in the region. The inter-factor independence is confirmed with Pearson correlation analysis (|r| < 0.70 for all pairings), and asymmetric wind factor penalties are introduced to improve the physical realism of the ranking. Rayong (Ci = 0.741) and Chonburi (Ci = 0.682) are selected as tier 1 regions because of their high irradiance levels (5.15–5.29 kWh/m2/day), moderate waves (Hs = 0.48–0.52 m), and high-quality industrial infrastructure along the Eastern Economic Corridor. The results are further validated with ViseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) cross-checking, entropy weighting, demand proxy analysis, and criteria structure modification. The proposed approach shows strong stability to weight perturbations of up to ±22%. A techno-economic analysis of a 10 MWp system results in a range of Levelized Cost of Electricity (LCOE) values between $0.096–$0.111/kWh (Monte Carlo 50th percentile (P50): $0.097–$0.112/kWh). The scale analysis reveals a 12–18% reduction in costs per kilowatt of output at 5–50 MWp capacity levels. Project feasibility relies heavily on corporate power purchase agreements at or above $0.12/kWh; currently, the feed-in tariff is at $0.08/kWh, which leads to negative returns. Carbon credits can provide additional income. The results can be interpreted as provincial tiers before the actual screening of site locations; Geographic Information System (GIS) exclusion mapping and extreme-event studies should be considered mandatory.
Keywords: AHP-TOPSIS, Province-Level Pre-Screening, Eastern Economic Corridor, Levelized Cost of Electricity, Corporate Power Purchase Agreement, Marine Renewable Energy
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