Households’ Willingness to Pay for Floating Solar Farms on Multi-Purpose Dam Reservoirs: Advancing South Korea’s Sustainable Energy Transition

Given South Korea’s acute land constraints and ambitious renewable energy targets, floating solar farms (FSFs) on multi-purpose dam reservoirs offer a sustainable land-sparing solution for advancing the water-energy nexus and climate adaptation. This study estimates households’ willingness to pay (WTP) for a tariff premium supporting FSFs on multi-purpose dam reservoirs—a bundled sustainability attribute encompassing land-sparing deployment, water-energy nexus synergies (90% evaporation reduction, hydropower complementarity), and avoided land-use conflicts—relative to equivalent electricity from land-based solar farms (LSFs). The valuation scenario explicitly frames FSFs as an integrated policy package, not an isolated engineering characteristic, with balanced disclosure of location-specific trade-offs. The study highlights the sustainability value of land-sparing water-energy nexus solutions in South Korea. The analysis draws on a nationwide contingent valuation survey of 1000 households conducted from mid-April to mid-May 2025. Employing the one-and-one-half-bound dichotomous choice format with a spike model to handle zero WTP responses, we estimate a mean tariff premium of KRW 26.8 (USc 1.9) per kWh—17% of the residential rate. This exceeds the current FSF-LSF levelized cost differential (KRW 19 per kWh), despite 49% zero bids largely from protest responses. Socioeconomic factors (education, income, female gender, metropolitan residence, policy awareness) significantly shape acceptance probabilities. These findings affirm meaningful support for FSF deployment, contributing to long-term sustainability by integrating renewable energy with water resource management and reducing land-use conflicts. They also inform sustainable energy transition policies by showing that consumers are willing to fund multifunctional infrastructure synergies.