Floating Offshore Solar Energy on the Spanish Coastline: an Economic Viability Assessment

Abstract

[Abstract]: Offshore floating solar energy is an emerging renewable technology with significant potential in countries with high solar resources, such as Spain. This study evaluates the techno-economic feasibility of a 13 MW offshore floating photovoltaic farm based on Ocean Sun platforms across the five Spanish maritime demarcations defined in the Maritime Spatial Planning (MSP). Capital expenditure (CAPEX), operation and maintenance costs (OPEX), Levelized Cost of Energy (LCOE), Internal Rate of Return (IRR), and Net Present Value (NPV) were analyzed under different electricity tariff and equity cost scenarios. The results indicate that project profitability is highly sensitive to electricity prices and financing conditions, with higher tariffs and lower equity costs leading to improved economic performance. Among the analyzed regions, the Canary Islands showed the highest energy production potential and the most favorable economic results, with an average LCOE of €189.74/MWh. In addition, geospatial feasibility maps were developed to support strategic decision-making for offshore solar deployment in Spain. Overall, offshore floating solar energy is identified as a technologically viable complementary solution to more mature offshore renewables, such as offshore wind, although its economic performance remains highly dependent on electricity prices and financing conditions.