A techno-economic framework for dual-purpose wave farms: Integrating coastal protection benefits into the levelized cost of energy assessment

The dual use of wave farms in providing both coastal protection and renewable energy has gained attention as a promising strategy to reduce the high Levelized Cost of Electricity (LCoE) of wave energy. However, no techno-economic analyses have quantitatively incorporated the coastal protection benefits of wave farms into LCoE assessments, despite their potential to enhance economic viability. This study presents a novel techno-economic framework that integrates erosion mitigation benefits into the LCoE analysis. Sediment retention was quantified through long-term morphodynamic modelling, monetized using nourishment cost assumptions, and applied in an adjusted LCoE model. Results show that incorporating coastal protection benefits can reduce LCoE from a baseline of 193 €/MWh to as low as 115 €/MWh. Nourishment cost and discount rate emerged as influential factors, with site-specific conditions playing a key role in benefit magnitude. Sensitivity and uncertainty analyses were conducted to understand how these parameters influence the adjusted LCoE. Monte Carlo simulations showed that around one-fifth of plausible scenarios yielded LCoE values below 150 €/MWh, indicating that competitive costs are achievable under favourable combinations of financing conditions, OPEX, and nourishment valuation. This work advances the traditional LCoE analysis by including coastal protection co-benefits and provides a transferable methodology for evaluating dual-use wave farms. The approach has the potential to reduce the LCoE of wave energy projects, improve competitiveness relative to other renewables, and support the broader adoption of wave energy in erosion-prone coastal regions.