Quantifying the Saline Penalty: A Composite Degradation Framework for Techno-Economic Assessment of Floating PV on Coastal Shrimp Ghers in Bangladesh

Floating solar photovoltaics (FPV) have been deployed on freshwater ponds in Bangladesh, but their potential on the saline shrimp ghers of the coastal southwest remains unexplored. This paper proposes the Saline Penalty (SP); a transferable decision-support metric defined as the percentage increase in Levelized Cost of Energy (LCOE) due to saline-induced degradation. Using PVsyst simulation for a 101 kWp FPV system on a representative shrimp gher supplying Mostafa Organic Shrimp Products Ltd. (MOSPL) in Shyamnagar, Satkhira, Bangladesh, we develop a composite degradation framework informed by physically based degradation mechanisms from offshore PV literature. The framework incorporates salt deposition (0.05–0.13% annual acceleration), corrosion (transmittance loss from 91.46% to 70.35%), and biofouling using a multiplicative formulation. Uncertainty analysis via Monte Carlo simulation (10,000 iterations) quantifies the probability of SP exceeding the viability threshold. Results show the Saline Penalty ranges from 48.4% (optimistic, with mitigation) to 101.7% (pessimistic, without mitigation). Sensitivity analysis identifies viability thresholds: projects become economically unviable when SP exceeds ~60% (degradation >1.1–1.2% annually or CAPEX premium >17–18%). Monte Carlo simulation reveals a 34.4% probability of SP > 60% in the optimistic scenario and 100% in the pessimistic scenario. CO₂ avoided ranges from 95.7 to 116.3 tonnes annually. Based on the literature reviewed, this appears to be among the first studies to quantify the saline penalty for FPV in Bangladesh’s coastal ghers, providing a reusable framework for decision-makers evaluating FPV deployment in saline environments which is classified into four categories—Low (<20%), Moderate (20–40%), High (40–60%), and Critical (≥60%); enabling rapid decision-making.