Energy yield, degradation and economics of reflector-enhanced floating and land-based photovoltaics

This study evaluates fixed-tilt reflector-assisted floating photovoltaic (FPV) and land-based photovoltaic (LPV) systems at Kremasta Lake, Greece, through a coupled analysis of irradiance, shading, thermal response, PV-module and reflector degradation, technical lifetime, maintenance, and economics. For a reflector tilt of 10 ∘ , the maximum first-year energy yield occurs at a PV tilt of 43 ∘ and an initial reflector reflectivity of ρ 0 = 0.95 , providing annual energy gains of 18.41% for FPV and 17.86% for LPV relative to their respective optimal reflector-free configurations. Reflector-enhanced irradiance increases module temperature, with a maximum hourly temperature-induced efficiency penalty of 3.84% for the 10 ∘ reflector configuration. The maximum annual PV degradation rate increases from 0.89% to 1.26% yr –1 for FPV and from 1.17% to 2.45% yr –1 for LPV under the most severe reflector-assisted conditions. Consequently, at the first-year energy-optimal configurations, the modelled PV technical lifetime decreases from 26.03 to 18.57 years for FPV and from 19.97 to 9.98 years for LPV. When material-dependent reflector ageing, cleaning, replacement, and technology-specific O&M costs are included over a 20-year project horizon, the economic optimum shifts to ρ 0 = 0.75 . The minimum FPV LCOE decreases from 46.59 to 45.90 EUR/MWh, whereas the corresponding LPV LCOE increases from 46.50 to 47.49 EUR/MWh. These results demonstrate that the reflector configuration maximizing first-year energy is not the configuration minimizing lifetime electricity cost, and that reflector integration is economically more compatible with FPV than with LPV under the investigated conditions.