Energy and economic assessment of floating photovoltaics in Spanish reservoirs: cost competitiveness and the role of temperature

The installation of photovoltaic modules on water bodies, known as floating photovoltaics (FPV), addresses one of the main issues arising with the growing deployment of photovoltaics: land occupancy. However, while the FPV capacity is increasing exponentially, its economics is still being debated, as few field data are nowadays available and discussions on the expected performance are still ongoing. This work presents a first estimate of the maximum capital expenditures that FPV installers should target to make these systems as profitable as optimally tilted in-land photovoltaic (LPV) plants. The analysis is conducted by estimating and comparing the modelled Levelized Cost Of Energy (LCOE) and Net Present Value (NPV) of potential FPV and LPV systems in Spain. The analysis shows that low-inclination FPV systems are not expected to outperform optimally tilted LPV in terms of energy yield. However, FPV can already compete with LPV in Spain in terms of lifetime cost of electricity and profits if the expected lower operating temperatures are confirmed. The maximum allowed capital expenditure is found to vary depending on the location. The impact of factors influencing the energy and economic performance of FPV is also discussed, with particular attention to the effect of the improved thermal behavior expected from FPV systems.