Modelling annual wave-induced loss for floating photovoltaics under realistic weather conditions

The installed capacity of floating photovoltaics (FPV) is growing, and deployment at more exposed locations, such as larger lakes and nearshore or offshore environments, is increasingly being considered. For FPV systems, the presence of waves will lead to movement of the PV panels, which in turn leads to variations in the incident irradiance. These irradiance variations, both in the average system irradiance and within a string of panels, cause a power loss referred to as wave-induced loss (WIL). Some studies have modelled WIL under different conditions, showing substantial variation in reported WIL values. Together with variability in the reporting of relevant parameters, this highlights a need for further modelling efforts, and for results to be presented with sufficient detail on site characteristics. Additionally, WIL depends on local irradiance and wave conditions, as well as the temporal correlation between them, which should be considered for WIL modelling. This study extends a previously published modelling framework to simulate WIL over a full year using site-specific and time-correlated sea state parameters and irradiance conditions. One-year simulations were performed for four nearshore locations along the Norwegian coast, yielding a WIL of 1.12% for the most sheltered location (with a median significant wave height of 0.22 m) and 2.28% for the most exposed location (with a median significant wave height of 0.52 m). The WIL was split into a component caused by changes in total received irradiance and a component caused by mismatch loss, showing that in this case the mismatch component makes up the majority of the WIL.