Modelling wave-induced losses for floating photovoltaics: Impact of design parameters and environmental conditions

Abstract

The interest in floating photovoltaics (FPV) as a land-sparing alternative has been rapidly growing over the last few years. So far, most of the installed FPV systems are inland on relatively calm waters. However, with the expanding market, FPV is moving to nearshore and offshore locations. There, larger waves can be expected resulting in a need for evaluating the impact of wave motion on the performance of FPV systems. Wave-induced movements of the PV panels can lead to varying irradiance levels, also within the string of panels, causing wave-induced loss (WIL). In this work, we have developed a model to simulate WIL for FPV systems. The model consists of three main modelling steps, wave-structure-interaction modelling, irradiance modelling and electrical modelling, where the second step has been experimentally verified. In the model, the in-house software 3DFloat is used to simulate the movement of the PV panels, and existing python libraries are used for the irradiance and electrical modelling. With this method, WIL has been simulated for different scenarios, to study the influence of different locations, sea states, times of year, string lengths, tilt angles and wave directions. The simulated WIL varied greatly with the chosen conditions. As an example, the WIL ranged from 3.3% for a significant wave height of 0.25 m to 6.7% for a significant wave height of 1 m.