Boundary-layer parameterization for assessing temperature and evaporation in floating photovoltaics at the utility-scale

A precursor model for parameterizing the effects of photovoltaic powerplants on the atmospheric boundary layer is developed using computational fluid dynamics. The method allows one to compute the surface roughness lengths, aerodynamical resistances of covered surfaces and convective heat transfer coefficients, adapted for any photovoltaic module layouts and wind directions. It has been applied for two setups: a wind tunnel system and a utility-scale floating photovoltaic installation. In these cases, the altitude-based velocity profiles was reproduced over the arrays; and we found that the turbulence generated by the photovoltaic/atmosphere interaction is greater for head- and tailwinds than sidewinds, therefore affecting the environment and the photovoltaic system. Constructing a digital twin of the floating array using large-scale meteorological fields and the parameters of the precursor model, the temperature of a monitored module was calculated and a spatial variation of 1.3°C /km and 5.8°C /km was estimated at the utility scale. Moreover, the waterbody evaporation was reduced by 40%–50% due to the photovoltaic panels blocking the vapour removal processes. This result decreased to 14%–20% when considering the flow spatial variations across the waterbody. Further research is necessary to adapt the parameterization to scenarios with low wind velocity.