The temperature of floating photovoltaics: Case studies, models and recent findings

• Published in: Solar energy Vol. 242; pp. 234 - 245
• Main Author: Micheli, Leonardo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-08-2022
• Subjects: Cooling; Floating photovoltaic; Literature review; Operating temperature; Thermal models; U-value; Thermal models; Literature review; U-value; Floating photovoltaic; Cooling; Operating temperature
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2022.06.039

•The literature available on floating photovoltaic (FPV) temperatures is reviewed.•Water-cooled FPV are expected to achieve lower temperatures than air-cooled FPV.•The thermal behaviour of FPV varies depending on the design and the local conditions.•Wind is the main cooling agent for FPV systems installed above water surface.•More experimental and comparative studies on the topic are recommended.
In floating photovoltaics (FPV), modules are installed on water to alleviate the land requirement of this energy source. In addition, FPV installations are expected to work at lower operating temperatures compared to land based photovoltaic (LPV) systems, thanks to the cooling effect of water. If confirmed, these lower temperatures would (i) increase the energy yield and (ii) reduce degradation and performance losses, boosting the cost-competitiveness of FPV. However, some recent works have reported cases of FPV systems working at higher temperatures than co-located LPV systems. The present review gathers the literature on the thermal behaviour of FPV, outlining the models and discussing the currently available experimental results. It is found that FPVs of different configurations can experience different thermal behaviours, not always necessarily better than LPV. In particular, air- and water-cooled FPV systems should be always distinguished, considering their diverse cooling mechanisms. Initial comparative analyses make it possible to identify designs and conditions that can favour the heat transfer in FPV compared to LPV. The role of additional factors on the FPV temperature, such as the PV material or the more frequent biofouling, is also discussed. Last, estimations of the economic impact of the thermal behaviour on the FPV costs and competitiveness are presented.