Preprint: Koami Soulemane Hayibo and Joshua M. Pearce. Foam-based floatovoltaics: A potential solution to disappearing terminal natural lakes. Renewable Energy (2022). 188, 859-872, https://doi.org/10.1016/j.renene.2022.02.085 1 Foam-Based Floatovoltaics: A Potential Solution to Disappearing Terminal Natural Lakes 1 Koami Soulemane Hayibo 1 and Joshua M. Pearce 1,2* 2 3 1. Department of Electrical and Computer Engineering, Western University, London, ON, Canada 4 2. Ivey Business School, Western University, London, ON, Canada 5 6 * joshua.pearce@uwo.ca 7 8 9 Abstract 10 Terminal lakes are disappearing worldwide because of direct and indirect human activities. Floating 11 photovoltaics (FPV) are a synergistic system with increased energy output because of water cooling, 12 while the FPV reduces water evaporation. This study explores how low-cost foam-based floatovoltaic 13 systems can mitigate the disappearance of natural lakes. A case study is performed on 10%-50% FPV 14 coverage of terminal and disappearing Walker Lake. Water conservation is investigated with a modified 15 Penman-Monteith evapotranspiration method and energy generation is calculated with an operating 16 temperature model experimentally determined from foam-based FPV. Results show FPV saves 17 52,000,000 m 3 /year of water and US$6,000,000 at 50% FPV coverage. The FPV generates 20 TWh/year 18 of renewable energy, which is enough to offset all coal-fired power plants in Nevada thus reducing 19 carbon-emission based climate forcing partially responsible for a greater rate of disappearance of the 20 lake. The results of this study, which is the first of its kind, indicate foam-based FPV has potential to play 21 a crucial role in mitigation efforts to prevent the disappearing of natural lakes worldwide. 22 23 Keywords: floatovoltaic; floating photovoltaic system; photovoltaic; water conservation; solar energy; 24 terminal lakes 25 26 Nomenclature 27 28  Total area of the FPV system (m²)  Albedo   Daily evapotranspiration (mm/day)   Incident solar irradiation (W/m²)  Atmospheric pressure (kPa)   Real vapor pressure of the air (kPa)   Output power of the FPV module (W)   Average saturation vapor pressure of the air (kPa)  Daily heat storage flux (MJ/m²/day)   Aerodynamic resistance (s/m)   Daily net solar irradiation (MJ/m²/day)   Global horizontal irradiation (W/m²) ℎ Relative humidity (%)   Air temperature (°C)   Dew point temperature (°C)   Effective operating temperature of the FPV module (°C)   STC operating temperature of the PV module (°C)   Water temperature (°C)   Wind speed (m/s)