Floating solar PV to reduce water evaporation in water stressed regions and powering water pumping: Case study Jordan

Abstract

Water resources are essential for human consumption and food production. The extraction and delivery of water resources are highly dependent on energy. Hence water, energy and food security are inextricably linked, and this nexus constitutes a major global societal challenge. Furthermore, globally, irrigation constitutes around 70% of our freshwater resources, rising to 90% in developing countries. There are over 300 million drinking water and irrigation ponds globally where 90% of the world’s standing irrigation water resides. There is a need to conserve such resources, considering more than two thirds of the world’s population are currently experiencing water stress. Hence, this work tackles the conservation of such resources addressing two important issues related to energy and water, thereby addressing elements of the UN Sustainable Development Goals. Its considered approach is the use of floating solar photovoltaic (FPV) technology implemented on irrigation reservoirs to conserve water by reducing evaporation losses whilst providing sustainable electricity at enhanced yield that can be utilised locally. For the study, we selected an arid and water stressed region of Jordan where real-world water and energy consumption data were available. Various floating PV (FPV) system configurations were modelled for installation on an irrigation reservoir where currently no FPV exists. A fixed tilt 300 kWp FPV system was found to be the optimum design in terms of water savings, energy yield, economics, and reductions in CO2 emissions. Standard floating PV was deemed the preferred option compared to ground-mounted PV and FPV with tracking and/or active cooling. System payback period for the recommended design was 8.4 years with an annual greenhouse gas emission reduction of ∼ 141TCO2. For the considered site, around 12,700 m3 of water can be saved annually or 42% savings when compared to the uncovered reservoir. This research has wider applicability to other arid regions such as Africa, Middle East, and the Indian Subcontinent.