Reservoir management by reducing evaporation using floating photovoltaic system: A case study of lake Nasser, Egypt

Abstract

The shortage of water is a major obstruction to the social and economic development of many countries, including Egypt. Therefore, there is an urgent need to properly manage water resources to achieve optimum water use. One way of saving available water resources is to reduce evaporation that leads to the loss of a large amount of water from reservoirs and open lakes. This paper aims to use a floating photovoltaic system (FPVS) to cover a lakes water surface to reduce evaporation and also for energy production. This methodology was applied to Lake Nasser as one of the largest lakes in the world where much evaporation happens due to its large area, arid environments, and the shallow depths of some parts of the lake. The estimated evaporation from the lake was 12.0 * 109 m3/year. The results show that covering 25%, 50%, 75%, and 100% of the lake can save about 2.1, 4.2, 6.3, 7.0, and 8.4 * 109 m3/year and produce energy of 2.85 * 109, 5.67 * 109, 8.54 * 109, and 11.38 * 109 MWh/year, respectively. Covering areas of shallow water depth was more efficient and economical. The results show that covering 15% of the lakes area (depths from 0.0 to 3.0 m) can save 2.66 * 109 m3/year and produce 1.7 MWh/year. Covering 25% of the lakes area (depths from 0.0 to 7.0) can save 3.5 * 109 m3/year and produce 2.854 MWh/year. Using an FPVS to cover parts of Lake Nasser could help manage water resources and energy production for Egypt to overcome the likely shortage of water resources due to population growth. This system could be applied in different locations of the world which could help in increasing water resources and energy production, especially in arid and semi-arid regions.