2024 - LIGHT TO WATER

The Mongolian region, with its abundant solar energy resources and unevenly distributed water resources, is facing a pressing issue. Global climate change has led to water-related disasters such as floods, droughts, and water shortages, which are constantly threatening the livelihoods of nomadic herders. To cope with this, herders have been resorting to annual groundwater extraction, a practice that has led to severe environmental issues. This project, therefore, is not just a solution, but a necessity, aiming to utilize the abundant solar energy resources to address the urgent water scarcity issues in water-deficient areas of Mongolia.

Water scarcity among Mongolian herders primarily occurs during winter and spring. During summer and autumn, the pastures are often located near rivers, providing herders ample and stable water sources. However, in winter, herders must move to hilly areas away from rivers where grass has had a year to grow and where they can seek shelter from the wind. Water sources for winter herding mainly rely on snowfall, with excessive snow cover leading to ”white disasters” and insufficient snowfall resulting in ”black disasters.” Summer droughts also affect the growth of grass in winter pastures, leading to shortages of fodder for livestock. This unpredictability poses significant challenges to herders, destabilizing their livelihoods. Therefore, addressing winter water scarcity is crucial for the Mongolian region, requiring reliable alternatives to water resources to meet herders’ daily water needs during winter and to nourish winter pastures during droughts.

The Mongolian region boasts abundant solar energy resources, making it suitable for utilizing solar energy technologies to solve water resource issues. In addition to existing methods such as river water, precipitation, and groundwater utilization, atmospheric water vapor can also be effectively extracted and utilized. Considering the harsh winter conditions in Mongolia, we propose a solar-powered adsorption water vapor extraction device. This device efficiently extracts water vapor from the air by cyclically using saline water and stores it in a water storage area. The solar power generation section continuously generates electricity and stores it in batteries in the equipment area. It provides energy for water pumps and electric heaters to operate the device under low-temperature conditions. The evaporative area serves as the roof of the active area in the device, refracting sunlight through real-time water flow, casting water’s shadow into the interior, and providing solace for water-deficient herders.

The device consists of a solar power generation area, water absorption area, evaporative area, equipment area, and water storage area. The evaporative area contains sufficient highly saline water capable of adsorbing water vapor. The water pump in the equipment area draws this highly saline water to the water absorption area composed of semi-permeable membranes to absorb water vapor. After absorbing water vapor, the diluted saline water returns to the evaporative area. The evaporated water vapor is condensed and collected in the water storage area for subsequent use by herders to nourish nearby grasslands during droughts.