Main Participants: NIU Junkui, ZHU Junfeng, WANG Shifeng, YAO Jianan, WANG Xingtian, HOU Shiwen, LIU Wenbing, HUANG Yun

China has a vast territory of pastoral areas, primarily distributed in the northern and northwestern alpine regions. The pastoral areas are remote, with harsh natural environment, scattered settlements, lack of conventional energy, insufficient infrastructure, and primitive water supply facilities. Water pumping is mainly powered by gasoline and diesel generators, and local herders mainly carry water to their homes for daily use, leading to low convenience in water access. During frigid and long winter, livestock have to directly drink cold well water or lick snow and ice, leading to severe cold stress reaction that causes significant weight loss, reduced milk production, and constraints on the economic efficiency of livestock farming. At the same time, under sustained low-temperature conditions, blocking and crack frequently occur in water supply equipment and pipelines. The harsh environment poses even greater challenges to the already fragile water supply systems for both humans and livestock in pastoral areas, greatly impacting the drinking water safety and the healthy and sustainable development of livestock husbandry. Meanwhile, the vast pastoral areas are abundant in solar energy resources,which is favorable for utilization of solar energy technologies.

·   Developing photovoltaic water pumping technology that is directly powered by solar energy and automatically adjust load power without the need for power storage;

·   Achieving 24-hour water supply to herder households and enabling "one well for multiple households" while overcoming energy limitations and utilizing pressure tanks and other technologies;

·   Studying the use of free solar energy and information technology to achieve automatic  drinking and the supply of warm water during winter for livestock;

·   Studying the encapsulation forms of phase-change materials and the phase change-water combined thermal energy storage technologies that are complementary to thermal energy storage in water bodies;

·   Studying solar heating and anti-freezing technology based on phase change-water combined thermal energy storage, utilizing abundant solar energy for heating and anti-freezing of water supply facilities.

·   Having developed a specialized solar-powered water pump, enabling efficient matching between water pump and solar energy, resulting in an approximately 30% enhancement in system operating efficiency and a 18-25% increase in daily water pumping capacity;

·   Having overcome the limitations of traditional energy sources and developed a solar-powered water pumping technology without the need for power storage. The system can adjust load power in real time based on resource changes with a maximum pumping head of 200m and a flow rate of up to 30m³/h.

·   Having achieved intelligent warm water supply for livestock during winter by utilizing solar thermal technology for the first time. Having achieved automatic drinking control for livestock and zero energy consumption of system operation through machine recognition technology,;

·   Having formulated a phase-change material compatible with solar heat-collecting temperature, and encapsulated it within a water-based thermal energy storage system, increasing storage capacity to 200%. This maximizes the absorption and storage of solar heat energy, improving solar heat collection efficiency by about 6%;

·   Having studied the dual-vacuum superconductor heat collection and temperature-differential air evacuation technology to deal with the leakage in glass tube heat collectors under extreme cold conditions. Free and abundant solar energy has been utilized for heating and anti-freezing of water supply facilities, achieving energy savings of over 75%.

Since 2013, multi-scenario utilization of solar energy and intelligent water supply equipment for alpine pastoral areas have been widely applied in Inner Mongolia, Qinghai, Xinjiang, and other regions. With a total installed capacity of 1060kW, this technology helps guarantee drinking water supply of 7,424 herder households and over 285,000 livestock, covering 15,900 square kilometers of natural grassland. The results have been very significant and highly recognized by herders. This also brings an annual economic benefit of 20.406 million RMB, with a total economic benefit of 408.1205 million RMB in 20 years. It also yields significant social benefits, playing a crucial role in improving the quality of life for herders and ensuring border stability, rural revitalization and environmental protection.

Figure 1 Photovoltaic Water Pumping Project in Gangcha County, Haibei Xizang Autonomous Prefecture, Qinghai Province

Figure 2 Water Supply to Households Using Photovoltaic Technology and Pressure Tanks in Xilin Gol League, Inner Mongolia

Figure 3 Solar-powered Intelligent Constant-temperature Drinking Water Equipment for Livestock in Baotou City, Inner Mongolia

Figure 4 Solar Heating and Anti-freezing Project for Water Purification Room in Ulanqab City, Inner Mongolia