Qi Zhu

The water resource problem faced by herders in Inner Mongolia is different from the traditional understanding of "water scarcity."

In popular perception, water scarcity often means a lack of clean water sources. However, the situation in Inner Mongolia is different—the region actually possesses a certain amount of water resources and is equipped with basic tap water infrastructure. The real difficulty lies in the fact that water resources are often very far from the herders' settlements, making the water collection process extremely cumbersome.

Herders typically need to drive trucks equipped with large water tanks to designated water replenishment stations or natural water sources to collect water, and then transport the water back to their homes for distribution and storage.

This process is not only complex and time-consuming, but also requires significant physical strength and fuel costs. On the grasslands of Inner Mongolia, besides water, all other resources are extremely precious, including fuel. To save on fuel consumption, most herders choose to use cow dung as fuel, and they conserve as much fuel as possible from driving.

To extend the lifespan of a single water supply, many herders choose to proactively reduce water usage, such as reducing bathing or other cleaning activities that require large amounts of water. This forced water-saving behavior has, to some extent, affected their quality of life and health.

Therefore, I designed this portable solar-heated water tank to improve the personal hygiene experience of herders.

My project consists of two main parts: a small trolley for easy movement and a water tank. The trolley has four wheels for mobility, and the open space at the bottom provides some stability on uneven ground. I also designed a foldable pull rod structure; when not in use, it can be folded up and placed on the edge of the trolley to reduce space usage.

The water tank measures approximately 30cm wide x 40cm long x 40cm high. Its actual capacity is approximately 30L. After testing, I found that common mini water pumps and portable electric showerheads can spray about 18 liters of water in 10 minutes, and the flow rate is more than sufficient for rinsing the body, which I think is appropriate.

This water tank also integrates storage functionality. Inside, there's a partition-like structure for holding bath essentials such as the shower head, hose, soap, shower gel, and shampoo.

The top lid also has a recessed area to hold these items while showering, preventing them from easily falling to the floor. This recessed area is highlighted in bright orange.

Two transparent windows on the side of the tank allow you to monitor the remaining water level.

The tank is black to better absorb solar radiation, especially ultraviolet rays. On a sunny day, exposing 18 liters of water to sunlight for 8 hours can raise the water temperature to approximately 35 degrees Celsius.