# Water harvesting from Soils by Solar-to-Heat Induced Evaporation and Capillary Water Migration

**Authors:** Xiaotian Li, Guang Zhang, Chao Wang, Lichen He, Yantong Xu, Rong Ma, Wei Yao  
**arXiv:** [1912.03273](https://arxiv.org/abs/1912.03273)  
**Date:** 2019-11-22  
**Summary page:** https://www.summarizepaper.com/en/paper/1912.03273v1/

## Key points

- Water scarcity is a major challenge for sustainable development worldwide.
- A team of researchers has introduced a new method for solar-driven water harvesting from shallow subsurface soils that could provide affordable freshwater in impoverished and arid areas.
- The process involves using concentrated solar energy to heat the soil and evaporate its moisture.
- The resulting vapors flow through tubes to a condenser where they condense into freshwater.
- Sustainable water harvesting is achieved through capillary pumping within the soil, which facilitates water migration.
- The experimental setup had a maximum water mass harvesting rate of 99.8 g/hour with total harvested water reaching up to 900 ml after approximately 12 hours.
- The entire process is driven by solar energy and does not require any additional mechanical or electrical components.
- With a 1 m2 solar concentrator under one sun energy flux (1 kW/m2), the estimated water harvesting rate is about 360 g/hour.
- This proposal offers an on-site and sustainable solution to address the global challenge of fresh water scarcity by tapping into potential huge reservoirs of shallow subsurface soils.

## Summary

Water scarcity is a major challenge for sustainable development worldwide. To address this global issue, a team of researchers has introduced a new method for solar-driven water harvesting from shallow subsurface soils that could provide affordable freshwater in impoverished and arid areas. The process involves using concentrated solar energy to heat the soil and evaporate its moisture. The resulting vapors flow through tubes to a condenser where they condense into freshwater. Sustainable water harvesting is achieved through capillary pumping within the soil, which facilitates water migration. The team tested their experimental setup in laboratory conditions and found that it had a maximum water mass harvesting rate of 99.8 g/hour with total harvested water reaching up to 900 ml after approximately 12 hours. The entire process is driven by solar energy and does not require any additional mechanical or electrical components. With a 1 m2 solar concentrator under one sun energy flux (1 kW/m2), the estimated water harvesting rate is about 360 g/hour. This proposal offers an on-site and sustainable solution to address the global challenge of fresh water scarcity by tapping into potential huge reservoirs of shallow subsurface soils.