A new approach to solar desalination for small- and medium-size use in remote areas

A conventional solar still produces 6 litres of fresh water per square metre per day of collector surface. With heat recovery and air mass circulation we can reach up to 20 litres m3/d. The quality of the processed water is always very high so that the investment costs are justified. This depends on the material used and the price of the solar stills. The advantage of the solar still is independent water production at the point of use and no need for trained maintenance staff. The high working temperature solves most problems. Small, modular high-performance stills with features like the possibility of decentralized use, less maintenance and robust construction can help to reduce sweet water scarcity. Small solar stills for fresh water production were not able to compete in the past because they were too expensive for producing less than 6 litres m3/d of fresh water. The recent development of stills based on new concepts for stream-leading and heat recovery has been successful.