Function:
A device which is able to convert undrinkable water into drinkable. It shall be able to purify and desalinate most available kinds of water with the power of the sun.
Development state:
Two working and performing prototypes are developed and in action and in daily observation for performance, practicability, durability and maintenance.
After testing several designs I came up with an enhanced version of a single slope passive solar still that is able to produce up to 2.7 liter of distilled water on a single day with an ½ square meter size.
The phase of product development is running. Current approach is to find the right materials and way of production to make it for shipping as light weight and stack able as possible.
Advantages:
– Low tech,
– no moving parts so far,
– all materials are almost every where available for DIY,
– and almost everything can be done by common tools.
– It is easy to understand, to maintenance and to repair.
– Solar still can also be used to collect rain water
Challenges to be solved and Limitations:
– The material which is in contact with the condensed water should be new, easy to clean and food grade.
– As the device is exposed to harsh UV sun light, heat, and high concentration of salt water, all materials should be carefully chosen and tested.
– The current approach to build with cement and garment takes several days due to cure the cement correctly.
– The device only makes sense in areas where some kind of water is available
– In order to make the glass tight laying on the box and make it airtight some kind of precision is needed to build
– as I am collecting simultaneously also rainwater with the same device it has shown that the rainwater can contaminate the condensed water output, and therefore be separated and filtered.
– the size of the device is already difficult/challenging to transport
– the find of the right materials takes time
Vision of impact:
The solar water still makes most sense for families and communities close to a steady water source like at the ocean, on small islands(powerful tool for small island development), but also close to contaminated rivers, lakes and mangroves. The source water should be roughly pre-filtered to reduce particles. It is also recommended to re-mineralize the condensed water. For people who are in a crisis situation with limited and no nutritious food supply, condensed water can de-mineralize the human body in addition.
At this moment I try to find a way of building it with garment and nylon fiber reinforced cement. The idea behind is to have a DIY give away package where the glass and cement can be purchased locally close to the place of need.
It also might be possible to produce a set of pre-cutted plastic sheets which can be assembled at the place of need and only the glass can be purchased locally.