This is the third version of our solar water still. In addition to simply taking the heat from the sun during the day to evaporate and distill feed-water, it can also ‘take the heat’ from a charcoal or other waste fire (to produce water even at night or in the rainy season).

This particular unit is developed to be a simple and cheap ‘do-it-yourself’ solution that can be made by pretty much anyone pretty much anywhere, for very little money.

The evaporator is constructed from a standard corrugated iron roofing sheet embedded in a frame of chickenwire-reinforced -cement. Very heavy but very, VERY strong... The top surface is coated with cement mixed with charcoal powder which gives a nice, black, porous surface from which water evaporates easily....

The condensator is a simple glass/sealant box affair (aquarium-style) with a drain made from a glass strip emptying into a small rubber tube.

It stands (optionally) on two halved oildrums in which a fire can be ‘stoked’ to heat the evaporator from below.

It easily makes 4-5 liters of the purest, nicest, drinking water, per sunny day..... And with a small fire lit underneath it, it can make about half a liter per hour....

The feed water in the evaporator reaches a temperature of 75-80C. And the concrete stays ‘warm’ for several hours after sunset (or fire burning out).

The objective, in partnership with the YE Water Program, is to create a ‘pictorial’ manual that can be published online and provided freely to various community groups, in conjunction with a ‘hands-on’ workshop.

With a simple ‘over/under-pressure’ air-circulation system, the productivity of the unit might be boosted to over 10 liters per day and an automated tanks/, feed/rinse system might be added at very little additional costs.