Oases organisation is a charity foundation that installs water purifier technology that runs off solar (sun energy) to drought affected communities in Australia. The solar distiller changes water from dirty sources into clean water and is used to transform the local area into a productive, life supporting environment like an oasis.
The sun rays are concentrated into the vacuum tube by a parabolic mirror. Within the tube, it is in essence a distiller which converts water into steam which separates pure water from the impure source.
When it condenses again, it is pure water.