BlueSkyWater uses a StrawBaleStill

BlueSkyWater uses a StrawBaleStill which is a low temperature solar still to make fresh water from salt or polluted water.

PV powered pumps in the sump of the still insulated with straw bales (or similar) pump the brine/ polluted water though clear PVC tube on matt black trays which are covered with clear acrylic.

The UV kills any bacteria & heats the brine/ polluted water. On return to the sump, it gives off vapour. On the ceiling of the still is another coil of pvc tube carrying cold brine from a tank at a higher level. This condenses the vapour which drops to a drip tray & out. The condensing brine/ polluted water in return gets preheated before dropping in the sump.

Excess hypersaline brine/polluted water continuously escapes from the unit. Both it & the fresh water leave through tube-in-tube PVC heat echangers up the middle of which runs a smaller tube carrying cold brine to the sump. It arrives preheated – both the condensate & the hyper saline leave cold – so keeping the heat in the still and maximising the output.


Solar still – with foil covered wall behind, for winter heating

Straw Bale still

PVC tube laid in a matt black tray

pvc coils

solar  tracker

2 dimensional, manual solar tracker – for the sump pumps