Primary use of the cooker is to heat water to 160+F for the full day as a means of sterilizing both it and the container.
Build a simple solar cooker into the side of each hut using the same building materials as the rest of the unit (i.e., reflective insulation boards).
- Sterilisation is effective against biological contamination however it will not remove heavy meatal contamination.
- If the water temperature is less than 160F then bacterial growth will increase rather than killing bacteria off. Reliable indicators that the water has been fully treated, are being worked on by a variety of groups.
- Also, I do not suggest cooking on the Solar cooker as a core technology. General field reports seem to indicate solar cooking doesn't go over terribly well in many areas.
- The aim of this is to capture solar heat and concentrate it in the water. This conflicts with the general cooling strategy for the Hexayurt, which is to reflect as much solar heat as possible and prevent it from being captured. Better would be to place the solar cooker facing away from the Hexayurt, towards the sun. Then it will intercept solar energy that would have hit the Hexayurt and direct it towards the water.
Cost & Materials 
The financial model is based on $10 or less per household for one solar cooker.