Pitch
SolarSack can contain 4 liters of water, and with 4 hours in the sun, the water will be pasteurized, and ready to drink. With about 60 uses, a single SolarSack can provide more than 240 liters of water.
SolarSack is made to reduce shipping cost, and with a production price 1/5 the cost of a bucket of coal, SolarSack can be sold at a profit, and still be affordable to the user.
SolarSack is developed based on studies and prototyping in East Africa, and the both the purification process and the user interaction is tested with the actual users in Africa.
Calculation including shipping and distribution still gives SolarSack a 1/20 the CO2 emission compared to boiling with charcoal, while totally eliminating the use of wood.