SolarSack is a water container, uses 4 hours of sunlight to kill organic contaminants in water, making it safe to drink.

The Jury says
This solution demonstrates high societal and economic impact with a technology that solves a great problem. The simplicity of just adding water to the bag is not groundbreaking but it works very well from a user’s point of view. We also note the clever use of materials in the transparent plastic sack.