Making drinking water safe with sunlight

Solvatten is a combined portable water treatment and water heating system that has been designed for off-grid household use in the developing world. It was the brainchild of Swedish inventor Petra Wadström, who saw the potential of using sunlight to create water containers that would clean contaminated water.

The container is a large Jerry Can that opens in half in the same way a book does. The material heats with the sun to 75°C. The ultraviolet (UV) rays produced by sunlight destroy the formation of DNA linkages in microorganisms, preventing them from reproducing and rendering them harmless. When the water is good to use a green smile appears.

The product is targeted at families with children under five years old, and lasts 7-10 years. It is also supplied to midwives to provide water for washing mothers and babies.

The Solvatten solar heater warms the water so it reduces the energy required for cooking; it can be mixed with nutrient powder to create a safe porridge for young children; and improves hygiene by enabling hand washing before cooking and eating.