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SolarSack: using the sun to purify water

In order to promote access to drinking water for people deprived of it, a Danish start-up has developed a solution for purifying water using solar energy.
SolarSack: using the sun to purify water
SolarSack: using the sun to purify water

SolarSack uses the SODIS method, a simple solar disinfection method that is 25 years old and recognized by the WHO, although the company has improved upon the concept. While SODIS uses solar rays and PET bottles to convert undrinkable water into potable water, SolarSack and its partner Bernhardt, a flexible plastic packaging specialist, have developed a reusable plastic pouch, a multilayer technological innovation that combines strength and transparency to allow the optimal spectrum of UV light to penetrate the water.

A simple, inexpensive and sustainable solution for the most disadvantaged people

Christened SolarSack, this flexible plastic pouch with a capacity of 4 litres must be placed on a roof in full sunlight where the combined action of UV rays and heat will - according to the World Health Organization - destroy between 99.9 and 99.999% of bacteria, viruses and other pathogens present in the water, making it fit for consumption. Weighing in at just 100 grams, the plastic pouch is designed to be easily transportable and storable. It can be reused 500 times and can purify 2,000 litres of water, the equivalent of the drinking water consumption of a family of 4 people for 1 year.

An enormous impact on global health and the environment

By developing this very affordable - a SolarSack costs less than two dollars - and energy-efficient solar water disinfection concept, SolarSack wanted to provide a solution for the 2.1 billion people worldwide who do not have access to clean drinking water. Serious diseases such as cholera, typhoid, dysentery, and more, linked to the consumption of contaminated water, cost the lives of more than 2 million people each year.

Purifying water by boiling it over a wood or charcoal fire remains the most commonly used method, but it is expensive, unreliable for consumers and very harmful to the environment, both in terms of CO2 emissions and deforestation.

First used in a refugee camp in Uganda in 2017, the SolarSack solution’s reach has since grown and it is now distributed in Kenya, Tanzania and more widely in East Africa. It will soon become available in more regions and will contribute to solving a global issue: access to drinking water.

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