Uganda: using sunlight to clean water

Nali Evarline Bwire from Uganda used to have to cut down a tree before she could quench her thirst without risking her health: ‘I chopped wood and made a fire to boil my drinking water,’ she explained, which entailed a great deal of work every time – work that Bwire no longer needs to do. Instead, she now uses sunlight to kill off the germs in her drinking water. To do so, Bwire fills up PET or glass bottles and lays them in the sun. After a while, the natural UV radiation kills viruses and bacteria. Bwire uses a WADI device to check the water. WADI stands for water disinfection. The measuring device runs on solar power and is placed next to the water bottles, allowing users to track the progress of disinfection: ‘If I look at the WADI after a few hours and see a smiley face, the water is drinkable,’ Bwire explained. The smiley face does not appear until enough sunlight has been measured to reliably neutralise germs.

Thanks to the project, 25,000 people from more than 5,000 households in rural Uganda now have access to clean drinking water. Bwire is delighted about the direct health benefits from the WADI device: ‘My children no longer have rashes and diarrhoea caused by contaminated water.’ More than two thirds of the devices were handed out to women and girls, who particularly benefit from them. In addition to the health aspects, the devices also make their everyday lives easier, as they no longer need to gather firewood. Nali Evarline Bwire is using the time she now saves to reforest her land: ‘Now I plant trees instead of burning them.’ 

The solar water disinfection project in Uganda is part of the Strategic Partnership Technology in Africa (SPTA) launched by the German Development Ministry (BMZ). The Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH has teamed up with the local organisation Get Water to support the project. The WADI devices are provided by the SPTA partner Helioz.

The SPTA brings European companies together with development cooperation stakeholders to develop public-private cooperation projects in African countries. The aim of projects is to contribute to meeting global sustainability targets through selective use of pioneering technologies. GIZ is cooperating with more than 220 European companies within this network, which particularly focuses on the areas of education, energy, health, green technology, agriculture and mobility.

A video on selected SPTA projects, including the solar water disinfection project in Uganda, is available here.