Clean water from the sun

SOLVATTEN

Two billion people – nearly 30 per cent of the Earth’s population – lack access to clean water at home. Solvatten, which means ‘solar water’ in Swedish, is the brand name for a clever black container. People pour dirty water into it, and clean water comes out. As the name indicates, the container uses solar energy to purify the water, destroying microbiological contamination, such as parasites and bacteria

The traditional way to purify water is by boiling. It has traditionally been considered women’s work. Often, children are expected to help with the time-consuming task of gathering firewood and kindling. Wood fires release carbon dioxide into the atmosphere and generate soot and smoke in homes, which are harmful to health. Burning wood also leads to deforestation, loss of biodiversity and soil erosion, because tree roots are needed to keep the soil stable. Research has shown that up to 70 per cent of all energy consumed in sub-Saharan Africa is used for boiling water.

In the late 1990s, Petra Wadström, a designer and artist and former research assistant, was living in Australia with her family. She also travelled around Indonesia and visited several developing countries in Africa. She was distressed to see how many people in those areas lacked access to clean water and suffered health problems as a result, but she was also determined to do something about the problem. The contrast between the overabundance of sunlight and the lack of clean water at those latitudes stuck in her mind.

Wadström was convinced the solution had to be small-scale and accessible for people in their daily lives. In order to work, it had to be extremely durable, with no expensive filters or other parts that needed to be replaced. And even more crucially, it had to be easy to use. She had seen too many examples of projects where people from wealthy countries told impoverished families how they should live their lives. Petra Wadström realised that if her idea was going to work, its design and marketing would need to show an understanding of and respect for the circumstances in which people would use it in their day-to-day lives.

Petra Wadström produced some prototypes and sure enough, UV rays and warmth from the sun destroyed microorganisms’ DNA,

Solvatten systems use the sun’s rays to purify and heat water, destroying harmful microorganisms. It saves time, especially for women and children. For Priscilla Lokisiau, a teacher from western Kenya, a Solvatten container also serves as a conversation starter for her pupils to discuss science and social issues.