On a sunny afternoon in Western Kenya, Eunice Shigali filled a 10 litre jerrycan with water, then unfolded it like a suitcase and placed it in the sun.
After a few hours, a green smiley face appeared on the side of the black container, telling her the water was clean and hot, and ready to cook ugali, a staple dish made of maize flour.
"I used to light a fire to boil water for drinking, washing and cooking," the 48-year-old mother of three told the Thomson Reuters Foundation.
"Now I save time because when I put water in the sun, I can carry on with my other chores … There is nothing that makes any woman happier."
Shigali refilled the portable solar-powered jerrycan from the well in her compound in Emuchimi village, and once again laid it in the sun to warm a second batch of water for washing.
Nearly a quarter of the world – some 2 billion people – lack access to safe drinking water, according to the United Nations.
About two-fifths of Kenya’s 46 million people rely on unclean water sources, such as ponds, shallow wells and rivers, particularly in rural areas and slums, says charity Water.org.
Shigali’s jerrycan is made by Solvatten – meaning "sun water" in Swedish – a Stockholm-based social enterprise that has been working since 2007 to boost access to clean water by selling its invention to governments, charities and businesses.
The jerrycan takes two to four hours to heat water to 75 Celsius (167 Fahrenheit) in the sun. Clear panels, when it is opened, also expose the water to the sun’s ultraviolet rays.
The combination of heat and light kill bacteria which can cause illness. A fabric filter also stops larger particles from getting in when filling it.
Previously, Shigali had to boil water for drinking and took cold baths. Using the jerrycan she uses less firewood and charcoal, which saves money and trees.
More than 300,000 people in 20 countries use the product, Solvatten said.
Its inventor, Petra Wadstrom, is one of Sweden’s most celebrated environmentalists who has won more than a dozen awards and featured in Vogue.
She had the idea 20 years ago when she saw women and children in Indonesia contracting waterborne diseases, like cholera and typhoid, from drinking contaminated water.
"I wanted to give women the power to be independent and have control of their daily lives," Wadstrom said in an interview.
"Even though they might not get a source of clean water, they could still purify the (water) they get from any source so it is safe for them to drink and use."
Shigali received her jerrycan eight years ago from the charity Soroptimist International, which now sells them to women across Kenya through 11 clubs, for 1,000 shillings ($10) each.
"We are working on ensuring that women are able to proudly have access to safe drinking water and be able to save a lot on fuel with just having to worry about the sunshine," said Dolphine Anyango, Soroptimist’s Kenya programme director.
The jerrycans are also being rolled out by businesses, such as Swedish coffee company Lofbergs, which has distributed them to improve the health of its Ugandan coffee-growers.
The jerrycans have also been offered as an incentive for mothers to visit clinics and vaccinate their children, said David Wadstrom, a spokesman for Solvatten, adding that the company aims to have a million people using them by 2020.
"You have to believe that there is a better life on the horizon for the most vulnerable people," he said.
"It’s really about not leaving people behind. Everybody should have access to clean, safe water at home."
Dominic Kirui is freelance journalist covering climate change, food security, culture, conflict, politics, gender and global development.