How solar jerrycans are saving locals from diarrhoea, typhoid

Saturday March 21 2020

New technology. Mary Nakigudde puts the

New technology. Mary Nakigudde puts the Solvatten unit in the sun to heat water at her home in Bwaise, a Kampala City suburb, in January. Photo by DERRICK WANDERA 

By Derrick Wandera

Mary Nakigudde, 34, a resident of Bwaise, a Kampala City suburb, used to spend Shs2,000 every day on charcoal to boil five litres of drinking water for her family.

The single mother of four says she cannot risk giving her children un-boiled water after her first born son succumbed to an ailment doctors told her was related to drinking contaminated water.

“My son was three years and we used not to boil water because it is very expensive to do so. The doctors said he had died because of advanced typhoid and dysentery,” she reminisces the 2012 tragedy as she attends to her three-month-old daughter.

Nakigudde’s case is one of the more than 300 homesteads in Bwaise and other surrounding areas that have suffered from the problem of water-borne diseases due to drinking unsafe water and eating from dirty places.

Zam Byakika, the Bwaise chairperson, says many people in her area cannot afford to buy a sack of charcoal, which costs anywhere between Shs80,000 and Shs120,000.

“Our community has water sources but during the rainy seasons, they get contaminated by the running water that submerges them. This has made the outbreak of waterborne diseases rampant. Many people, especially children, have died as a result,” she says.


It is against this background that the Students Support and Philanthropy Programme (SSPP), an organisation charged with providing Water, Sanitation and Hygiene (WASH), through a partnership with Ikare, a UK-based organisation, are providing solar jerrycans dubbed Solvatten Units, which heat water to a boiling point in a short time and make it available for drinking.

Ian Calvin Waiswa, the director of SSPP, says a Solvatten unit is a portable water treatment device that doubles as a solar water heater.

“The sun’s energy inactivates pathogens through ultra-violent radiation, while also heating the water to provide additional disinfection. This water is very safe for drinking regardless of where it has been fetched from because the unit has the mechanism of treating it,” he says.

Waiswa says at least 360 homesteads are benefiting from the project and about 160 units have been supplied to the community in Bwaise.

“When we started the project in 2014, we provided 20 jerrycans for a pilot study, and after realising many people were benefiting, we brought in more 140 units. Some families have up to seven members and those who stay close each other share these jerrycans,” he says.

About the solar jerrycan
The Swedish-made jerrycan was invented by Petra Wadstrom in 2006, with a view of providing clean boiled water as a way of conserving the environment, which was being destroyed through charcoal burning.

Countries such as Kenya that adopted the technology in 2013, have made significant strides in solving environmental emissions. After four years of using Solvatten units, 22,000 tonnes of greenhouse gas emissions have been avoided, especially in the urban slums, according to United Nations.

The Solvatten unit is made with a black plastic material to absorb as much sun heat as possible. It holds at least 10 litres of water at a go, which is placed under intense sunlight and takes about three to four hours for the water to be ready for drinking.

Waiswa says: “It has two signals, one notifies you once you put in water and the other when it is ready for drinking. It has a button that turns red when you switch it on. When the water is safe for drinking, the light will change to green. On a very sunny day, it can heat 20 litres of water.”

If each of the 380 household which directly or indirectly benefit from the project has about 10 members, this means 3,800 people in Bwaise reap from this innovation.

Dr Emmanuel Mukwaya, a community health worker who runs a health centre in Bwaise, says there has been a significant drop in cases of diarrhoea and typhoid at his facility.

“Before these jerrycans came in, we used to receive about 30 patients in a day and out of these, 16 of them, especially children, were diagonised with either typhoid, hepatitis A, diarrhoea and gastro-enteritis-related diseases,” he says.

“Research has found that most of these organisms in the contaminated water can be treated with the ultra-violent light compared to the chemical reagents. Of course some people prefer to use the latter but the former is better. The jerrycans are also more affordable than any other method. I hope there is more capacity put into this initiative so that we can extend it to other places,” he adds.

Sylvia Nankabirwa, another beneficiary, says she not only saves money but time too.

“I always boil drinking water after cooking lunch. This means waiting further in the kitchen for the water to boil. But now, all I do is put the water in the jerrycan and relax,” she says.

Byakika says this initiative has mainly helped the women because of their nature of work and the fact that they are directly involved in child up-bringing in her area.
“Some of these women work in markets so they have to leave drinking water for their children,” she says.

Waterborne diseases in Bwaise

A survey conducted by Research Hub and Data Centre Africa in at least eight zones of Bwaise last year, indicates that more than two thirds of the 380 households that were interviewed had ever or were suffering from diarrhoea, typhoid or hepatitis A as a result of drinking unsafe water.
The report also indicates that nine out of the 10 homesteads they visited every day had a child or two battling the various illnesses.


Each Solvatten unit consists of two five-litre containers that have transparent surfaces and can be filled with water. The transparent surfaces of the containers are made from a plastic that allows the penetration of a large portion of ultraviolet light, specifically UV-B, which is highly effective in destroying microorganisms. Water is poured in through an opening that houses a filter of 35 microns to remove larger particles.

Once filled, the unit is placed in direct sunlight, which simultaneously heats the water and exposes it to ultraviolet radiation. The combination of these is an effective means of purifying water and, depending on conditions, the water will be free of pathogenic material in two to six hours. The water is heated to between 55 and 75 °C, making it suitable for a number of other household and hygiene purposes.