What is Solvatten?


Clean and warm water at home

Solvatten is a combined portable water treatment and water heater system that has been designed for off-grid household use in the developing world. It is an easy, innovative solution that provides access to clean, hot water to people all over the world. Thanks to its durable design Solvatten is a low cost way to get clean, hot water.

Millions of primarily women and children need to walk dozens of miles each day to fetch water and firewood. Reducing the daily use of firewood and having a tool that can be used also on unimproved water sources closer to home makes life so much easier. Solvatten has an average lifespan of 7-10 years. That is the critical time when children are at their most susceptible to waterborne diseases.


Very simple, just add sun

It is well documented that solar energy can be an effective method of cleaning contaminated water. This is because ultraviolet (UV) light destroys the formation of DNA linkages in microorganisms, thereby preventing them from reproducing and thus rendering them harmless. Add the sun’s rapid heating of water and you have the exact process that occurs when Solvatten is used.

Solvatten makes water safe AND hot — up to 75°C/167°F. Water at this temperature is perfect for a number of household and hygiene purposes. Hot water is useful for cooking, hand washing, bathing and domestic cleaning. Once the water has been purified, an indicator tells the user when it is complete. The water will cool down quickly when in the shade ifcooler water. Solvatten can be used on partly cloudy days but not during heavy rain or thick cloud cover.



Opened like a book

Each unit contains two five-litre containers, each of which can be filled with water via an opening that houses a fabric filter of 35 microns.



Fueled by the sun

The unit is then placed in direct sunlight, which simultaneously heats the water and exposes it to ultraviolet radiation.



Purified by radiation

The combination of heat and UV light is a highly effective means of purifying water and, depending on conditions, the water will be free of pathogenic material in 2-6 hours.



Cleared to use

An indicator tells the user when the treatment process is complete – a sad red face changes to a green and happy one.


Very simple, just add sun

It is well documented that solar energy can be an effective method of cleaning contaminated water. This is because ultraviolet (UV) light destroys the formation of DNA linkages in microorganisms, thereby preventing them from reproducing and thus rendering them harmless. Add the suns rapid heating of water and you have the exact process that occurs when Solvatten is used.

Solvatten makes water safe AND hot — up to 75°C/167°F. Water at this temperature is perfect for a number of household and hygiene purposes. Clean and hot water is good for cooking, hand washing, bathing and domestic cleaning. Once the water has been purified, users can store the water in the shade and they will have cooler water. Solvatten can be used on partly cloudy days but not during heavy rain or thick cloud cover.


Water is everywhere, clean water is not

Lack of safe water, poor hygiene and poor health are daily challenges for millions of people living in poverty. Worldwide, 1 in 3 people live without reliable access to electricity and 1 out 8 people live without access to safe water.

Due to a lack of an energy infrastructure, people use natural resources, such as wood and charcoal, for cooking, washing and heating water. Up to 70% of the energy used by a typical home in Sub-Saharan Africa is used for these purposes. This strong dependence on natural resources lead to smoke inhalation, burn injuries, carbon dioxide emissions, and deforestation, which give rise to environmental problems. Indoor plumbing and secure electricity supplies are distant dreams for far to many people.

Daily challenges for people living in poverty


billion people globally use either an unimproved water source or an improved source that is faecally-contaminated (WHO)


billion people, 38% of the world’s population, are estimated to rely on the traditional use of wood and charcoal


million people lived on less than $1.90 a day (WorldBank)


million people die from illness caused by the air pollution from cooking over open fire


Changing habits, saving lives

The impact from the solar safe water heaters have been thoroughly measured from the start. A number of interesting findings have come to our attention. What stands out from other water treatment devices is that users have an exceptionally high ratio of uptake. Using Solvatten can be habitual. Health impact can be better achieved when a solution can address both human wants and human needs. High quality, smart design and aesthetic values is central for winning hearts: That is central for motivating people to changing habits and move towards something better.


Households with access to safe + hot water → improved hygiene → better health → better quality of life.


Using Solvatten impacts the everyday lives of individuals and entire communities. Furthermore, its impact extends to the environment that surrounds them. Solvatten contributes to reaching all of the 17 UN Sustainable Development Goals.

Here are some benefits with using Solvatten


Improved school attendance due to fewer sick-days and reduced reliance on children for domestic activities such as collecting firewood.


Reduced vulnerability of women and children, who are often responsible for collecting firewood from isolated areas of bushland.


Time saving, allowing people to persue more economically productive activities.


Solvatten tackles some of the underlying factors that keep people in poverty. It improves health and productivity; it saves money and time, therefore it helps people lift themselves out of poverty. (UN SDG 1)


Poor hygiene and lack of safe water play a big role in leading to and exacerbating malnutrition among children especially. Solvatten directly tackles water and hygiene related diseases, such as intestinal worms. The heated water makes the transition from breast milk easier and less risky. (SDG 2)


Since Solvatten can reduce the incidence of diarrhoea and other poverty related diseases away. Safe water and improved hygiene practices will reduce vulnerability to the major infectious diseases. (SDG 3)


Good health makes time for school. So will easing the heavy load for children to provide the household with firewood and water from distant water sources. (SDG 4)


The health benefits and the time and money saved with Solvatten will provide time for income-generating activities and give more girls the opportunity to go to school. Women are saving up to 3 hours a day when using Solvatten. Less time spent on finding fuel in unsafe locations means less exposure and incidence of gender-based violence. (SDG 5)


Apart from being a technology that purifies water to the higher levels than WHO guidelines sets out for safe water, Solvatten also recognizes the importance of heated water for hygiene and health. (SDG 6)


Solvatten runs on 100% green power, the sun. (SDG 7)


Using Solvatten will provide time and opportunity for income-generating activities. SDG8


Solvatten is bridging humanitarian aid and development while recognizing and utilizing the water-energy nexus, leading to resource efficiency. SDG 9


The notion and comfort of having safe, hot water at home is a distant dream for more than a billion people. Equality means equal access to the basics that create a dignified life. SDG10


Being energy and water efficient, Solvatten eases the pressures that increasing urbanization puts on energy and fresh water supplies. It also makes urban communities less vulnerable to utility service cuts and water- related disasters. SDG11


Solvatten improves water, energy, and time efficiency. SDG 12


Over 800 million households worldwide currently use solid fuels. For every one of these households CO2 emissions could be reduced by 1 ton per year if they changed from heating/boiling with solid fuels to using Solvatten. SDG11


By reducing CO2 emissions, Solvatten reduces ocean acidification which negatively impacts ocean ecosystems. Also plastic bottles can be used less when treating water at home instead. SDG 14


People have to coexist with very few resources which can lead to conflicts over water and fuelwood. Going solar with Solvatten is helping to drive down conflict by reducing people’s need for fuel, water and helping to build healthier families and communities. SDG 11


Since 2009, Solvatten has reduced the need to burn over 1,500 hectares of forest. SDG 15


Solvatten engages people, organizations and other companies throughout the world. This is creating awareness, practical action and business opportunities locally and internationally. What’s more, we do not work in developmental silos – but bridge development issues. SDG 16


About Solvatten

Solvatten works by incorporating three established methods for treating water;Filtration: water is poured in through a hole housing a fabric filter that catches larger particles. Heat pasteurization: heat from the sun warms up the water, killing pathogenic material. UV-disinfection: The high energy associated with UV sunlight causes damage to the DNA of micro-organisms, rendering them unable to reproduce or infect. Solvatten is therefore very easy to use: fill it up and lay it in the sun, then simply wait for the green smiley face indicator to show that the water is clean. What’s more, the simplicity and efficacy of these treatment methods make Solvatten highly reliable – see the technical questions below to learn more about the amount of contamination that can be treated.

Solvatten is a patented technology with a unique design that has many competitive advantages over other safe water solutions. Solvatten doesn’t simply treat water, it strengthens families, saves money for those who have little, and diminishes harmful environmental practices. Solvatten brings families the basic clean and hot water infrastructure that we all need – water for drinking, cooking and cleaning. 

Solvatten is both a limited company and a not-for-profit fundraising organisation, both of which share a combined mission to provide clean, safe and hot water in an environment friendly way to the many people living without it. Solvatten AB is a joint stock company owned by shareholders and managed by the inventor of Solvatten, Petra Wadström. Solvatten AB is responsible for producing Solvatten and selling to individuals, companies and organisations such as the UN and Governments.Solvatten Charitable Foundation focuses strictly on humanitarian projects that deliver practical solutions for people living without access to clean water. Solvatten AB supports the foundation and its campaigns by providing Solvatten units at a reduced cost. The Solvatten Charitable Foundation conducts fundraising and administers the donations received for Solvatten Safe Water Campaigns. The Solvatten Charitable Foundation is regulated by the Swedish County Administrative Board, which ensures the highest possible return on generosity, cost discipline and accountability.Donations made in the US are administered by the Solvatten Charitable Foundation USA, a registered 501(c)(3) organization. Contributions to Solvatten Charitable Foundation USA are tax deductible to the extent permitted by law. 

Sponsorship and purchase of Solvatten

Yes, simply click ”Donate” in the menu and take action.

We have a proud history of successful corporate partnerships with a wide range of companies – read about some of those projects here.Many of our partners use Solvatten as a means to reduce their carbon footprint, develop a corporate responsibility program or safeguard the health of employees working in developing countries. If you would like to initiate a corporate partnership, please contact us!

Yes! On the main menu at the top of the website you will find links to a webshop where you can buy individual Solvatten units. If you are interested in purchasing more units, or an entire pallet (72 units), please contact our sales team directly.

Technical and practical questions

Solvatten is designed to be robust and withstand the harsh conditions of where it is often used. One of the goals when designing Solvatten was to ensure that it would last the length of a childhood – i.e. beyond on the age of five, below which children are highly susceptible to the consequences of water related diseases. On average, a Solvatten unit lasts seven years, but if handled with care it can last much longer.

The amount of E-coli bacteria in a water sample gives an indication of its biological quality. The presence of E-coli indicates faecal contamination by people or other warm blooded animals, and the presence of other, possibly more dangerous, pathogenic organisms. To give an indication of scale and what is considered to be a safe contact level, the higher standard for bathing waters in the EU is less than 100 E-coli colonies/ 100ml, whilst the WHO safe drinking water standard is less than 1 colony/ 100ml.Solvatten has been tested using samples containing more than 200,000 colonies/100 ml – the results of this test showed that the treated water met the WHO’s safe drinking water standards of less than 1 colony/ 100ml.Furthermore, Solvatten belongs to an exceptionally small group of water treatment systems that can treat highly resistant forms of bacteria, viruses and parasites. USEPA certified tests conducted in California in 2014 showed that water treated by Solvatten reached the ‘Highly protective’ category, eliminating parasites, virus and E-coli. By comparison, chlorine and most filters are not able to achieve this level of protection.

The only part that may need replacing is the filter, which can be easily replaced with a folded piece of locally sourced cloth.We also recommend cleaning inside Solvatten periodically, so that it continues working efficiently. This is easy to do; simply add a handful of dry beans, rice or lentils and some water to the unit, before shaking and rinsing. Soft woollen balls are another alternative here. Do not use sand, as it may scratch the surface, and do not use detergents.

Solvatten’s dimensions are 36 x 47 x 13 cm, it weighs 2.70 kg unfilled and can hold 10 litres of water.

Safe, hot water is achieved in 2-4 hours when the sun is shining, 5-6 hours when it is partly cloudy. Under optimal conditions Solvatten can be used four times a day, producing 40 litres. Solvatten does not work effectively during heavy cloud cover or rain.

Solvatten works best in areas where there is lots of sunshine. Temperature is often not a limiting factor (we have used Solvatten in Sweden!) but warmth helps speed-up the purification process. Altitude does not affect useage, with many units currently operational in both mountain areas and lowlands.

Yes, people have found lots of innovative uses. For example, Solvatten is a popular tool amongst midwives who use the hot water when delivering babies.

Yes, the materials used to make Solvatten are fully approved by the FDA.

Yes, it is very straightforward and graphic instructions are printed on the unit. To date we have printed instructions in English, Spanish, French, Portuguese, Urdu, Hindi and Swahili.

Yes, however WHO recommends consumption within 24 hours for any treated water.

Solvatten is actively used by a variety of different sectors. For example, many schools, health centres, disaster-relief organisations and refugee camps own and use Solvatten every day.