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Petra Wadström - Founder of Solvatten

It is a chilly morning in Stockholm. Here, from a small, very cosy office, Swedish microbiologist and artist, Petra Wadström (1952), skypes daily with NGOs and governments from all over the world. Petra is the inventor of a cutting-edge water treatment and heating system, which has won many international awards and which is saving thousands of lives across the planet.


This enterprising woman has managed to harness the power of sunlight in order to purify and heat water for those who are in greatest need, especially those communities living off the grid. She has succeeded in designing a simple, but highly effective, system which is now improving the lives of many people in the developing world. This water treatment and heating system is designed like a 10 litre jerry can. Basically, it is a portable container which opens out into two halves, like a book. These sections have transparent lids which expose the water to direct sunlight and this simple procedure is the secret of her invention.


As the sun rays pass through these transparent lids, they break the linkeages of the DNA of toxic micro-organisms. As a result, the water becomes safe within a few hours of exposure. At the same time the warmth of the sun is absorbed by the can and it heats up the water to a high temperature thus making it safe for hygienic purposes. Midwives and doctors in Mali, Kenya and other African countries use Solvatten water for their medical procedures and operations.


Petra and her team know they are saving lives. They work tirelessly to reach those who live in challenging circumstances, such as those who are in refugee camps in countries like Jordan and Kenya. Despite her 67 years Petra is extremely active and bubbling with enthusiasm. She’s the kind of person who never misses the chance to talk to people at government level, or with embassies, aid agencies, NGOs and UN programmes in order to make her invention known and accessible to the most impoverished people in the world.



Last April, Petra was thrilled when a group of Sudanese women from the University of Ahfad signed a contract to take the Solvatten jerry cans to the rural areas of the country enabling Sudanese midwives to access safe water when they work. Further good news came during one of the most critical political turmoils of this East African country when, the long-serving ruler Omar al-Bashir, was overthrown. Since then Sudan has been embroiled in a political crisis. Security forces killed dozens of people last June in the capital, Khartoum. All this started about a year ago. Last December cuts to bread, together with fuel subsidies, led people to take to the streets in protest. Now, after months of instability, food security is compromised in this troubled Nile basin country. Petra is concerned. She has been following the events in Sudan closely for the past year. The first thing she says is: “many historical humanitarian crises start with a rise in the price of bread and very little is done”. In countries, where wood is still the main source of fuel, we can use the sun, which is free. In the Western countries we take our bread and water for granted, but in arid and semi- arid countries in the developing world, particularly in Sub-Saharan Africa, that comes at a huge cost to the environment. Earlier in the year we visited Kenya and talked to women who sold the bread they produced thanks to the hot water from the Solvatten jerry cans. The water which is treated by sunlight reaches the optimum temperature for yeast to rise. One enterprising Kenyan mother earns up to $300 a month by selling the bread she makes with Solvatten water. The money she saves is spent on firewood. Moreover, she has more profits and can spend more time selling her bread on the streets instead of looking for, fetching or buying firewood. In addition, she’s contributing to environmental protection by preserving trees and thus improving the lives of her children.


Is clean energy part of the big picture to end poverty?


Of course it is. For example, at Solvatten, we are committed to advance the 17 UN Sustainable Development Goals (SDGs). We tackle all of them. We work hard with aid agencies, development programmes, governments and NGOs to ensure that our technology is used in a positive sense thus creating a strong environmental and social impact. That said, it’s true that clean energy should play a bigger role in some of the SDGs. For example, with the SDG 6 (Water and Sanitation) the link between clean energy and hygiene is not being sufficiently addressed. In fact hot water fails to be an indicator in terms of hygiene in SDG6. The indicators used to show the progress of this goal focus on people having access to soap and water. However soap does not dissolve as well in cold water as it does in hot water, and cold water is unsafe when washing vegetables contaminated with parasites.


Why is hot water not included in the SDG6?


I don’t know, but I have raised this question many times. In fact the hygiene aspect in the SDGs is not well developed. This may well be because the link between water and energy has not yet been fully addressed. We have demonstrated that, by harnessing the sun, we can access hot water and this is something huge if we want to improve hygiene. In New Zealand, for example, a study was conducted in a school whereby some children used hot water and soap to wash their hands. Other children washed their hands with cold water and soap. Both groups were separated. It was shown that the number of infections was reduced when hot water was used. This is very simple. Not only does soap dissolve better in hot water, but children spend more time washing their hands with hot water. Also, washing vegetables with hot water is much safer for families, particularly if they want to avoid diseases related to intestinal parasites, etc.


But people can use iodine, chlorine or bleach to wash vegetables, can’t they?


When water is boiled or chlorinated it looses some of its most important properties. And we should remember that poor quality water affects nutrition. If children do not get enough nutrients they are more vulnerable to diseases. This is especially important for children under five years old. In Kakuma, Kenya, we carried out studies on how Solvatten water had affected public health and we observed that the number of intestinal parasites, cutaneous and ocular infections was reduced. In addition, the cold water with soap that is mentioned in the objective of sustainable development for water and hygiene does not take into account the main food washing cause of transmission of cholera and dysentery. In many cases, water is left under the sun to disinfect, which means that some micro-organisms continue to multiply. Often, in the discussions about access to safe water, it appears that too much attention is paid to giving access to improved water rather than to the actual quality of the water. This is noticeable when it comes to hygiene.


From the visits that you have made all over the world, which objectives have been met?


[Without hesitating Petra points to a photograph on the wall of a young African woman with a baby]. That picture is of a mother with her newborn baby in a village north of Bamako in Mali, just outside the maternity clinic. The water well that supplied this clinic previously was contaminated with parasites. Seeing the mothers return safely with their healthy babies was one of the most rewarding experiences I have ever had. I have four children and, as a  mother, I understand perfectly what it means to protect a baby. In these moments you realize that we are all equal, and that gives me a lot of energy to try to bring my invention to those who need it most. Hot water is still not on the agenda in sustainable development goals, but it is a crucial factor in the prevention of disease. I insisted on raising this issue when I was a panelist in the Nobel (Prize) Week Dialogue, which took place last year in Stockholm. We have also shown how NGOs can educate farmers on how to milk their cows with clean hands, in order to make the milk safer and last longer. 

This invention is designed for poor families who do not have access to running water or electricity. However, it costs around 90 euros and this may be relatively high for these families. How do you ensure that these jerry cans are affordable to the recipients?

The Solvatten jerry cans are usually marketed in a subsidized manner through international institutions, governments and NGOs because they have to reach the neediest. My non-profit company usually visits the projects in which the NGOs distribute the jerry cans in order to ensure that families can afford them and are making the most of them

Greta Thunberg has become a global icon for environmental activism and climate justice. You vindicated the concept of climate justice at the famous Climate Change Summit, COP21, which took place in Paris in 2015. You work with large Swedish corporations and international organizations. What have you learnt from your experience when connecting the economies of Northern Europe with the development challenges of the less developed nations ?


There are several low energy solutions aimed at generating enough energy to produce light or charge a mobile phone. But is that really what people in rural areas need? Or should we work harder to bring clean energy to help them refrigerate their food? Now to do this, you need to have enough energy to refrigerate food, to put a kettle on and then you need up to four solar panels or four sets of twelve batteries. All this relates to time. Women in developing nations should be freed from some of their time-consuming family burdens, of the time so that they can truly develop and become more empowered. In addition, access to hot water is a matter of dignity and it should be available to everyone. We need to listen to people and to understand what they really need. We must be more respectful and more humble.


In an interview with the BBC, you mentioned the importance of securing renewable energy resources for poor developing families. This included solar panels and water treatment systems like the one you created. Can your invention inspire people in developing counties to introduce more integrated systems of power generation and water treatment?


I have participated in numerous discussion panels in order to inspire future entrepreneurs to take advantage of solar energy. If there are problems, there must always be solutions, but these have to be modest. For example, at an Ugandan university, water is sold in glass, as opposed to plastic, and the water source was purified by solar energy. This kind of environmental care is extremely important.


Finally, if you were allowed to draft a global regulation for the United Nations on sustainable development, what would it do?


One of the fundamental points in environmental development relates to the search for gaps. When you draw a sketch, you must locate the gaps, the empty spaces. Imagine that you are you drawing a sketch for sustainable development; making time for women is one of those gaps, and values are the empty spaces, while the body of your plan would be the return of social investment. For example, in Mali, it was proved that cows that were able to shelter under shade of the trees produced up to four litres of milk, while those that did not have access to shade produced less than two litres. People need to understand that this issue of shade is crucial and valuable. These challenges are the consequences of climate change. In addition we have to protect the forests. When women in developing countries have more time they will be able to create a real impact. Basically, family burdens must be reduced so that woman can develop and be more empowered. There was a study in Canada, in the 1950s, which showed that women spent 56 hours a week doing housework. However, currently in Canada, they only spend 14 hours a week doing housework. But the Canadian situation of the 1950s still exists in many developing countries. The washing machine, for example, is one of the inventions that liberated women. The developing world needs the example of those women who have access to these labour and time saving devices.


A Microbiologist’s Journey Aimed at Saving Lives and Bringing Dignity


A trip to Indonesia changed the life of Swedish microbiologist and artist, Petra Wadström (a 67 year old from Stockholm) who had escaped from the long, gloomy Swedish winters and travelled to Australia with her young family. From there she grasped the opportunity to travel around many Southeast Asian countries. As a mother of four children she witnessed with concern, and at first hand, the appalling conditions in which disadvantaged rural women gave birth. At the same time, a question which had been with her for the years following her arrival in Australia kept on bothering her. The question was: ‘why not take advantage of the abundance of the sun to purify and heat water?’.


Following this, she began to put into practice her vast knowledge of microbiology. After years of research, laboratory work, and carrying out pilot studies, Petra found the solution to her problem. It is interesting to note that she had already worked at the Swiss University of Lausanne with Jacques Dubochet, who was awarded the Nobel Prize in Chemistry of 2017 for his work in the field of cryptology.


At first glance her invention is simple. It is a black jerry can which opens out into two halves, each half is protected by a transparent cover. So, once its drum is filled with water, it opens like a book and is then put in direct sunlight so that the water is exposed to the light coming through the covers. After a few hours the water is heated to an optimum temperature so that it can be safely used for surgical operations, simply because it is now free of toxic organisms and capable of maintaining the properties necessary for human health. Currently, Petra’s amazing invention is operating in twenty countries, and the United Nations distributes it in refugee camps such as the one in Kakuma, in Kenya and Azraq in Jordan.


Petra receives endless invitations asking her to participate in forums and on expert panels in places as diverse as New York, Qatar and Delhi. Despite her aimiable and straighforward persona, she is a woman who features in the Forbes list and who Barack Obama personally chose to talk about her ground-breaking invention. Most importantly, her creation has benefited more than 350,000 people worldwide and saved millions of trees.


Despite the positive global impact of her invention Petra remains uneasy with the situation facing those rural women in developing countries who she continues to visit regularly. The microbiologist is clear: sustainable development is only possible if women are given more time to themselves.


Author: Jordi Albacete





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