Solar Oven Converts Salt Water into Fresh Water

Solar oven being tended by owner. Photo courtesy: © Gabriele Diamanti

Anyone who reads this blog knows that I have several hobby horses that I like to trot out on a regular basis. One of those issues that is near and dear to my heart is the accessibility of fresh water to all who live on this planet. I am delighted to say that another small step in bringing affordable, clean drinking water to all peoples has been taken. Read on.

As a graduate student, Italian designer Gabrielle Diamanti's travels exposed him to the global water crisis and the issue became a fascination for him. Fortunately he's been able to use his skills as a designer to create something that could make a big difference for those with little access to clean water. The Eliodomestico is an open source design for what is essentially a solar still, but with thoughtful details to make it even more functional and easy to use for those in coastal areas where salt water is abundant, but fresh water isn't.

Technology doesn't always have to be complicated, sometimes the simplest materials and concepts are the best. The Eliodomestico works like an upside-down coffee percolator to desalinate salt water. The ceramic oven has three main pieces. The top black container is where the salt water is poured. As the sun heats the salt water and creates steam, the pressure that builds pushes the steam through a pipe in the middle section. The steam condenses against the lid of the basin at the bottom and then drips into the basin, where it is collected.

The oven can make about five liters of fresh water a day. The UN refugee agency states that refugees need a minimum of 7 litres per person per day, just to survive. In the arid regions where many of the displaced are forced to seek shelter, they need more. And to ensure minimum standards of health and sanitation, they need 20 litres of water per person each day.

The design can be built for about $50 and although Diamanti used terracotta for his prototypes, local craftsmen can use whatever materials are most abundant where they live. The basin is also designed to be comfortably carried on the head, which is common in sub-Saharan Africa and other places around the world.

Solar still technology is old and not uncommon to find in developing nations, but it's often on a much larger scale, like at hospitals or water desalination plants that serve entire communities. Diamanti wanted to create this open source project so that individual families could have access to the same desalination process in a simple-to-use format.