Turning Seawater into Light


Oct 11, 2022

Colombian renewable energy start-up E-Dina has manufactured a cordless light that can convert salt water into electricity.

Electricity provides economic opportunities and a great quality of life. According to the WHO, at least 840 million people around the world lack access to electricity. This limits their working beyond daylight hours, performing essential tasks or staying connected with the world. Additionally, many areas also lack access to emergency services.

Colombian renewable energy start-up E-Dina has manufactured a cordless light that can convert salt water into electricity. This is a more reliable alternative to solar lanterns in communities that are off the grid. This portable device is called WaterLight.

The light consists of a cylindrical case made of Urapán wood. There is a circuit integrated into its base and a perforated cap on top that performs a dual function - Water can flow into the device and hydrogen gas formed as a by-product of the ionization process can escape.

It just needs to be filled with 500 milliliters of seawater – or urine in emergency situations – to emit up to 45 days of light based on the kind of usage its users put it through. It acts as a mini power generator. The device can also be used to charge a mobile phone or another small device via its integrated USB port, or to power a small radio, fostering a sense of connection within the confines of a small community and even to the world at large.

In the process, the salt and water get separated and salt particles get evaporated. The lamp can be emptied and refilled and the water that remains in the light can be used for cooking, washing, or cleaning.

The initial project was planned as a stand-in for solar energy, which is highly used for supplying remote locations but which is weather-dependent. WaterLight can be more efficient than solar energy lanterns because of its instant regeneration feature. Once filled with water, the energy delivery is instant as contrasted with solar lanterns which need to transform solar energy to alternative energy which charges batteries. Solar lanterns only work if there is sun.

It works 24 hours a day through ionization, which sees electrolytes in the saline liquid react with magnesium and copper plates on the interior of the lamp to produce electricity. It is a long-established process, but E-Dina has developed a way to sustain the chemical reaction over a prolonged period of time so that it can be used to power a light source.

Throughout its lifetime, one light can generate around 5,600 hours of energy, which translates to two to three years of use depending on how often it is needed. The product can be purchased by NGOs, governments and private organizations for distribution as needed.

This current iteration of the lamp was designed specifically for the Wayúu people, an indigenous tribe living on the coastal desert at the northernmost tip of South America. The region suffers from poverty and regions don’t really have access to electricity because they're a population that's been forgotten by the government. This technology is a solution for coastal communities with no access to electricity.

"This generation of WaterLight was inspired by these traditions and the Wayúu artisans made the straps with their own hands," said Pineda.

Each light is expensive to make -- around $60 to $100 each (whereas solar is far cheaper), but the technology is more reliable and charges up the lights instantly, something solar power is unable to do. With electricity demand expected to increase by 70% by 2035, and traditional fossil fuels estimated to be depleted in the next 52 years, a solution is urgently needed. ENPOSS as an organization applauds sustainable energy generation ideas that are eco friendly and that curtail fossil fuel usage.