There is a growing number of lamps that generate electricity from water, whether it is distilled, sweet, or salty. The most recent breakthrough arrived from Argentina and earned a gold medal in the Safety category at the International Exhibition of Inventions in Geneva earlier this month. A compact cylindrical device, fed by water and producing no waste, can power emergency lighting in rooms and facilities. When deployed in multiples, these lamps can illuminate traditional living spaces as well.
Germán Nagahama Schell set out to rethink the classic galvanic cell, or Volta battery, by swapping its traditional components for water. He explained to Clarín that the goal was to improve a cell that avoids contaminants and makes use of water as the central medium. The core idea is to capture energy through a reversible chemical process that relies on water as the primary driving material.
The energy to generate electricity stems from electrolysis, a chemical reaction that requires three essential elements: a positively charged anode, a negatively charged cathode, and a driving force. In this concept, water acts as the working medium that links the two electrodes, pushing electrons along a controlled path to create light and power.
Yet ordinary water is not a strong conductor of electricity. To enable current flow, an electrolyte is often added. Electrolytes can be acids, bases, or salts, and they help dissolve or mobilize ions that ferry charge between the electrodes.
Remarkably, the inventor notes that the early experiments used acidic media due to their oxidizing potential. The development focused on enhancing that capacity while generating energy with water alone and without introducing extraneous materials, making the system simpler and more accessible.
Despite limited initial backing from electronics engineers, the project progressed through years of testing and refinement. The final design centers on a magnesium-based anode surrounded by a cloth impregnated with salt and encased by carbon fibers acting as the cathode. This arrangement reshaped the original concept into a cylindrical lamp, ensuring the cell remains salts-rich regardless of the water quality or the need for extra additives.
The lamp that won the prize is intended as an emergency lighting solution for hard-to-reach areas. It stands about 10 cm tall and closes into a 12 cm circle, with six LED segments at each end and assembled via simple screws. The design allows the cells to be charged with water, providing up to 15 hours of autonomy. The cell’s durability improves when kept wet only during use, reducing wear when not actively supplying power.
Beyond medals and diplomas, Nagahama hopes the recognition will attract both domestic and international patents, potentially boosting investment in manufacturing the lamp. The aim is to expand production while lowering pollutant emissions associated with traditional lighting systems.
Because the magnesium oxide in the cell can be used as an agricultural fertilizer and leaves no harmful residues, the technology presents an environmentally friendly alternative. This aligns with the inventor’s vision of practical, scalable applications that can be deployed quickly in diverse settings.
Remote or isolated places without reliable electricity access stand to benefit from this technology. By deploying several lamps, households and small facilities can achieve meaningful illumination, especially where current light output remains modest and resources are scarce.