By Abbas Nazil
Researchers at Nanjing University of Aeronautics and Astronautics have developed a floating droplet electricity generator (W-DEG) capable of converting rainfall into renewable energy using water itself as both the electrode and support structure.
Unlike traditional droplet electricity generators (DEGs) that rely on solid metal bases, the W-DEG eliminates the need for rigid materials, significantly reducing weight, cost, and environmental footprint.
The innovation, detailed in the National Science Review, generates up to 250 volts per droplet while floating freely on water bodies such as lakes or oceans.
Lead researcher Wei Deng described it as a “nature-integrated” design, emphasizing that the system directly utilizes the natural properties of water to produce electricity without heavy metals.
The W-DEG’s surface features a fluorinated ethylene propylene (FEP) film that reacts to raindrop impacts, triggering charge transfers that produce electricity.
Tests showed the generator works effectively with tap, lake, and even saline water, confirming water’s reliability as an electrode.
The floating generator costs roughly 106 yuan ($15) per square meter, less than half of conventional DEGs, and weighs only 0.5 kilograms — an 87 percent reduction in weight.
It withstood harsh conditions during field trials, including high salinity and debris, with simple cleaning restoring full performance.
Multiple W-DEG units connected together successfully powered 50 LEDs and charged a capacitor to three volts, enough to run small electronic devices or water sensors.
According to corresponding author Professor Wanlin Guo, the device represents a major step toward lightweight, scalable, and affordable clean energy systems.
The breakthrough opens pathways for “land-free” renewable power generation, especially for remote or aquatic regions where installing solar or wind systems is impractical.
By letting nature itself become both the structure and source, the W-DEG design opens a new frontier in sustainable, nature-integrated energy solutions.
