Chinese scientists test underwater solar panels at sea

The development aims to address the power supply challenge for underwater sensors, cameras, and communication devices. Conventional silicon panels are ineffective underwater because the water column absorbs red light. The specialists created wide-bandgap lead halide cells designed for the blue-green spectrum, which penetrates into the depths.

In laboratory tests under illumination simulating a depth of 10 meters, a small photovoltaic cell achieved a power conversion efficiency of 34.71%, while a 28.79 sq cm module recorded around 29.4%. To protect against seawater, the structure was coated with a multilayer encapsulation made of butyl rubber, epoxy resin, and cover glass, while the stability of the crystal structure was enhanced using the chemical additive PHMG.

During sea trials off Weizhou Island in the South China Sea, the modules charged batteries by 1,416 mWh at a depth of 2 meters, 752 mWh at 6 meters, and 324 mWh at 10 meters over two hours of submersion. The stored energy was sufficient to power a connected LED panel.