Underwater Perovskite Solar Cells Operate at 10 Meters in South China Sea Test

The paper, published in the journal Joule, describes lead halide perovskite cells modified with a polymer called polyhexamethylene guanidine hydrochloride. According to the research team, the cells deployed 10 meters underwater collected enough energy to charge a set of lithium-ion batteries within two hours. The same devices are expected to operate for about five and a half years at a time.

Power output declined noticeably with depth. The cells captured 1,416 milliwatt-hours of electricity at a depth of two meters, falling to 752 milliwatt-hours at six meters and 324 milliwatt-hours at ten meters, the researchers reported. In separate laboratory tests, the panels reached a power conversion efficiency of just under 35 percent.

Wen-Hua Zhang of Yunnan University said previous studies of underwater solar cells had been limited to very shallow water depths of only two meters or less, a scenario far from meeting practical application requirements. He described the work as the first functional validation of submerged solar cells operating at a water depth of up to about 10 meters, which he said greatly broadens their application scope.

The intended role for such cells is to power devices that remain stationary for long periods, including sensors, cameras and communications systems, potentially reducing the need for human intervention to maintain power supplies.

One unresolved question is how the panels would interact with the marine environment. They are likely to accumulate biomatter that could impede operation and require regular cleaning, a process known as biofouling, since the sunlight that powers the cells can also encourage the growth of plants and animals.

The authors wrote that the work paves the way for the practical deployment of perovskite photovoltaics in underwater environments, describing it as a promising route toward self-sustained marine energy systems and autonomous underwater devices.