Researchers from Yunnan University in China have developed perovskite solar cells capable of generating electricity at 10 meters below the ocean surface, according to a study published in the journal Joule.
The team first built a test system to simulate sunlight penetration at various ocean depths. Using the resulting data, they developed a perovskite cell optimized for blue-to-orange wavelengths — the specific light spectrum that penetrates deepest into seawater. The cell was then scaled up to a commercially viable module size.
Mounted on an underwater robot, the module produced 324 mWh of electricity in two hours at 10 meters depth in saltwater. While modest in absolute terms, the researchers said the result exceeded expectations for a first real-world test. The energy output is sufficient to charge a small lithium-ion battery or power an LED light.
The researchers estimate the module could operate for approximately 5.5 years at 10-meter depth in saltwater. They plan further tests to increase power output and determine the maximum depth at which the cells can function.
Potential applications include powering autonomous underwater vehicles performing infrastructure maintenance, communication buoys, underwater cameras, and environmental sensors. The researchers also envision providing ships with power outlet buoys to reduce reliance on climate-damaging diesel generators.
China has been aggressively expanding offshore solar capacity, with the province of Jiangsu alone launching a 27-gigawatt offshore solar program. The underwater cell technology could complement these surface installations by extending solar energy generation into the ocean depths.
