A team from US Naval Research Laboratory leaded by Philip Jenkins recently demonstrated a method for harvesting solar power underwater at depths of 30 feet. Due to this source of renewable energy underwater, long term installations of autonomous systems will have enough power to work properly.
As Jenkins says, this technology is meant to be “a new tool in the toolbox,” opening up further possibilities in renewable energy, and new options for powering underwater systems.
Up to now, the solar cells are capable of generating 7 watts of energy per square meter at depths of 9.1 meters, which is enough to demonstrate the technology’s potential for use in shallow water, such as in the areas near shorelines. Usually solar cells generate about 110-220 watts per square meter renewable energy.
The researchers needed a solar cells optimized to absorb the narrow wavelength spectrum of visible light underwater. Instead using crystalline silicon solar cells the researchers opted for high quality gallium indium phosphide (GalnP) cells that absorb wavelengths in the blue/green spectrum. This technology will be tested during long term deployment to better understand how water quality variation will affect performance of the solar cells.
This breakthrough has the potential to help everything from monitoring pollution levels to learning more about underwater creatures than ever before. Although underwater solar cells still have far to go before they are developed at the commercial scale.
