Made by high-quality gallium indium phosphide (GaInP) cells, which have a higher efficiency under low light conditions, new solar panels developed by Scientists at the U.S. Naval Research Laboratory, Electronics Science and Technology Division can be used to power sensors or autonomous research devices designed to monitor ocean environments.
In the current days, underwater autonomous systems and sensor platforms are hugely limited by the lack of long endurance power sources and must rely on on-shore power, batteries or solar power supplied by in land platforms. Attempts to use solar PV have had limited success due to the lack of penetrating sunlight. However, although the intensity of solar radiation underwater is lower, the spectral content is narrow and thus lends itself to high conversion efficiency if the solar cell is well matched to the wavelength range.
”The use of autonomous systems to provide situational awareness and long-term environment monitoring underwater is increasing. Although water absorbs sunlight, the technical challenge is to develop a solar cell that can efficiently convert these underwater photons to electricity.” said Phillip Jenkins, Head of NRL Imagers and Detectors Section.
Preliminary results at a maximum depth of 9.1 meters reveal 7 watts per square meter of solar cells were collected, which is enough energy to power a small AUV used by the laboratory for researching underwater ecosystems.