Scientists at the US Naval Research Laboratory, Electronics Science and Technology Division recently announced that they have developed a new breed of underwater solar panels that are able to power submerged electronics and sensor systems. You might think that solar cells would have limited use underwater due to the limited amount of sunlight that is able to penetrate the murky depths, however these new panels are optimized to produce a significant amount of power at depths of up to 9 meters.
The Navy developed the underwater solar power system to power sensor arrays that are currently reliant on on-shore power, batteries or solar power supplied by an above-water platform. The intensity of solar radiation is lower underwater and the spectral content is narrower, so the team fine-tuned the cells to the available light wavelength range to produce a higher conversion efficiency.
Instead of using traditional crystalline silicon solar cells and amorphous silicon cells, the naval team used high-quality gallium indium phosphide (GaInP) cells, which work better underwater. GaInP cells have a higher quantum efficiency in low light conditions where wavelengths run between 400 and 700 nanometers.
Initial tests at a maximum depth of 9.1 meters revealed the cells’ output to be 7 watts per square meter of solar cells, which was deemed to be a success. The Navy has now opted to harness solar power at depths commonly found in near shore littoral zones to power a range of systems.
In a press release from the US Naval Research Laboratory, Phillip Jenkins, Head of NRL Imagers and Detectors Section said: “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.”
The benefits are not just for the Navy however. Solar cells that work underwater mean that research teams that work on the ocean floor can spend more time underwater while using less energy.
Via Discovery News