 |
NRL's research will make true underwater solar submarines become a reality.
Because underwater water absorbs sunlight, underwater solar technology has proven to be very difficult. However, the United States Naval Laboratory (NRL) recently announced that its scientists have developed underwater solar cells capable of generating electricity at a depth of 9 meters to power electronic sensors.
Until now, the work of underwater electronic systems and sensor platforms has been severely limited by the energy supply and must rely on shore power, batteries, or solar power. Previously, Swiss researchers had successfully developed the world's first solar-powered manned submarine, allowing people to watch the underwater scenery in an environmentally friendly manner. However, the power source of the submarine is still the solar cell platform floating on the water surface. The NRL research will make real underwater solar submarines become a reality.
In the past, attempts at underwater solar cells have focused mainly on crystalline silicon cells. But in this study, NRL scientists abandoned crystalline silicon and switched to more efficient gallium indium phosphide (GaInP) batteries, which are ideal for underwater operations. GaInP cells have high quantum efficiency at wavelengths from 400 to 700 nanometers, and their inherent dark current is low, which is essential for high efficiency under low light conditions.
The reason why seawater is blue is because seawater absorbs the red part of the solar spectrum. The solar spectrum filtered by the bottom of the sea is biased towards the blue and green spectrum. It is also for this reason that there is currently no solar-powered submarine capable of working underwater. However, GaInP cells with high energy gaps mainly absorb those spectra that are not completely absorbed by water, that is, have efficient blue and green spectral absorption capabilities, and therefore perform better than conventional crystalline silicon cells.
Although underwater solar radiation is smaller, because of the narrower acceptable spectral range, once the solar cell can match the wavelength range, its battery energy will be greatly increased.
Preliminary results show that NRL can harvest 7 watts of solar power per square meter at a depth of approximately 9.1 meters. This is enough to prove that underwater solar cells in the offshore region are very promising.
Flanged Hex Bolts
Zhejiang XianChuang Auto Parts Co.,LTD , https://www.showstrong.com