Electronics

Special solar cells produce electricity from underwater sunlight

Special solar cells produce el...
Scientists have successfully used gallium indium phosphide solar cells to generate electricity underwater (Photo via Shutterstock)
Scientists have successfully used gallium indium phosphide solar cells to generate electricity underwater (Photo via Shutterstock)
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Scientists have successfully used gallium indium phosphide solar cells to generate electricity underwater (Photo via Shutterstock)
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Scientists have successfully used gallium indium phosphide solar cells to generate electricity underwater (Photo via Shutterstock)

Although solar cells are proving indispensable for powering things such as electronic sensors on dry land, sensors located underwater have typically had to rely on batteries, or electricity piped in from photovoltaic panels situated above the surface. That could be changing, however, as scientists from the U.S. Naval Research Laboratory have recently developed functioning underwater solar cells.

Water absorbs much of the spectrum of sunlight – blue-green light is the last portion of the spectrum to be absorbed, and thus penetrates the farthest below the surface. Because traditional topside silicon solar cells are designed around the full solar spectrum, this leaves them little to work with when placed underwater.

It turns out, however, that gallium indium phosphide (GaInP) cells are highly efficient at converting light within the less intense blue-green wavelength into electricity. When used at depth underwater, GaInP cells receive nothing but the wavelength that they are optimized for, allowing them to perform much better than regular silicon cells under the same conditions.

So far, it has been determined that GaInP cells placed at a maximum depth of 9.1 meters (29.9 feet) provide an output of 7 watts per square meter (10.8 sq ft) – enough to power a device such as an environmental sensor.

Source: U.S. Naval Research Laboratory

7 comments
Paul Robertson
urban water catchments are going to be an indispensable source of open area for the easy placement of pv electricity generation. this begins to open up the possibility of these systems being under the water.
Slowburn
Mounting your solar cells under a couple feet of water would protect them from hail storms.
Stewart Mitchell
This article implies that it is not for commercial electric generation. Only for small scientific power supplies.
yourmomthinksimcool
Hail would no longer be a problem but algae and other encrusting organisms certainly would be. If you have ever had an aquarium you know it doesn't take long to get covered in algae.
Slowburn
re; yourmomthinksimcool
There are ways of controlling algae growth. The question is one of economics, is it more cost effective to pay for insurance and lost productivity, or to pay for the algae control.
DIOMOID
I wonder if the shadows (resulting from the crest of the waves?) would limit the efficiency of these solar cells. Hmmn, could the difference between the shady and non-shady parts be utilized? Im no expert in electrical stuff, but it seems as if the moving action of the waves could also help generate and/or move the flow of electricity?
Diana Hockley
An to think Australia is still digging up coal :( Our country is one of the hottest, oodles of sun and the political idiots are allowing a rich idiot to open a huge cola mine in Central Queensland.
WHAT ARE THEY THINKING OF?
China, who is Australia's largest buyer of coal, is going solar as much as they can and building huge solar plants for the future! What then for Australia's coal industry?
The Holden car manufacturing plant in Adelaide is closing in a couple of years throwing thousands out of work, so why can't the aforesaid idiot throw his billions into solar technology and use some of the workers from there, if not right no, then later?
No no, coal is too easy!!! Heaven protect us from these idiots.