Feeds

US Navy uncloaks stealthy underwater solar cells

Energy capture up to nine meters down

High performance access to file storage

Scientists at the US Navy Research Laboratory (NRL) are developing solar cells that can work effectively up to nine meters underwater, powering marine systems for long periods of time.

Big data is not just for the boardroom, but for the battlefield as well, and military planners are working on using a lot more stealthy sensors and systems that need power without carrying batteries or sticking a solar panel out of the water. But light isn't very effective at penetrating seawater, and conventional solar cells that rely on silicon aren't very good at catching what little light that does.

"The use of autonomous systems to provide situational awareness and long-term environment monitoring underwater is increasing," said Phillip Jenkins, head of NRL Imagers and Detectors section, in a statement. "Although water absorbs sunlight, the technical challenge is to develop a solar cell that can efficiently convert these underwater photons to electricity."

While the amount of light penetrating seawater falls off rapidly with depth, what little that does get down is in a fairly narrow spectral band. The scientists focused on this area using gallium indium phosphide (GaInP) solar cells, similar to those used by satellites, which are highly efficient in visible-light wavelengths, and perform far better than run-of-the-mill photovoltaics in the blue/green portion of the spectrum predominant in seawater.

US Navy solar cell performance underwater

New cells focus on what little light you can get in the vasty deep

The team now estimates that a square meter of these cells would generate 7W of power at 9.1 meters of depth, with better performance – of course – at shallower depths. The team suggests they'd be most effective in coastal regions on low-power applications to replace monitoring stations using fixed power lines. ®

High performance access to file storage

More from The Register

next story
Fancy joining Reg hack on quid-a-day challenge?
Recruiting now for charity starvation diet
Red-faced LOHAN team 'fesses up in blown SPEARS fuse fiasco
Standing in the corner, big pointy 'D' hats
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
Opportunity selfie: Martian winds have given the spunky ol' rover a spring cleaning
Power levels up 70 per cent as the rover keeps on truckin'
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
New FEMTO-MOON sighted BIRTHING from Saturn's RING
Icy 'Peggy' looks to be leaving the outer rings
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.