Feeds

US Navy uncloaks stealthy underwater solar cells

Energy capture up to nine meters down

Application security programs and practises

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. ®

Build a business case: developing custom apps

More from The Register

next story
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
BEST BATTERY EVER: All lithium, all the time, plus a dash of carbon nano-stuff
We have found the Holy Grail (of batteries) - boffins
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
Bad back? Show some spine and stop popping paracetamol
Study finds common pain-killer doesn't reduce pain or shorten recovery
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.