Underwater Robot Powered By Ocean's Thermal Energy

separsons writes "A team of scientists recently created the world's first underwater robotic vehicle powered entirely by renewable ocean thermal energy. Researchers from NASA, the Scripps Institution of Oceanography and the US Navy developed Sounding Oceanographic Lagrangrian Observer Thermal RECharging (SOLO-TREC), an autonomous robot that runs on a thermal recharging engine. The engine derives power from the natural temperature differences found at varying ocean depths. SOLO-TREC produces about 1.7 watts of power each dive, enough to juice the robot's science instruments, GPS receiver, communication device, and buoyancy control pump. SOLO-TREC is poised to revolutionize ocean monitoring; previous robots could spend only a limited amount of time underwater because of depleting power sources. SOLO-TREC can stay beneath the surface of the waves for indefinite amounts of time. Based on SOLO-TREC's success, NASA and the US Navy plan to incorporate thermal recharging engines in next-generation submersibles."

Re:But can it steer?

[Anonymous Coward]

A steering AUV which is propelled under the ocean's thermal gradient is being developed by Teledyne Webb Research:
http://www.webbresearch.com/thermal.aspx

This has been around for a number of years so while the parent story is perhaps the first to be 'entirely' powered, the ocean has been powering such devices for years. The current model is 4th or 5th generation and is currently being flown in partnership with Rutgers University Institute of Marine and Coastal Sciences:
http://rucool.marine.rutgers.edu/
To track see the blog:
http://www.i-cool.org/?cat=75

For more information contact via the RUCOOL webpage or through Teledyne Webb Research's site.

Underwater robot powered by nature

[Anonymous Coward]

We did run this story on April 07, 2010 (link is here: http://www.global-adventures.us/2010/04/07/underwater-robot/). Temperatures at depth are not always easy to predict since they are influenced by many factors including ocean currents, light penetration (i.e. algae bloom). If it's made available, this technology will allow scientists to cover larger bodies of water, gain more data and over time a better understanding of whats going on in our Oceans.

Re:1.7 Watts of power each drive

[Iron Condor]

And how is this power produced. I'm going to guess what is happening is that it comes up and warms up till it's core temperature is at the ambient surface temperature. Then it drops like a rock, and uses the heat differential between the core and the cold water to drive some thermo electric engine in reverse. perhaps they toss in some phase change material to extend the thermal capacity.

or is it something different?

Why not ask the people who built it? From http://solo-trec.jpl.nasa.gov/SOLO-TREC/ [nasa.gov] :

Special Phase Change Materials (PCMs) on-board the SOLO-TREC expand about 13% when heated above 10 degree Celsius and then correspondingly contract when cooled below 10 degree Celsius. This expansion/contraction produces a high pressure oil that can be collected and periodically released to drive a hydraulic motor for electricity generation and battery recharging. Since its deployment, SOLO-TREC has been making 3~4 dives per day between the surface and 500 meters depth, producing about 1.6 Watt-hours of power each dive to operate the on-board sensors, GPS receiver and communication device.

I'd like to add that JPL is of course the place to go to if you need to run gizmos for a long time on almost-no-energy input, reliably, in rather hostile environments. I mean - the Voyagers are still sending data home, 30+ years later , 100+ AU away and with a transmitter not much better than a modern cell phone...