"Green" Robot Self-Propels Through Sea

A seagoing glider that uses heat energy from the ocean to propel itself is the first "green" robot to explore the undersea environment, U.S. researchers said on Thursday.

They said the glider had crisscrossed the 13,000-feet-(4,000-meter-)deep Virgin Islands Basin between St. Thomas and St. Croix more than 20 times since it was launched in December.

And it could keep going on its own for another six months, the team at the Woods Hole Oceanographic Institution and Webb Research Corporation in Falmouth, Massachusetts, predicted.

Such robots can carry sensors to measure temperature, salinity and biological productivity.

Most gliders rely on battery-powered motors and mechanical pumps, the researchers said. This one draws its energy from the differences in temperature between warm surface waters and the colder, deeper layers of the ocean.

"We are tapping a virtually unlimited energy source for propulsion," Fratantoni said.

The more of these robots that are out there gathering data on our undersea world the better. If they can power themselves by the difference in temperature between warm and cold water indefinitely, we could have a whole army of these things that never need to return home for refueling. Not clear from the article how exactly the energy is generated, or how much energy it provides.

via Reuters via Engadget