Renewable Energy for Underwater Drones
Airbus, Boeing, and Softbank continue to develop solar-driven, glider-like stratospheric drones with virtually an unlimited range to survey earth and transmit data from 60,000 feet above the earth’s surface. Meanwhile, deep water drones are mining difficult to obtain information about earth’s single largest entity, its oceans (71% of the earth is covered by oceans, of which 95% is still unexplored).
We know more about space, at least near space, than we do about our deep oceans. Underwater drones, however, are now mining more essential data from sensors and visual instruments than ever before. The sensors measure ocean properties such as temperature, salinity, nitrate, oxygen, pH, and Chlorophyll, and can detect sounds from ship traffic, earthquakes, as well as wind and rain at the surface. Such data becomes critical as our oceans absorb more of the brunt of changes in our climate.
The drawbacks to underwater drones have been their cost to power and their environmental sustainability. Underwater drones must rely on battery power not the sun. When the batteries run out, the drones drop to the bottom of the ocean, since retrieval is usually more costly than the drones themselves. Below is a depiction of the number of dead drones at the sea bottom (in red) relative to the number still in operation (in green).
Now, however, a technology developed at the California Institute of Technology (Cal Tech) and the Jet Propulsion Laboratory (JPL) in Pasadena, California, and licensed by a small, start up company called Seatrec, headed by a former JPL scientist, Dr. Yi Chao, has created a renewable energy source to power underwater drones.
A portfolio company of the Los Angeles Cleantech Incubator, Seatrec harvests energy from the temperature differential in the ocean, essentially as much as the 18 degree Fahrenheit temperature change from the warmer water near the surface to the colder, deeper water. This thermal gradient within a power module attached to the drone converts solid material to a liquid, in the process creating mechanical energy to recharge the battery and increase the capability and life of the drone.
Funded by Breakout Labs, a member of the Thiel Foundation, and the Pasadena Angels, as well as with grants from the Schmidt Foundation and the federal government’s Small Business Innovation Research program, Seatrec has already started commercial sales of the solid-to-liquid powered modules and is developing under its own patent, a liquid to gas version, which will generate enough renewable energy to allow for a network of permanently tethered, underwater power stations so drones can stop by for a recharge. Turns out discoveries in deep oceans as well as deep space are now just beginning.
Gary V. Awad is a member of the Pasadena Angels and an Executive in Residence at the Los Angeles Cleantech Incubator.