Capturing the power of the sun
BISMARCK — What goes up may not necessarily have to come down if a Fargo firm successfully develops drones that would fly nonstop by harnessing solar rays and hot air and using power more efficiently.
Packet Digital LLC plans to collaborate with the U.S. Department of Defense and other partners to create a “solar soaring power management system” that would initially double the flying times of unmanned aerial vehicles, or UAVs, and ultimately give them unlimited endurance.
“It’s a very exciting project to be working on,” company President and CEO Terri Zimmerman said.
Continuously airborne drones could have applications for the military, agriculture sector, search-and-rescue crews and first responders, Zimmerman said. She believes there also could be interest among oil companies to use such drones to monitor pipelines.
In April, Google acquired drone manufacturer Titan Aerospace, which is developing a solar-powered, high-altitude drone that could stay airborne for five years and help provide Internet access in remote areas around the globe.
“I think that we’re only beginning to see the tip of the iceberg of what’s possible with UAS (unmanned aircraft systems), and I think this could provide many different types of applications,” Zimmerman said.
Most small, low-altitude commercial drones can fly for only 20 to 60 minutes at a time, though some military drones with larger wingspans and solar and soaring capabilities are able to stay aloft longer, Zimmerman said. Giving drones unlimited endurance will require not only better power management but also more advanced soaring and solar technology, she said.
Founded in 2003 and headquartered on the 15th floor of the Radisson Hotel in downtown Fargo, Packet Digital began developing power management integrated circuits about five years ago. The computer chips reduce power consumption and extend battery life in devices such as cellphones, laptops and servers.
So far, the Naval Research Lab has developed the most advanced solar cells, which are 33 percent efficient, according to Packet Digital. The company believes it can work with the lab to boost efficiency to 40 percent and develop “auto-soaring” algorithms that will take advantage of rising hot air, or solar uplift, to save on battery life.
Zimmerman said the company’s technology precisely matches the need for power to real-world conditions.
“So it never overpowers the system and it never wastes energy,” she said.
On Tuesday, the North Dakota Industrial Commission voted to schedule a special grant round for its Renewable Energy Program so that Packet Digital can submit its application for a $500,000 grant. If approved, it will allow the company to get started on the drone project with the Department of Defense and Naval Research Lab in September. The grant round closes July 18.
State lawmakers last year allocated $3 million to the Renewable Energy Fund for 2013-15. The money comes from the state’s Resources Trust Fund, which receives revenue from oil extraction tax collections and interest on loans made for certain regional water projects.
According to Packet Digital’s project description, the Naval Research Lab will provide high-efficiency solar arrays with durable film coatings to be mounted on the drone’s wings. ComDel Innovation of Wahpeton is the company’s partner for manufacturing and final assembly.
Packet Digital hopes to partner with North Dakota State University and/or the University of North Dakota for testing and analysis. Flight testing will take place at the Northern Plains UAS Test Site in Grand Forks, which in April became the first of six such test sites nationwide to be certified for operation by the Federal Aviation Administration.
Robert Becklund, executive director of the Northern Plains UAS Test Site, said the small drone currently being tested there can remain airborne for about 19 minutes, and the site soon will start testing a drone with a flight time of about 40 minutes.
“The ability to increase the endurance of the aircraft is going to be a good thing, and the stuff that Packet Digital is doing, that work is going to be really beneficial to the industry,” he said.
Of course, any discussion about solar power begs the question: What happens when the sun goes down?
Zimmerman said the highly efficient solar panels will provide excess power during the day to charge the drone’s batteries, and the power management system will allow that collected and stored energy to be used more effectively for longer flight times.