ROBOTICS AND AUTONOMOUS SYSTEMS
Solar Panels Could Increase Endurance for Robotic Systems
ATLANTA — By using solar cells along with traditional batteries, unmanned aerial vehicle manufacturers could triple or even quadruple a system’s endurance, said one industry executive May 6.
“We’re leveraging the power of the sun to keep the airplane in the air longer,” said Rich Kapusta, chief marketing officer and head of sales for Alta Devices, a company that produces solar cells.
“Think of us as the Red Bull for the small UAV industry, or the 10-hour energy drink.”
There are many promising domestic applications for small unmanned aerial vehicles, but their success will rely on increased endurance, he noted.
“Small UAVs are pretty popular for doing a lot of things, but they don’t fly for very long,” he said. Some systems have as little as 45 minutes to at most several hours of endurance.
One application that has been well publicized is using UAVs for precision agriculture. However, many of these farms can be thousands of acres wide, he said.
“If you have a big farm, you’re going to need to cover a lot of ground and take a lot of pictures. And today, if you can only fly for 20 minutes or an hour … you’re going to have to run a bunch of flights and stitch all that together,” he said. “If you had the ability to cover more ground, that could be extremely valuable.”
Pipeline and power line inspection applications would also benefit from increased endurance, Kapusta said.
Solar cells can vary in flexibility, weight and efficiency. Alta Devices’ solar panels use gallium-arsenide to increase its energy output.
“Gallium-arsenide has always been known to be a great solar material. It has been used in the space industry for decades,” he said.
The company’s solar cell panel has 28.8 percent efficiency. It also has a high power to weight ratio, he noted. It generates 1 watt of power per gram of mass. Because it is lightweight and flexible, it can easily be integrated onto the wing of an aircraft, he said.
The company is currently working with AeroVironment and testing its solar cells on the AE Puma. The last publicly disclosed demonstration was in 2013, but there is “ongoing” testing, he said.
“We’re working with AeroVironment to essentially get to the point where we can be on … the program of record,” he said. “We’re not quite there yet, but we’re taking steps along that path.”
During a test in 2013, Alta Devices and AeroVironment increased the Puma’s endurance from two to three hours to nine hours and 11 minutes, Kapusta said.
“We were really happy with that performance,” he said. “It just gives you an idea of the amount of endurance that you can get out all of these types of platforms.”
Most electric fixed-wing UAVs would benefit from being solar-assisted, he said. Along with increasing endurance, it would give the systems a reserve tank of fuel in case something went wrong.
The company is also looking to outfit its solar cells on other robotic systems, such as unmanned underwater submersibles. Additionally, the cells can be used on cars, manned aircraft and cellphones.
“Anything with a battery that can be exposed to some amount of light is a good opportunity for our solar cells,” he said.