Solar film manufacturer explains potential for UAS market

By Luke Geiver | October 29, 2015

Alta Devices, a California-based solar film developer, has indexed the options and issues related to solar power used on unmanned aircraft systems. “There are over twenty photovoltaic technologies actively pursued by various manufacturers and research groups,” the company said in its whitepaper on the topic titled “Solar for UAV Index.”

“Traditionally the industry has only looked at efficiency when comparing and selecting solar technologies,” said Tanya Wilkins, business development director for Alta Devices. “In actuality, the uniqueness of UAVs elevates other factors for consideration such as power to area and packing density,” adding that “the new index permits customers to see a more complete picture of how different solar technologies compare in the context of UAVs.”

In addition to the weight and surface area availability variables considered before including solar power on a UAV, Wilkins said other challenges exist. “The solar cells must also pass extensive stress and environmental testing. Significant stresses are placed on the solar cells due to the bending of the aircraft wing in flight,” Wilkins said. Environmental damage can occur from flight at high altitudes due to high levels of ultraviolet (UV) radiation and extreme temperatures, she also said.

While solar presents challenges to certain platform designs, it can extend flight duration and range by as much as three to four times over batteries alone. According to Wilkins, the best applications for solar-equip UAVs include border patrol, disaster management, internet delivery, search and rescue, precision agriculture and infrastructure monitoring.

Alta Device’s whitepaper outlines a number of considerations for selecting a solar option addition to a UAS, including: power to weight ratio, power to area ratio, ease of integration, durability and reliability. There are two basic forms of solar options, wafer-based and thin-film types. According to Alta, the vast majority of existing solar cells and manufacturing capacity is of crystalline silicon, typically made of six-inch wafers. The technology offers an energy transfer efficiency of roughly 17 to 20 percent. The wafers must be housed in thick laminates for adequate protection.

Alta Devices manufacturers thin solar films for use on cell phones, portable power devices and now the UAS industry. The company has seen strong demand from UAV companies located throughout the world. The product made by Alta Devices features a 25 to 35 percent efficiency.

The new index replaces other basic mathematical formulas and instead puts a premium on simultaneous minimization of weight and surface area. Alta is currently working with AeroVironment to integrate solar into certain platforms.

To view the index, click here: 

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