Ultra-lightweight CIGS solar module for high altitude airship applications

U.S.-based CIGS thin film module manufacturer, Ascent Solar, has recently developed a 25 W laminated PV module that can be used in large unmanned aerial vehicles (UAVs), high-altitude lighter-than-air (LTA) vehicles, and fixed-wing aircraft.

The new product, dubbed HL 25 HyperLight, has been designed as a modular power system component with a size of 919 x 316 x 0.26 mm and a weight of just 82 grams, including a bypass diode within the package that protects each of the two series strings. A small 300 W array made of these panels would weigh in at around 1 kg.

The nominal voltage of the panel is 40 V and the current at maximum power is 0.7 A. The short-circuit current is 0.8 A and the open-circuit voltage 52 V. Its power conversion efficiency is 11%, with near-term efficiency improvement plans in the works, according to the manufacturer. “The potential for CIGS to be used in conjunction with new tandem/hybrid devices including perovskite, and as a mechanism for facilitating novel technologies such as wireless power-beaming, makes it the ideal platform for sustained PV technology innovations,” said Ascent Solar.

The modules, according to the manufacturer, can be connected with traditional aerospace methods such as spot welding and soldering, and each include a bypass diode covering each 20 V string in the laminate to facilitate easier integration.

The manufacturer uses a roll-to-roll manufacturing process that is said to be capable of high-speed production leveraging a 25 inch polyimide substrate, which is then combined with Ascent's patented monolithic-integration patterning process. “This process provides our customers with the lightest, most flexible, highly-rugged PV material able to withstand the harshest environments, such as bullet-holes, micro-meteorites, and harsh temperature and radiation situations,” a company spokesperson told pv magazine.

The panel is designed to operate at air mass zero (AM0), which is the standard spectrum outside the Earth's atmosphere. For example, in May Ascent Solar announced a module order from an unspecified customer that is developing an unmanned, helium-filled airship operating in the stratosphere at an altitude greater than 60,000 feet above sea level.

According to the company, the light weight of the module is highly advantageous in the space and aerospace sectors, as mass constitutes one of the biggest launch costs and payload mass limiters in space flight planning today. “The 300+ W/kg specific power will allow for increased flight-planning and operational resilience, while also accommodating the typical hazards of launch and space-environment scenarios, providing for optimal overall operational efficiency,” continued the spokesperson.

Ascent Solar is based in Denver, Colorado, United States. “Our manufacturing capacity is being planned to accommodate needs in our focus sectors projected to increase into the hundreds of megawatts over the next 5 years,” the spokesperson concluded.