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Ascent Solar Develops Opportunities in Thin-Film CIGS Field

By David Savastano

The field of thin-film photovoltaics (PV) is extremely promising, as interest in finding ways to utilize solar energy continues to grow.

In particular, the fields of specialty market products that include electronic integrated PV (EIPV), Defense, commercial transportation integrated PV (TIPV) and building integrated PV (BIPV) are seen as strong opportunities for thin-film products, which are by nature light weight, flexible and can be less expensive to produce that rigid solar systems. As a result, thin film can be used in places where a glass panel would not succeed, whether it is for displays, for tents or for individual buildings.

For Ascent Solar Technologies, Inc., Thornton, CO, thin-film PV is the ideal market. The company utilizes copper indium gallium diselenide (CIGS) technology for its modules, and has drawn much interest from a wide variety of customers, most notably the military, automotive and construction industries. By manufacturing PV modules out of polyimide, Ascent Solar is able to lower overall system costs while providing the greatest power density.

In 2009, the company opened its 1.5 MW production line (FAB1), and commenced commercial production at its new FAB 2 production facility in Thornton, CO, this year. FAB2 will ramp up its annual rated production capacity through the rest of this year and expects to produce 6-8 MW by the end of 2010.

Ascent Solar is the creation of Dr. Mohan Misra, founder, president and CEO of ITN Energy Systems, who has begun quite a few successful companies along the way, including Global Solar, a thin-film PV specialist that utilizes flexible stainless steel substrates.

“Dr. Misra started at Martin Marietta, and had specialized in thin film solar cells for satellites,” said Brian Blackman, Ascent Solar’s director, investor relations. “He determined that roll-to-roll production of CIGS solar cells was the way to go. He formed Global Solar in Arizona, and after that, moved back to Littleton, CO, where he worked on utilizing polyimide substrates to create complete modules. From 2000 to 2005, Dr. Misra and his team focused on R&D, and incorporated Ascent Solar in 2005.”

“For us, the key differentiator is that roll-to-roll allows us to produce material at the lowest possible cost,” said Dr. Farhad Moghadam, president and CEO of Ascent Solar. “In addition, polyimide is competitive with the cost of glass or any other substrate, and there is no limit to the length of the roll. It is lightweight, so the logistics cost is lower.”

Ascent Solar uses a laser to cut into the surface of the substrate, and fills into the trenches with an insulating ink. Dr. Moghadam said that by using polyimide, Ascent Solar can do cell-to-cell isolation with excellent efficiency, which is critical.

“We use a one-third meter web, and while our building blocks are typically 12 by 6 inches, we can produce modules up to 5 meters long,” Blackman added.

Specialty markets are the company’s primary focus, like Defense, Electronic Integrated PV (EIPV) and Transportation Integrated PV (TIPV).

“Flexible and lightweight with a high power to weight ratio, is the real advantage we have when talking about the specialty market segment of PV,” Dr. Moghadam said. “Amorphous silicon technology can typically produce 6 to 8 percent efficiency; we’re producing 11 to 12 percent efficiency, with our modules ranging up to two meters. We can process 300 to 600 meter rolls of polyimide, and we produce to customer specifications. For example we can produce a portable module the size of your credit card or up to two meters long.”

In a key specialty market move, Ascent Solar recently announced a strategic alliance agreement with Kirloskar Integrated Technologies Limited of India.

“In India, glass PV has been a big issue with theft and breakage. Kirloskar was looking for a rugged product that can be easily taken in at night after usage,” Dr. Moghadam said.

Dr. Moghadam noted that thin-film PV is ideal for a wide array of specialty market products, where conventional glass panels are problematic. Ascent Solar's modules can provide a light weight, durable and customizable solution.

“Another important specialty market for Ascent is commercial transportation where unit weight is essential, transportation roof tops such as a truck’s trailer can’t take on glass modules for a number of reasons,” Dr. Moghadam said. “With the emergence of commercial hybrid electric transportation we see a tremendous opportunity to meet the demand for populating the roof space with 1 to 5 kilowatts of our material to enhance the mileage of the product. We have seen a lot of interest from the transportation sector.”

“For BIPV we are working on glass facades on high-rise buildings, in which the system is laminated between two layers of glass, as well as extruded aluminum shades that go over windows, and integration into standard building products” Dr. Moghadam added.

Dr. Moghadam noted that the efficiencies that Ascent Solar reports are production quality, not pilot production size, which bodes very well for the company’s future growth.

“When it comes to quoting efficiency,” Dr. Moghadam noted. “ We are talking about real products produced commercially.”