Nanosolar - Technology

Technology

The company uses copper indium gallium diselenide—which achieves up to 19.9% efficiency in laboratory samples—to build their thin film solar cells. The company's technology gained early industry recognition with the presentation of a Small Times Magazine award at a leading nanotech business event in 2005. Technical details of Nanosolar's manufacturing techniques have been disclosed in patent applications. Some information about their process has become available in a Scientific American article (in German). These details involve a semiconductor ink that it claims will enable it to produce solar cells with a basic printing process, rather than using slow and expensive high-vacuum based thin-film deposition processes. The ink is deposited on a flexible substrate (the “paper”), and then nanocomponents in the ink align themselves properly via molecular self-assembly.

Nanosolar's solar cells have been verified by NREL to be as efficient as 14.6% in 2006, 15.3% in 2009, and 17.1% in 2011. Efficiencies for current production panels are said to be 8-9%, with plans to submit panels with 10-11% efficiency for IEC certification in the fall of 2010.

In September 2009, Nanosolar announced the launch of production at a rate of 640 MW annually; however, ramp-up to volume production after the announcement took an additional six months, limiting actual production in 2009 to an estimated 4 MW, and as of August 2010 the plant is still ramping up toward its announced capacity. Since the hiring of new CEO Geoff Tate, the company has declined to discuss its actual manufacturing capacity, but has said that its target for 2010 is to ship panels for "several ... megawatt-size projects" and " panels for projects that have been identified that can help build the case for an operating history and bankability in 2011."

Nanosolar has developed a suite of in-house capabilities for creating nanostructured components based on various patented and patent-pending techniques. It uses nanostructured components as the basis for creating printable semiconductors, printable transparent electrodes, novel forms of advanced nanocomposite solar-cell design and powerful new forms of barrier films.

According to the company, "leveraging recent science advances in nanostructured materials, Nanosolar has developed a proprietary ink that makes it possible to simply print the semiconductor of a high-performance solar cell. This ink is based on Nanosolar developing various proprietary forms of nanoparticles and associated organic dispersion chemistry and processing techniques suitable for delivering a semiconductor of high electronic quality."

Two advantages over earlier technologies is that a printing process is quick and also makes it easy to deposit a uniform layer of the ink, resulting in a layer with the correct ratio of elements everywhere on the substrate. Also, the ink is printed only where needed, so there is less waste of material. Last, the substrate material on which the ink is printed is much more conductive and less expensive than the stainless steel substrates that are often used in thin-film solar panels.

These solar cells successfully blend the needs for efficiency, low cost, and longevity and will be easy to install due to their flexibility and light weight. Estimates by Nanosolar of the cost of these cells fall roughly between 1/10 and 1/5 the industry standard per kilowatt. However, solar module prices have fallen by 60% since that prediction in 2006.

The company implies that their solar cells can last more than 25 years by saying they "achieve a durability compatible with our 25-year warranty." They recently commissioned a study by Black and Veatch that finds their 25-year warranty to be compatible with their module design.