Nanosolar Solar Cells

Nanosolar  has developed CIGS solar cells from copper indium gallium diselenide (CuInGaSe2). In this semiconductor material, the nanoparticles are inside a specially designed solar ink that is printed out on rolls made out of cheap aluminum foil (instead of glass substrate).

Nanosolar was established in 2002. After a quiet period of 7 years of development, they have started manufacturing nanosolar photovoltaic films in a small town near Berlin, Germany. Their factory is fully automated and uses the latest technology and equipment that enables producing one photovoltaic panel every ten seconds – a production which is an equivalent of 640 MW (megawatts) of power per year (provided that it runs without interruption 24 hours a day, 365 days a year). The company currently produces one million solar cells (about 1 MW of power) per month, including the production of their other line from San Jose, California. When you add up the production of both plants, Nanosolar could soon reach the capacity of their competitor – First Solar.

Nanosolar is a company which was founded with an initial capital of $ 150 million. Last year, they increased their value to $ 500 million before publicly revealing any details about their technology, business strategy or any kind of prediction regarding the capacity of production.

Breakthrough CIGS Technology

Nanosolar has developed a special printing of solar panels using a printing press technology, which has the potential of achieving huge savings in production. Nanosolar uses solar panels with a layer of only one micron of CIGS (copper-indium-gallium-selenide). The panels can be wired together to obtain larger high-performance panels, a feature we see today with some CIGS panels in a limited way. Instead of using glass as a substrate, they use aluminum foil. The advantages are several: first, the film is much cheaper (1-2 cents per mm of thickness). Second, the “roll-to-roll” technology enables printing films in rolls of 50,000 cells in a continuous fashion. Third, the end product is extremely lightweight and easy to use in numerous ways. The cells are hermetically sealed between two sheets of tempered glass, which makes the modules mechanically stronger, more durable and lighter than other thin-film modules so that they can be produced in larger sizes and reduce the need for cumbersome assembly aluminum frame. Nanosolar has not released the costs of production nor have they set prices, but the estimates go about $ 0.99 per Watt of power.

Nanosolar cells can convert up to 16.4% of solar energy into electricity. When the cells are connected to solar modules, the efficiency is about 11%. To compare, the traditional silicon modules have about 16% efficiency, whereas hybrid modules go up to 19.3% efficiency, but at much higher prices than thin-film modules.

Nanosolar panels can withstand 6-7 amps which allows the panels to be joined together into much longer lines before they can reach the limit of the inverter. This may reduce the need for cables used to connect to the inverter, and ultimately reduce a significant fraction of the cost of the system. Lastly, Nanosolar modules have an electrical connector at the edge of the module, rather than on the background so as to require only a short cable between the modules. This, in turn, reduces labor costs for connecting the modules.

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Tags: nanosolar CIGS, nanosolar solar cells, nanosolar technology