U.S. Department of Energy

    Nanosolar to Build the World's Largest Solar Cell Plant

    June 28, 2006


    Photo of complex machinery featuring many metal rollers with a ribbon of metallic foil winding through them. The foil on the takeup reel has a dark tint because of the semiconductor coating.

    This desktop version of the Nanosolar process spools the metal foil off the reel in the bottom center; coats and heat-treats it; and winds the final product onto the reel on the lower right. The company also has a pilot plant that processes a
    12-inch-wide spool of foil.
    Credit: Nanosolar, Inc.

    Nanosolar, Inc. announced on June 21st that it will build a solar cell manufacturing facility that will eventually produce enough solar cells in one year to generate 430 megawatts (MW) of power. For comparison, worldwide solar cell production in 2004 was 1,109 MW, with only 138 MW in the United States, according to the International Energy Agency (IEA). Nanosolar plans to build the world-record-breaking manufacturing plant in the San Francisco Bay Area, and has started ordering volume production equipment for the facility. The company currently operates a pilot-scale facility in Palo Alto, California, and expects to achieve high production volumes through technology similar to the roll-to-roll printing presses employed by newspapers and other high-volume printers.

    Using nanotechnology, the company can spray a thin film of copper indium gallium diselenide (CIGS) onto an inexpensive foil, and the minute particles—on the scale of a billionth of a meter—will line up with each other, "self assembling" to form a layer of semiconductor. Such semiconductors form the heart of solar cells, allowing them to convert sunlight into electricity. The company uses a similar technology to add a transparent electrode layer on top of the semiconductor. According to Nanosolar, their planned manufacturing plant would cost $1 billion to build using conventional thin-film solar technologies, but will cost much less using roll-to-roll technology. To support the buildup to production, the company has raised $100 million through a combination of venture firms and a preferred stock offering. See the Nanosolar press releases (scroll down to see both press releases), the company's description of its "Seven Areas of Innovation," and the IEA statistics on worldwide solar cell production.

    While the Nanosolar news could be truly revolutionary for the solar power industry, recent history suggests that the news should be approached with caution. Back in 2000, First Solar burst onto the scene with a new factory that used glass coating technology to manufacture thin-film solar cells at high production rates, expecting to produce 100 MW per year. However, after commissioning the plant, the company determined that the actual plant capacity was much lower. In 2002, the plant produced only 1.5 MW of solar cells. Last year, the plant reached a production capacity of 21.5 MW, and is currently ramping up production, with a goal of producing 40 MW this year and 75 MW in 2007. See the January 3rd, 2001, edition of this newsletter and the First Solar press releases from 2003 (PDF 31 KB) and 2005 (PDF 76 KB). Download Adobe Reader.