Global Solar Energy, a maker of thin-filmsolarcells, has proven to be its own best customer.

The first commercial solar energy system using Global Solar's copper indium gallium diselenide (CIGS) cells is now working to power none other than Global Solar's own 40-megawatt factory in Tucson, Ariz.

Solon Corp. in Germany made the solar panels containing the CIGS cells. It also designed the 750-kilowatt system, which is made up of 6,600 panels spread over 310,000 square feet of space on the ground.

Solon, which also makes cyrstalline siliocn panels, began exploring the thin-film market about three years ago, said Lars Podlowski, chief technical officer of Solon, at a Photon International conference in San Francisco Wednesday. The company bought a 19 percent stake in Global Solar in 2006.

The energy system Global Solar has installed will feed 25 percent of the factory's power needs.

Global Solar doesn't have to pay for the system though. MMA Renewable Ventures put up the undisclosed cost of installing the system. MMA, based in Baltimore, Md., owns and operates the system and sells the electricity to Global Solar through a long-term contract.

MMA also will recoup some of the cost by selling the renewable energy credits from the project to utility Tucson Electric Power.

The solar energy system is the not just the first for Global Solar, but the largest commercial CIGS system in the market, the company said.

Other CIGS makers, such as Fremont, Calif.-based Solyndra, have erected smaller, but still multiple-kilowatt, demonstration plants.

Whether a CIGS manufacturer setting up a system for its own use is commercial remains to be a judgment call. Still, the size of the deployment buoys optimism that CIGS mass manufacturing is on the way.

CIGS is one of the thin-film technologies being developed by companies hankering for a slice of the growing solar market. The vast majority of solar panels sold today use crystalline silicon as their key sunlight-converting ingredient. Many believe CIGS solar panels will be more efficient and more economical than thin-film cells made with cadmium telluride or amorphous silicon.

Few CIGS companies, however, are actually making products and even fewer are shipping in anything a reasonable person might call high volumes. CIGS is not easy to work with.

Solyndra began shipping its panels in July and has announced $1.52 billion worth of sales contracts (see Solyndra Rolls Out Tube-Shaped Thin Film and Solyndra Snags $320M Deal with Roofing Firm). Those sales contracts allow Solyndra to deliver that $1.52 billion worth of solar panels over the next four to five years.

In Dec. 2007, Nanosolar announced it had begun producing CIGS panels. Those panels were heading to Beck Energy for a 1-megawatt project in Germany. (see Nanosolar Begins Production). How many panels Nansolar has delivered remains a mystery and a major subject of debate in Silicon Valley.

Nanosolar also is developing a second power plant in Germany (see Nansolar to Build a 10MW Power Plant).

Global Solar sets itself apart from other CIGS players by only producing cells, which are assembled into panels by customers (see Global Solar Strings Thin-Film Market Together and Global Solar Sells Out Year's Production).

The company celebrated the opening of a 35-megawatt factory in Germany last month.

In July, the company said it was on track to reach full production at its 40-megawatt factory. The plant was running at a rate between 5 megawatts to 10 megawatts at the time. 

The company isn't reaching that goal, however. During his talk, Podlowski said the company aims to reach the production capacity of 25 megawatts next year and make cells at $2.50 per watt.

Reporter Jeff St. John contributed to this story.