Why: New types of photovoltaics are reducing the cost of solar power.

Key innovation: "Thin-film" solar panels based on cadmium telluride, which are cheaper than conventional silicon panels, have made the company one of the world's largest photovoltaic manufacturers.

Technology:

The leading producer of thin-film solar panels, First Solar has established an alternative to conventional silicon-­based technology. The key is a material called cadmium telluride, which absorbs light better than silicon does; as a result, extremely thin films of the material are all that’s needed.

Market:

The Arizona-based company is among the top three suppliers of solar panels in the world, with customers in all major markets. In response to strong demand, it has doubled production capacity at its factory in Germany and begun construction of a facility in Vietnam. The company says it plans to build a second facility in the United States.

Strategy:

First Solar’s priority has been to drive down manufacturing costs; in 2008 it broke the all-important $1-per-watt barrier, and it’s since brought the figure down to 75 cents per watt. After years of work to increase the efficiency of its cells, it may now be approaching the physical limits of cadmium telluride. Reports have suggested that the company's R&D team is exploring the possibility of making thin-film panels from copper indium gallium diselenide, a material with greater potential for efficiency improvements.

Challenges and Next Steps:

First Solar faces stiff competition from Chinese manufacturers that are driving down the cost per watt of silicon panels, and its status as the only major producer of thin-film cadmium telluride panels may soon be at an end: General Electric is expected to introduce its own this year.