Solar has officially gone corporate.

First Solar, the rapidly growing solar panel maker, has been placed on the S&P 500.

"First Solar is the first pure-play renewable energy company to be added to the index, which represents a milestone for the solar industry," First Solar said. "The company will be added to the S&P 500 GICS [Global Industry Classification Standard] Electrical Components & Equipment Sub-Industry of the Industrials sector."

Other companies that make renewable energy products like General Electric are already on the list, but it's an achievement nonetheless. The story of the company's rise is one of the great legends of the industry. Founded by in the mid-1980s by experts in tempered glass, First Solar struggled for years to move from the lab phase to broad-based commercialization. Except for John Walton, few investors supported the company. In the late '90s and early 2000s, it began to perfect the formula for cadmium telluride solar cells. Cad tel solar cells aren't nearly as efficient as crystalline silicon cells, but they can cost less to produce.

As sales climbed, First Solar filed for an IPO in November 2006. The stock went out at $20 and hit $200 within a year, a trajectory that compares with Google's first year. The economic calamity, among other factors, caused the stock to drop, but the company has consistently topped revenue and earnings expectations while dropping the average price of its solar panels. It broke the $1 per watt manufacturing cost barrier in 2008. During the second quarter, the cost per watt was down to 87 cents. But good luck figuring out how they do it – the company fiercely guards its secrets. First Solar is working on a way to bring copper indium gallium selenide (CIGS) cells to market.

Last month, it tapped Rob Gillette, who had been working as the CEO of Honeywell's $11 billion aerospace division, to become its new CEO.