First Solar, Inc., the world’s largest producer of thin-film photovoltaics and one of the world’s largest PV manufacturers, is becoming a darling of investment analysts, a sign that solar is moving out of its ‘teenage’ stage and becoming a fully-fledged industry worthy of investment.

The company recently received a five-star stock rating from Morningstar, an investment research firm, and the company is among other investment analysts’ top picks for 2011.

Morningstar only gives the rating to 30 of the 1,700 companies it rates, according to The Street.

The news organization reported that “Morningstar speculates that First Solar is trading at a discount to fair value.”

Morningstar’s investment analyst Stephen Simko, who rates First Solar, did not respond to a request for comment by press time. Morningstar still recommends waiting for First Solar’s next sell-off to initiate a long-term position on its buy rating for the company.

Other analysts, like David O'Leary, who manages the PowerShares Active AlphaQ Fund, also are choosing First Solar as one of their top picks for 2011. Baron’s reported that His top picks for 2011 are First Solar and Research in Motion.

During its recent investor call, First Solar CEO Rob Gillette said, "We are benefiting from diversifying global partner demand and an increase in revenue from utility scale projects." Such projects include the 290 megawatt Agua Caliente Solar Project in Arizona which NRG Energy, Inc. agreed to purchase on Dec. 14, 2010.

Still, as the solar market heats up, there will be more competition.

“We always expect competition, but the global market for PV is expanding,” said First Solar Spokesperson Alan Bernheimer.

The company is projecting earnings between $8.75 to $9.50 per fully diluted share, and consolidated operating income is $875 to $975 million. And it expects to generate between $1.0 billion and $1.1 billion of operating cash flow in 2011.

To meet demands of the increased market, First Solar also increasing its manufacturing capacity.

“First Solar expects to manufacture nearly 2.2 GW of solar modules in 2011,” Bernheimer said.

The expanded production capacity and the increased market demand should allow the company to meet its earnings goals for the year.

Pictured: First Solar's Karlstadt-Laudenbach installation in Germany, courtesy of First Solar.