Wall Street is telling investors to buy coal and sell solar, Bloomberg reported.

Peabody Energy Corp., the biggest coal producer, is rated a “buy” by 79 percent of analysts, while 44 percent recommend First Solar Inc., the largest maker of thin-film solar panels.

The Stowe Global Coal index of 38 coal producers has gained 3.8 percent in 2010, and the Bloomberg Global Leaders Solar index of 38 solar module and component makers has dropped 17 percent.

Though investors including T. Boone Pickens and Warren Buffett are pushing cash into green technologies, the tilt toward Peabody and away from First Solar is the widest in two years, Bloomberg said.

Until government policies favor renewable energy over coal, “solar may seem too risky now for some investors,” said Kevin Landis, whose $260 million Firsthand Alternative Energy Fund includes SunPower Corp. and Suntech Power Holdings Co. “Coal may make sense short term.”

Solar companies’ profitability is falling because of competition from China and cuts to state support in Germany and Spain, where about 72 percent of power-producing photovoltaic panels were installed in 2008.

Peabody has rallied 9.8 percent since Feb. 12, when the benchmark coal price was $49 a ton, its lowest for 2010. First Solar was little changed. Coal is burned to make about 41 percent of power worldwide and will increase its share to 44 percent by 2030, according to the International Energy Agency.

The Stowe coal index has almost tripled its value in the past six months. That compares with a 15 percent loss for the Bloomberg solar index in the period.