In another solar energy deal, Gibraltar Industries (Nasdaq: ROCK) is buying RBI Solar Inc. and Rough Brothers Manufacturing Inc. for $130 million.

Cincinnati-based RBI and Rough Brothers operate the largest greenhouse manufacturer in North America, and also provide solar panel racking services, which is part of the installation process. The global market for photovoltaic racking is $9.3 billion, and is forecasted to grow at a 14 percent rate over the next four years. Of RBI's $164 million in revenues for 2014, two third were from solar racking sales.

Gibraltar, headquartered in Buffalo, New York, manufactures building products for the industrial, infrastructure and residential markets.

Other deals related to renewable energy have come from SunEdison Inc. (NYSE: SUNE), which bought seven wind, hydro and solar projects in May; and from Solar Power Inc., which picked up energy project operators in November.

Energy industry