(Image source: empire-cat.com) Caterpillar Inc. (NYSE:CAT) was upgraded from neutral to buy by Bank of America Merrill Lynch on the growth potential of the company’s solar turbines and power systems. The bank believes that closes to 50 percent of Caterpillar’s operating earnings next year will come from power systems as a result of the slowdown in mining and construction. The price target was also increased from $87 a share to $100. Shares in Caterpillar are currently 2 percent higher on the upgrade.