Despite a respectable fourth quarter for First Solar (FSLR 0.05%), with normalized earnings per share beating estimates by $0.31, the stock sunk 15%. So what was the bad news? In this video, Motley Fool energy analyst Joel South tells us that increased competition from companies that are creating more efficient solar panels, and also competing on cost, are threatening First Solar's dominance in the industry. Margins continue to be pinched, and with project backlogs declining, the future looks rocky.