In a powerful signal that traditional energy companies are banking on solar power as part of their future, French oil giant Total plans to buy a controlling stake in San Jose-based SunPower (SPWRA), Silicon Valley's dominant solar panel manufacturer. Under the deal, jointly announced by the two companies Thursday as "a broad strategic relationship to shape the future of the solar industry," Total will buy a 60 percent stake in SunPower for $1.38 billion, paying a more than 40 percent premium over SunPower's stock price Wednesday. "This is old energy betting on new energy," SunPower CEO Tom Werner told this...