Elon Musk's SolarCity has the world's most efficient solar panels
 

SolarCity, the company co-founded by Elon Musk, now produces the world's most efficient rooftop solar panels with a module efficiency of just over 22 percent. That bests the X-Series panels built by SunPower, which top out at around 21.5 percent. T...

http://www.engadget.com/2015/10/02/e...op-efficiency/