SunPower (NASDAQ:SPWR) has long held a lead in panel efficiency, the major competitive advantage it has in solar. But how durable is this competitive advantage with everyone trying to pump out more power per square inch? 

Trina Solar (NYSE:TSL) recently announced a lab cell that reached 24.4% efficient, on par with SunPower, and equipment supply companies are trying to increase efficiency for all manufacturers. Even First Solar (NASDAQ:FSLR) says it will increase efficiency to 19.5% by 2017. 

The fact of the matter is that SunPower's 21.5% efficient panels are well above the 15% to 17% that is standard in the industry and for those modules to make a significant leap they'll have to improve processes, like making back contact panels like the Trina cell mentioned above. But most manufacturers don't do that process, giving SunPower a head start. 

It's one thing making an efficient panel in a lab and another making it commercially viable, which SunPower has already done. Solar specialist Travis Hoium covers this and more in the video below. 

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Travis Hoium manages an account that owns shares of SunPower and personally owns shares and is long SunPower options. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.