SunPower (SPWR -1.99%) has released another industry-leading product, the 21.5% efficient X-Series panel. This is another step ahead of the competition for SunPower and solidifies the company's lead against Chinese competitors and thin film maker First Solar (FSLR 1.33%). What does it mean for investors? The Motley Fool's Erin Miller sat down with Fool.com contributor Travis Hoium to find out.