The cost of producing a conventional crystalline silicon (c-si) solar panel continues to drop. Between 2009 and 2012, leading "best-in-class" Chinese c-Si solar manufacturers reduced module costs by more than 50 percent. And in the next three years, those players -- companies like Jinko, Yingli, Trina and Renesola -- are on a path to lower costs by another 30 percent.

Check out this chart outlining projected costs, which comes from GTM Research's Global Intelligence PV Tracker:

"Clearly, the magnitude of cost reductions will be less than in previous years. But we still do see potential for significant cost reductions. Going from 53 cents to 42 cents is noteworthy," says Shayle Kann, vice president of research at GTM Research.

With plenty of innovation still occurring in crystalline silicon PV manufacturing -- including new sawing techniques, thinner wafers, conductive adhesives, and frameless modules -- companies are able to squeeze more pennies off the cost of each panel. However, as the chart above shows, innovating "outside the module" to reduce the installed cost of solar will be increasingly important as companies find it harder to realize cost reductions in manufacturing.