Trina Solar will begin to sell modules in the U.S., Australia and Europe that are grooved to accommodate the low-cost racking system invented by Zep Solar -- one more tiny step in reducing the cost of solar.

Racking may not be the most glamorous end of the solar business, but balance-of-system costs like this can still account for one-third or more of the cost of a residential or commercial rooftop system. Schletter, which has been around for decades, has a 30 percent share of the European market, while Unirac is a major fact of life in the U.S. Still, a few startups have emerged in recent years. Lumeta, for instance, unveiled a stick-on solar panel at Solar Panel International this past October that eliminates traditional racking entirely.

Instead of mounting solar panels on the traditional metal frames used now, Zep props up the panels through interlocking rails and components. In layman's terms, the Interlock is essentially a leg that clamps onto the frame of a solar panel and serves to prop up the solar panel and fasten it to the other panels in the array. Instead of a table, you just buy the leg. The structure of the panel becomes part of the rack. Overall, Zep says it can cut the time contractors spend on a roof by 75 percent. It also makes wiring easier.

The key is that the system requires modules with a specially grooved frame. (Side note: Zep did not name itself in tribute to Led Zeppelin. All the good names were taken, a company spokesperson told me.) Zep landed Canadian Solar as a customer approximately a year ago.

Trina is one of the largest solar makers in the world, but it is unclear how extensively the company will adopt Zep's technology.