Here is the MIT report.
With solar panel prices falling more than 80 percent in the last few years, many solar companies are turning their attention to reducing the cost of installing them. Two leading solar companies, Solon Energy, based in Berlin, and Trina Solar, based in Changzhou, China, have announced new designs for mounting solar panels to roofs—the companies say these designs can reduce the installation time by more than half, greatly reducing labor costs. The new designs reduce or eliminate the tools and hardware needed to install solar panels, and standardize solar installations, which have largely been ad hoc, reducing the time needed to design them.
While solar panels themselves used to account for most of the cost of large solar installations on commercial rooftops, the modules now account for about 40 percent of the cost. The rest comes from things like the necessary hardware, power electronics, and labor—which alone accounts for about 30 percent of the total.
Mounting solar panels on the flat rooftops of commercial installations typically involves anchoring long metal racks to the roof to create a framework that will angle the panels toward the sun and hold them together. Installers bolt the panels to this frame, wire the panels together, and electrically ground the racks.
Go there and read. More tomorrow.