Stacking Cells Could Make Solar as Cheap as Natural Gas

When experts talk about future solar cells, they usually bring up exotic materials and physical phenomena.  In the short term, however, a much simpler approach, stacking different semiconducting materials that collect different frequencies of light, could provide nearly as much of an increase in efficiency as any radical new design.  And a new manufacturing technique could soon make this approach practical.

The startup Semprius, based in Durham, North Carolina, says it can produce very efficient stacked solar cells quickly and cheaply, opening the door to efficiencies as high as 50 percent.  (Conventional solar cells convert less than 25 percent of the energy in sunlight into electricity.)

Semprius has come up with three key innovations:  a cheap, fast way to stack cells, a proprietary way to electrically connect cells, and a new kind of glue for holding the cells together.  In its designs, Semprius uses tiny individual solar cells, each just a millimeter across.  That reduces costs for cooling and also helps improve efficiency.

Stacking Cells Could Make Solar as Cheap as Natural Gas