Luminescent solar concentrators (LSCs) absorb and re-emit solar radiation into a waveguide coupled to efficient small-area photovoltaic cells. The cost efficiency of LSCs scales with collection area and increases with broader solar spectrum harvesting. Recently in Nature Photonics, Wu, Li, and Klimov demonstrate a tandem stack of two complementary LSCs of area > 230 cm(2) based on wavelength-separated colloidal quantum dots. A technoeconomic analysis demonstrates the promise of this approach for reducing the per watt cost of commercial photovoltaic systems.