Illustration: Javier Palma
Feb 4th 2026|Boulder, Colorado, and Cambridge, Massachusetts|6 min read
BY ANY REASONABLE measure, Michael McGehee’s laboratory at the University of Colorado in Boulder looks like a good investment. With a four-year $8m grant from the Department of Energy (DoE)—a rounding error in the agency’s almost $50bn budget—a small team of scientists has been refining a technology that could transform the economics of renewable energy. Tandem solar cells, formed by topping a layer of silicon with a special crystal known as a perovskite, have an efficiency well beyond that of conventional panels.