If you tried to get an all-embracing view of energy use in the United States, it wouldn’t take long for your eyes to go blurry. The Energy Information Administration and other sources release reams of data almost constantly. That’s good if you want to look at minute detail, but not so good if you want the big picture.

Based on a version originally created by researcher David Bassett for the Woodrow Wilson Center, this energy flow map reveals the energy sources we draw from, the ways we use that energy, and the ways we waste it. Two elements are perhaps most striking: at bottom left, the relatively paltry contribution of renewables; and at far right, the staggering amount of energy lost as heat. On its own, this lost energy could satisfy the total demands of an industrialized nation like Japan or Germany.

Bassett created his first map of this kind in December 1990, while working in the pollution prevention division of the U.S. Environmental Protection Agency. When asked to update it to illuminate the current debate over energy policy, he jumped at the chance–but was dismayed when he compared the results with what he’d found two decades ago. “Aside from an increase in scale, they look much the same,” he said. “It’s sobering to realize how little we’ve been able to do to put this lost heat to use.”