Energy is consumed by every sector of the U.S. economy. The official “accountant” of energy production and consumption in the U.S. is the U.S. Energy Information Administration (EIA). It distinguishes between transportation (ground, air and water), industry (small and large producers, agriculture and mining), and buildings (homes, office buildings, hospitals, etc.). Of these three sectors—transportation, industry, and buildings—which consume the most energy in the U.S.? This simple question should be easy to answer, but the answer depends on what is meant by “energy consumption.”