Fixed capital stock functions as an embodied energy storage system that connects economic activities which do not happen simultaneously. This paper constructs a dynamic energy input-output model to analyze embodied energy flows and stocks along both temporal and spatial dimensions from 2000 to 2014. The results show that 2043 exajoule of embodied energy was stored in the global fixed capital stock in 2014, which was about three times the world's direct energy use. Compared with those in developed countries, the gaps between the dynamic energy footprints and the traditional ones were larger in fast-developing countries. Net embodied energy usually flowed from high-intensity economies to lower-intensity economies, and around 10% of the energy embodied in trade came from depreciation. The dynamic embodied energy indicators provide information for improving energy efficiency and mitigating corresponding problems from the perspective of consumption.
Keywords: capital; embodied energy; energy footprint; energy input−output model; energy storage; investment.