Energy — Know

How does the conservation of energy apply to more complex, multi-stage energy transfers such as Sankey diagrams?

Even across several stages of transfer, the total energy input still equals the total energy output (useful plus wasted) at every stage, since energy cannot be created or destroyed. A Sankey diagram shows this using arrows whose width is proportional to the amount of energy, splitting at each stage into useful and wasted (usually heat) pathways, with the combined width remaining constant throughout.