y flows from the environment, through transformation and
distribution processes, and, ultimately, to final demand. Such energy
flow networks are called energy conversion chains (ECCs), and this
example is based on an approximation to a portion of the UK‚Äôs ECC circa
2000. (Note that these data are to be used for demonstration purposes
only and have been rounded to 1‚Äì2 significant digits.) These example
data first appeared in Figures 3 and 4 of Heun, Owen, and Brockway <span class="citation">(2018