(click to enlarge)
This grid collects the coal in the repositories that accompany 240 different coal-burning power plants around the world. The pushing, piling up of, and tracks through the coal attest to its irreducible materiality -- this is the stuff that in many places must be burned in order to keep things going. It's used up, replaced, and used up again.
Differing colors reflect the quality of satellite imagery in that country (for instance, China tends to be blue or purple-ish, while coal in the US appears a flat black or slightly greenish). This difference is ironic at best, since coal is coal regardless of where it is burned.