Water
Cooling a dense rack is a water problem before it is an electricity problem.
The mechanism
Most large facilities reject heat by evaporating water. It is cheap, it is efficient, and it consumes the water permanently — evaporated water leaves the local system. A facility drawing on a municipal supply is drawing on the same supply as the town around it.
Why it reaches your invoice
Where water is contested, operators move to closed-loop or air cooling and absorb the efficiency penalty, or they site somewhere colder and absorb the latency and staffing cost. Either way the cost lands somewhere, and in a usage-priced contract it lands on you.
How we handle it
We run dense, efficient hardware at a scale where cooling is a design decision rather than a regional negotiation. When we plan capacity with an enterprise client, thermal and water strategy is part of the proposal, not a footnote discovered in year two.