Explainer: the water-energy nexus, without the jargon

Every unit of water moved, treated or desalinated costs energy. Every unit of thermal or hydro generation costs water. Planning them in separate ministries produces plans that are individually coherent and jointly impossible.

The practical test is simple: does the national water plan's projected pumping and desalination load appear in the national energy demand forecast? In most cases examined, it does not.1

Renewable-powered desalination changes the arithmetic but not the requirement. Intermittent supply means storage or flexible operation, and flexible desalination plants are designed differently from baseload ones — a decision that must be made at feasibility stage, not retrofitted.