Watt is Joule/second

3 gigajoule per second. It already has a unit of time.

3GW/9GW is peak load, as I understand it - data centres usually operate at 85-90% of peak load according to Goldman Sachs.

Meanwhile, the 4GW figure is average demand - Utah consumed 35,075GWh for 2025, so average demand of 4GW (35075/(365*24)).

3GWh/h.