What is being calculated?
Annual facility energy (kWh) = installed IT capacity (kW) × average electrical load factor × 8,760 hours × annual PUE.
Annual energy charge (USD) = annual facility energy × assumed energy rate (USD/kWh).
The example uses a non-leap year and a constant annual PUE. Average electrical load is average IT power draw divided by installed IT capacity. It does not represent occupancy or billable utilization.
The default example
At 1,000 kW IT capacity and 80% average load, Scenario A uses PUE 1.30 and $0.06/kWh: 9,110,400 kWh and $546,624 per year. Scenario B uses PUE 1.60 and $0.09/kWh: 11,212,800 kWh and $1,009,152. The difference is $462,528.
Both PUE and tariff change in this comparison. It does not isolate either effect. Align the other inputs to study one assumption at a time.
What is outside the boundary?
Capital costs, financing, fixed and demand charges, taxes, backup fuel, maintenance, connectivity, hardware replacement and customer revenue. This calculation cannot establish project profitability, peak connection demand or a preferred location.
- The Green Grid — Power Usage Effectiveness ↗
Definition of PUE. Scenario inputs on this site are our own illustrative assumptions.