Calculator 03 · Power

From IT load to what the grid sees

Set the IT load, PUE and load factor. See peak grid demand, where the power goes, a year of energy, its cost and the homes it would supply.

Inputs

Critical IT loadMW

PUE

Total facility power divided by IT power.

Load factor%

Average draw as a share of peak across the year.

Power price (example)$/MWh

All-in delivered cost. Replace with your tariff.

Power flow at peak

Grid demand at peak

130MW

What the utility has to plan for

IT load

100MW

Overhead

30MW

Cooling & losses

A year of operation

Annual energy

911GWh

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Same energy as running at full peak for 7,008 of the year's 8,760 hours.

Energy cost at your price

$63.8million / yr

In household terms

Same energy as

84,426homes

Average U.S. home, about 10,800 kWh a year (EIA, 2022)

Each square = 1,000 homes

For early planning only. Results follow from the inputs and the stated assumptions; they are not engineering, financial or legal advice.

How the math works

Peak demand = IT load × PUE

Power usage effectiveness is total facility power divided by the power reaching IT equipment. Multiplying the critical IT load by PUE gives the facility's demand at peak, which is the number a utility plans for. The difference is overhead: cooling, power conversion losses and lighting. See PUE and energy efficiency.

Annual energy = peak × 8,760 hours × load factor

A year has 8,760 hours. The load factor is the average draw as a share of peak, so the annual energy is the peak demand across every hour, scaled by that share.

Cost and homes

Energy cost is annual MWh times the price you enter, which starts at an example value. The homes figure divides annual energy by about 10,791 kWh, the average yearly electricity sold to a U.S. residential customer in 2022 according to the U.S. Energy Information Administration.

Questions

How much power does a 100 MW data center draw?

If 100 MW is the critical IT load, the facility draws IT load times PUE at peak: about 130 MW at a PUE of 1.3. If 100 MW is already the facility total, use it directly as the grid demand.

What PUE should I use?

Use the design PUE for the facility if you have it. New liquid-cooled and hyperscale designs run lower; older enterprise rooms run higher. The presets are illustrative points along that range.

What load factor is realistic?

It depends on how full the facility is and how steady its workload is. A campus that is still ramping up runs far below its eventual peak, so model the ramp in phases rather than with one number.

Is the energy cost a quote?

No. It is annual energy times the price you enter. Real bills include demand charges, transmission and other components that vary by tariff and utility.