Calculate server room energy costs, cooling load, PUE savings, and circuit capacity from server count or total IT load and voltage.

Constant-load estimates. Circuit and UPS figures are planning references; verify equipment, actual peak demand, phase balance, redundancy and local electrical requirements.

Facility overhead and billing assumptions

Blank uses estimated facility load; actual tariff demand may differ.

Server Room Cost Formula

The following formula is used to calculate the cost of a server room (power cost only).

SRC = S × (PC / 1000) × EC × T × PUE
  • Where SRC is the estimated daily energy cost ($/day), excluding demand charges
  • #S is the total number of servers
  • PC is the power consumption of each server (watts)
  • EC is the cost of electricity ($/kWh)
  • T is the total time the servers run per day (hrs); PUE is total facility energy divided by IT energy (at least 1). Use PUE = 1 for IT energy alone.

To calculate daily energy cost, convert total IT power from watts to kilowatts, multiply by facility PUE and operating hours per day, then multiply by the electricity rate. Monthly demand charges use billed peak kilowatts and are calculated separately.

What is the cost to run a server room?

Definition:

A server room cost is typically considered the daily electrical cost of a server room and omits upfront server costs and overhead costs.

How to calculate a server room cost?

Example Problem:

The following example outlines how to calculate the cost of a server room.

First, determine the total number of servers. In this case, there are a total of 500 servers.

Next, determine the power consumption of the servers. Assume each server consumes an average of 10 watts and PUE = 1 (IT energy only).

Next, determine the average time the servers run per day. In this case, the servers run all day long, so 24 hours.

Next, determine the electricity cost. The local cost of electricity in this area is found to be 0.785 $/kWh.

Finally, calculate the server cost using the formula above:

SRC = #S * PC/1000 * EC * T * PUE

SRC = 500 * (10/1000) * 0.785 * 24 * 1

SRC = $94.2 /day