SELECTING ELECTRICAL systems that meet an organization's needs presents a complex challenge. Facility executives must identify load density, determine the reliability required for the electrical systems and understand the future needs and implementation plans. What's more, any plan for assuring that the facility will have adequate, reliable power must be based on a detailed understanding of the business plan of the organization, a close look at the maintenance plan, and a careful review of how the facility is to be operated; from all of that information, a reasonable budget must be developed.

A starting point is to determine load density. The best way to determine the load is to assemble a detailed list of equipment to be placed in the data center. Unfortunately, because data centers need to accommodate changing equipment and rising loads, it is more common to use load projections based on square footage of usable area in the data center. To identify future needs, it is important to understand how the facility will be operated today and what tomorrow might hold. That means good communication between the information technology group and the electrical engineers is essential.

Probability studies can be used to determine the system reliability if the facility executive knows the reliability level required. If not, the facility executive must understand system redundancy and cost issues. The latter includes the tradeoff between the cost of the redundant equipment and the revenue lost when an outage occurs. The lower the risk of an outage, the higher the initial cost of the electrical system. Only by weighing costs and risks can the facility executive make the correct decision about the redundancy required.