Variable reliability and capacity data center design

A design for the electrical infrastructure of a data center enables two different configurations to be utilized, including a distributed, redundant configuration that provides higher reliability and a non-redundant configuration that provides higher capacity. In the distributed, redundant configuration, each server in the data center draws power from at least two different power supply systems. This enables load shifting when a power supply system becomes unavailable, which can have the effect of increasing server reliability. In the non-redundant configuration, each server in the data center draws power from only one power supply system. Load shifting is not utilized in the non-redundant configuration, which eliminates the need to maintain reserve capacity and thereby increases capacity. Advantageously, it is possible to switch between these two configurations without making any internal changes to the data center other than modifying connections between sets of server racks and power buses.