DC Power Production, Delivery and Utilization
Intel has estimated that power consumption can be reduced by about 10%, and others have projected even higher reduc- tions. Less heat would therefore be generated, lowering the cooling load of the facility. Other benefits of a DC power deliv- ery system are also possible. For example, Baldwin Technolo- gies, which does system design, has promoted benefits of a DC power delivery system for data centers.12 These estimated ben- efits are based on vendor claims, rated performance of com- ponents, as well as improvements that Baldwin anticipates will derive from its own DC power delivery system design. The benefits and estimated performance improvements include the following:
A lower number of components are needed, leading to lower maintenance costs and greater reliability.
DC power distribution delivery is modular and flexible, so systems can grow with load requirements.
Busways with double end-feed features allow for re- dundant DC sources at critical loads.
No down-stream static or transfer switches are required, and voltage-matched DC systems can inherently be coupled together.
DC distribution eliminates harmonics.
Grounding is simplified
Management software and controls are available.
DC distribution eliminates power factor concern.
Server reliability may be increased by as much as 27%.
Baldwin’s DC power system is being demonstrated at the Pent- adyne Power facility in Chatsworth, California (see Figure 11), which employs off-the-shelf equipment available from several manufacturers, including:
An EPRI White Paper
Rectifiers that convert utility- or generator-supplied AC power to DC (500 VDC)
Energy storage, in this case not batteries, but rather a flywheel-based system that can provide power to a 500 VDC bus if AC sources are lost
Equipment racks with DC distribution entailing con- nectors that enable feeding power from two separate 500 VDC sources for redundancy
DC to DC converters for conversion of 500 VDC power to low-voltage DC (e.g., 48V, 24V, 5 V, etc.) as required by server equipment
Figure 11. Chatsworth facility