Читать книгу Maintaining Mission Critical Systems in a 24/7 Environment - Peter M. Curtis - Страница 58

Years ago, the Direct Current Data Center gained significant interest due to its ability to operate more efficiently, although today, it is still relevant, it has not been scaled as we thought it would. That being said, all of our modern electronic equipment today relies on solid‐state semi‐conductor technology, which will only operate on direct current, or DC. According to the Green Buildings Forum, 72% of the energy used in the U.S. is consumed in commercial real estate buildings. A study by the University of Virginia shows that 80% of this energy is used by semi‐conductor technology, which means this much AC power must be converted to DC. The 2007 EPA “Report to Congress on Server and Data Center Energy Efficiency” shows that data centers in the United States have the potential to save up to $4 billion in annual electricity costs through more energy‐efficient equipment and operations. One movement to accomplish this that is currently gaining acceptance among data center designers, and garnering support from the Electric Power Research Institute (EPRI), is the use of a direct current distribution system.

When we step back and look at the end‐to‐end power distribution in a conventional data center, we see several power conversions taking place. Incoming AC utility power is first rectified to DC at the UPS for the purpose of connecting to DC battery storage. It is then inverted back to AC for distribution to the server racks. At the racks, the AC is then rectified back to DC again in the power supplies for each server. We ask ourselves ‐ are all these back‐and‐forth conversions really necessary? The answer is “No.”