Over the past few weeks, I’ve posted extensively about using DC power to improve data center efficiency. In this post, I’ll be discussing some tips to make sure your data center DC power is as green as it can possibly be!
The first tip is to locate the DC power plant as close to the equipment being powered as possible. There is a tendency in data centers to want to centralize and segregate power equipment, however, the longer the distance between the supply and the load, the more loss to the resistance of the conductors, wasting power (and that’s not very green at all). This issue is even worse at lower voltages such as the standard 48VDC.
The second tip is to think copper. Bus bars, cables, everything should be bare or tinned copper. So, why not use less expensive aluminum cable and bus bars? First, aluminum has more resistance than copper, once again aggravating the distance issue, resulting in more wasted power. Aluminum also has the tendency to oxidize at the connectors, making conductor resistance even worse.
Second, aluminum is not as ductile as copper, meaning it has a tendency to loosen in the connectors, resulting in more resistance, wasted power, and maintenance to periodically tighten connectors. The third good reason no to use aluminum is that it’s far harder to install. Since aluminum is much harder to bend than copper, installing large gauge aluminum can be a real physical challenge, especially in constricted areas.
So, are there any differences in copper cable that effect the green-ness of our data center DC power plant? High strand count copper cable, such as Cobra X-Flex, is better than ordinary low strand count cable. The fine stranded cable has significantly lower resistance per foot, allowing that same gauge to carry more current than ordinary cable. Remember, the lower the voltage DC power plant, the more important reducing conductor loss becomes. The other advantage to the high strand count cable is that it’s super flexible. This makes it much easier to install, especially inside cramped cabinets. Remember, more strands = better cable!
There are several smaller things that can also be done. Use locking hardware to ensure solid connections. Coat major connections with a fine layer of petroleum jelly to protect against oxidation. Remember, anything that reduces electrical loss contributes to the greening!
These are the biggest issues to making sure that your green data center DC power plant is as green as possible. Stay tuned for my upcoming article on care and operation of the DC power plant battery string!
Vern, SwiftWater Telecom