When I attended Emerson’s AdaptiveXchange show in Baltimore last week, I had a chance to see whether I could glean anything new about data center power and cooling strategies. While many presentations were pretty product oriented, I sat in on a few where the speakers made some compelling and strategic arguments. In particular B.J. Sonnenberg and Ed Miro — Emerson regional sales manager and product manager, respectively — gave an informative presentation on why 48-volt direct current (DC) is such a good idea.

The discussion was in the context of Power over Ethernet (PoE), which basically uses the communications infrastructure to power network devices, such as phones, security cameras and laptops. This kind of infrastructure works on a 48 V system; telco companies have used it for years. As Bob McFarlane’s power efficiency discussion at Data Center Decisions earlier this year highlighted, DC is a more efficient way to get power to equipment; using DC involves fewer power conversions, thus reducing power loss.

The argument is that if you have a 48 V infrastructure built into your system that is powering your office devices anyway, why not bring in 48 v power distribution units (PDUs) and power everything else? You get more efficient and reliable power and it can be centrally monitored and controlled. It’s certainly safe enough, a concern that was brought up during Sonnenberg and Miro’s discussion.

But the session ended before I could ask about the downsides (there are always downsides), so I asked a salesperson on the sales floor why more people aren’t doing this. He said that most hardware manufacturers don’t offer 48 V compatibility as a standard power connection. You have to request it and pay additional costs to make your equipment 48 V-ready. Also, 48-volt PDUs come at a premium (the salesperson didn’t know Emerson’s starting price because each application is unique, he said). And unless you need high availability, you can go with standard power and save money outfitting your data center with new equipment.