By Randy Smith
The evolution of the edge is happening because of the need to bring computing closer to the consumer to reduce latency and manage bandwidth, but there are challenges in making that happen. As these sites become more important, demand increases to make computing availability at the edge as non-negotiable as it is in most enterprise data centers.
(Editor’s note: The Financial Times describes the network “edge” as “the name given to the many computing devices that intersect with the real world, from internet-connected cameras and smartwatches to autonomous cars.”)
Chances are you depend on edge computing inside and outside your building or campus. Consider server or telecom closets, labs, testing centers, distance learning, branch offices, and so much more.
But making these sites just “reliable” isn’t enough. To realize an effective edge strategy, these sites also must be energy efficient. It’s tempting to dismiss energy efficiency at small edge sites as an afterthought, but that would be shortsighted. True, savings at a single site may be small, but when those savings are repeated across hundreds or thousands of edge locations, those savings become significant.
With that in mind, here are five tips for increasing energy efficiency at the network edge:
- Go transformer-free: Data center managers have become increasingly comfortable with transformer-free UPS systems in recent years, but transformer-free options traditionally have been limited to larger units. That’s changing. There are more and more transformer-free UPS systems designed for smaller and mid-sized deployments. These are good options for efficiency-minded organizations.
- Leverage three-phase UPS systems: Many edge deployments are located in large buildings with readily available three-phase power. By tapping into the existing building power system, you gain access to more balanced electrical loads and utilize more efficient power technologies. Most single-phase UPS systems have an operating efficiency 89-92 percent. Best-in-class is 93. Three-phase systems typically are north of 94% and often closer to 97 percent. Three-phase also lowers installation and wiring costs and has friendlier interaction with generators.
- Higher voltage systems: It’s not news that higher voltages enable more efficient operation. Where feasible, consider using higher voltage electronics. In the U.S., delivering 208V or 480V to the output has real savings. The higher-voltage systems aren’t just more efficient; they also can save on copper and in most cases on installation costs. Couple this with a higher power factor UPS – which generally correlates to increased kW – and when scaled across multiple edge sites, the efficiency gains become significant.
- Operate in the appropriate mode: The fundamentals of eco-mode have been around for decades, although adoption in the data center only started around 2010. UPS systems operating in eco-mode generally are about 3 percent more efficient than those in standard double conversion operation, and we have established that those small improvements in efficiency can have significant impact across networks of edge facilities. Eco-mode isn’t the only option, however. Eco-mode is voltage frequency dependent (VFD). Double conversion is voltage frequency independent (VFI). There is a third mode – voltage independent (VI) – that is something of a middle ground for larger systems. It allows limited power conditioning (better than eco-mode, not as good as double conversion), and is a reasonable compromise for those seeking more efficient UPS operation without sacrificing power conditioning altogether.
- Consider DC power options: Telecom networks have been using DC power for more than a century, and the efficiency advantages tied to reduced power conversions are well known. Many IT edge facilities operate like telco access sites, creating an opportunity to replicate the telco model right down to a DC power system in favor of an AC UPS. It’s a more radical approach, but something to consider as IT and telco become more blurred at the edge.
Bottom line: The edge is more critical than ever and growing exponentially. The sheer scale of the critical edge, encompassing hundreds or even thousands of sites in some networks, makes even modest site-level efficiency gains significant. Those gains are available with the right technologies and edge architectures.
Randy Smith is a Strategic Technical Manager for AC Power, Vertiv. He has more than 18 years of experience with Vertiv and its predecessor Emerson Network Power. At Vertiv, he provides technical advice and counsel to customers requiring effective IT infrastructure solutions. His previous experience as director of program management and power application engineering, plus eight years managing large UPS projects, has allowed Smith to provide the detail and practical insight these customers expect. Randy has a BSEE in electrical engineering from University College of Dublin.