What does a telco need for 400 VDC to find a place in the central office 400 volts: Even though the technology isn't quite here yet, it's not just for data centers anymore

There's little doubt that 400 volts (nominal) is coming. Which architecture wins the race depends on the lifecycle cost of deploying the system and whatever politicking governs decisions in a particular carrier's engineering department. Very clearly, one of the weightiest factors in total cost of ownership is the system end-to-end efficiency. The number of power conversions between the building service entrance and the electronic systems actually using the power figures mightily in overall efficiency. Since most electronic circuit boards utilize 5 volts, 12 Volts or some similar dc potential, virtually all electronic systems employ a power supply to convert whatever is the supply voltage to the board level voltage(s). For data center systems the source voltages are 120 VAC and 208 VAC or other potentials depending on where in the world the systems will be deployed. The development of embedded dc to dc converters that will convert a nominal 400 volts dc to server board level voltages paves the way for so-called high voltage dc data centers and as of this writing it's believed that such soon will be the case. The advantages of such a topology are well known to those who have been around INTELEC for more than a few years. Improved end to end efficiency through reduced power conversion stages plays a major role in reducing the overall energy cost and environmentally, the carbon footprint. Not only is the cost of powering the electronics tamped down, but also the cost of cooling the facility. To paraphrase character Mr. Mayagi in the movie Karate Kid, the line "Wax on, wax off' he uses to teach his young student Karate stances while waxing a car. In our world, Watt in, Watt out becomes the watchword for controlling power and environmental cooling costs. With all that said, in discrete numbers there aren't all that many data centers in the world as compared with the plethora of telecommunications central offices. Therefore, improving efficiency and reducing the cost of power systems feeding the telecommunications network including central offices might just be the Holy Grail of the telecommunications energy business over the next decade or so. The commodity cost of copper aside, the sheer volume of cable, the space it takes up and the effort needed to install and one day remove it all result in a fairly high lifecycle cost of the traditional 48 volt energy system. Further, as will be shown herein, providing a high voltage dc potential and then converting it to an intermediate 48 Volt potential comes at a very high operating cost for "extra" conversion equipment and the energy lost in converter inefficiency and added cooling cost.