Edison's Revenge: Will DC power rise again?

DC Power Has Risen! It is here now !

My personal opinion is that Mr. Rasmussen seems to be his own worst enemy when discussing the DC power system for Data Centers. There is a total DC power solution available for Data Centers! Mr. Rasmussen was again made completely aware of it at the Uptime Charrette in New Mexico by Validus DC System's founder, inventor and patent owner Rudy Kraus.

This is a complete system that is simpler, safer, more efficient and much more cost efficiently green than any AC or DC system currently available . The Validus System is available now and is being implemented by major international concerns! The inaccurate myths spread by proponents of an industry that has narrow mindedly monopolized the Critical Power Industry for so long are simply not true! Validus DC Power System
in the Data Center is not more dangerous than AC. It is more efficient and easier to understand.

Rudy Kraus is a Data Center visionary who after 25 years of Data Center infrastructure design searched for a better way to Power Data Centers. He built on the telecom model of using 48vdc and designed a complete system that is not only more efficient, but has many green benefits. By today's pricing standards, the total cost of ownership between an AC and Validus DC system can bring a considerable Return On Investment. This just doesn't happen in the AC world of Critical Power.

Anyone who wishes to learn more about the truth of DC should contact me or connect to www.validusdc.com.
Joe

The Green Grid finally

The Green Grid finally released its report on this subject to the public. To see the pros and cons of various AC and DC distribution schemes read Qualitative Analysis of Power Distribution Configurations for Data Centers. Seven options are summarized. Follow up reports will analyze each in detail.

DC is not dismissed on its

DC is not dismissed on its transmission loss it is what effect it has on the human body, hence the danger factor, AC throws you from the current cooks from the outside in, DC pulls you into the current and you cant get away plus it cooks you inside out, i however see that DC systems can be vastly superior over AC, less heat generation less power requirements, look at a car, its 12V DC, stable, and made to last quite some time, i do want to see how they address DC hum being introduced by default, look at a sound system, DC hum is all over most of the time, unless it runs an isolated loop

If DC gets distributed at a

If DC gets distributed at a few hundred volt level, how efficient are the converters that would be required to drop the voltage down to the 10V and less level used by most ICs?

AC doesn't lose less voltage

AC doesn't lose less voltage in transmission than DC, it's just easier to transform and more versatile in driving industrial motors (multi-phase AC made it easier/cheaper to drive high power motors and eliminates brushes).

In Edison's time transforming DC from the high voltages that allow efficient long-distance distribution to lower voltages that would be safe in a home was expensive. Such DC conversions are easier now, but still unusual, there are only a few high voltage DC transmission lines. Transmission line loss was why Edison had small power stations about every mile. If he ran the wires much farther than that his +/-100V DC system lost too much power in the wiring. Tesla's multiphase AC power could bring high voltage 25Hz power in from Niagra without trouble.

DC data centers would save power by eliminating the power conversions that backup power systems tend to introduce. Maybe they should just use AC batteries. :*)

Jeez! I hope Mr. Rasmussen

Jeez! I hope Mr. Rasmussen was misquoted here: "There's a good reason that Edison's DC power lost out to Tesla's AC design as the nation's power distribution network, he says: DC doesn't work." If that really is what he said, a history lesson is in order - DC was always considered superior, but AC won out for the distribution network because it loses less voltage in transmission....

I am investor in Validus DC

I am investor in Validus DC Systems, a start up attacking the problem you are discussing. Validus has designed an end to end DC power distribution system that distributes DC power through a data center and feeds 48V DC servers through a Power Converter Unit located adjacent to the server racks. Depending upon the redundancy configuration of the data center, it offers compelling power savings and increases server density versus conventional designs. Validus' design eliminates the bulky copper cabling that is associated with tradition DC systems in telco central offices. I would observe that APC's enjoys considerable profits from its existing system design hence its reluctance to drive DC. There continues to be confusion in the market because the power incumbents do not want to canibalize their product lines and the server manufacturers are waiting for customers to demand new solutions. Customer adoption is challenging because IT and Facilities have develop a common strategy that changes their historical purchasing patterns. I think 2008 will see the early stages of a shift to DC.

I find it interesting that

I find it interesting that while Neil Rasmussen argues against the use of DC in the Data Center. American Power Conversion has developed InfrastruXure ® which could easily be the basis for a DC powered data center.
The InfrastruXure ® concept of incrementally adding distributed power is an excellent idea. From an efficiency point of view it goes a long way to reducing the losses that are incurred when large capacity power conversion systems such as large UPS are operated well below their rated capacity.
I have never understood therefore why they continue to base the power conversion element of InfrastruXure ® on an AC UPS. A 48V DC version would remove another two stages of inefficient power conversion and because the power systems are located adjacent to the loads they are powering, there would be no requirements for the heavy duty copper distribution that is so often quoted as a reason for not using DC.