Data Centers And DC Power

mstansberry writes "In the final article in a series on the price of power in the data center, IT pros weigh the pros and cons of direct current-powered servers. A limited number of companies make servers with the power supplies removed with DC power distributed to multiple machines from a single unit. It saves power by skipping an extra conversion from alternating current (AC). Telcos have been using this method for years, but some data center pros are leery of taking on the new systems. It's not something people are familiar with and if they break down, you have to hire a specialized engineer to come fix them. But if they're saving even half of what they're reported to save on the electric bill, companies could afford to hire the engineers." We've reported on previous articles in the series.

Comments

Re:What about houses?

[n0dalus]

I thinks it's a really good idea.
If there were several pins, many different voltages would be possible, and a device could even use more than one voltage from one plug (eg, it could draw 2V for a relay, 4V for a power indicator, and the standard AC for the actual thing it's powering.)
By not having to have transformers and big resistors inside all the household devices, there would be huge savings in power, things wouldn't get so hot, wouldn't need such big heatsinks, there would be far less electromagnetic radiation around the place (which is probably responsible for a lot of people getting sick etc), and it's safer too (devices that only need a small DC power source won't electrocute you when you drop them in some water.)

Re:correction

[ArsenneLupin]

Either way, there is still only one conversion: 110AC -> 12/-12/5vDC.

Nope, you save two conversions.

Without DC distribution, you have AC->DC->AC in the central UPS, and then AC->DC in each computer's power supply.

With DC distribution, you have AC->DC in the central UPS, and no conversion in the computers.

You get down from 3 conversions to 1.

DC in Telco

[Comen]

I started working with IP in a small ISP. We were bought by a loal Telco and over the years have got used to having all our routers and switches running on DC current.
One thing telco companies do well is DC power, they have alot of skill in providing multiple DC feeds from DC power systems, with battery backup and generators all in line.
I would imagine that any big server farm would benefit from this kind of setup. Especially when you have people runnnig the lines that are as good as some of the guys in the telo world, they can really make the wiring look like a art in some places.

Re:What am I missing?

[GigsVT]

The DC step in the middle is so you can chop it into a high frequency square wave. You save power and space because you can vary the duty cycle of the square wave for regulation, and the high frequency allows for smaller components.