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Generator Delays May Slow Data Center Projects
miller60 writes "The data center building boom is causing backlogs for new generator orders, with some companies reporting delivery delays of up to a year for new 2,000kw units, which are the current standard for mission-critical facilities. Generator availability is 'the No. 1 thing that will drive your construction schedules,' according to Equinix, which is building centers in three major markets. 'This will be a big issue for the next wave of data center builds,' says another industry executive. Used generators and smaller units tend to be more available than the 2 megawatt units, but companies targeting the enterprise sector may be wary of relaying on used units or smaller generators than those powering competing facilities."
Well, converting an existing engine gives you the same, if not more, concerns as getting a used generator. As TFA mentioned, there's no problem finding used 2MW generators, but it's the stigma of using used equipment period.
Add to that the changes and parts necessary to change engines geared to creating propulsion to engines geared to creating electricity.
I doubt any company who considers their data center a key component of thier infrastructure to risk their backup solution on an untested refurbished generator.
On your comment about data center size: Consolidation is the buzzword of the decade. 'Big boy' data centers start at 2MW and get BIGGER. It's not uncommon for a main site facility to be closer to 4MW. These are usually fed from the grid at the 14kV level, often from dual substations. Yes it's a lot of CPUs and supporting equipment, but thats the way we like em!
Your question on two generators vs. one: Redundancy does NOT come from two half sized units doing a single job, it comes from two FULL sized units each doing half the job. Having two half sized generator units means losing one will cause failure. With a 10,000HR MTBF per unit (rough number used for demonstration) you get a system MTBF of 5,000HR, NOT what I would call redundant! You would need at least 3/2 redundancy (3 generators doing the work of 2) to have a reasonably reliable replacement for a single large unit.
Then you have to keep them phased together. That can be complicated and error-prone. When you're operating on diesel power and lose a generator, the load gets dumped on the remaining generators, which can cause large frequency errors and brownouts. To put a spare generator online, you have to match frequency and phase with a system that is under severe stress. It can get ugly.
Mea navis aericumbens anguillis abundat
I see a lot of posts that 2MW is a lot of power. Perhaps.
There are many facilities out there with 10-30 2MW generators. I personally worked on a facility that had 18. 12 were for "critical load", that is, things fed via UPS's. This included all of the servers and networking equipment, the NOC, emergency lighting, fire supression systems and soforth. The other 6 were for "emergency load", these were things that did not need UPS protection (they could go down), just not for long. Virtually all of this load was air conditioning. So when the power went out the A/C's went off and came back 30-60 second later on generator, while the servers and all stayed up the same time.
While big, it's far from the largest facility out there.
Now, why would you buy one generator? Well, many buildings use bus variations (the whole N+1, or N+2 thing). So you build your data center for all 18 generators (as above), but install 6 and 3, or half the capacity. You now wait for the building to fill to 25-30%, and then start adding more generators, one at a time. However, they now have to be matched to the other generators.
Now, why are data center generators special? Well, to switch from one AC source to another the two loads must be approximately in phase (there is some tolerance, but it's small). So in order to be able to switch between generators, switch from UPS to generator, and all that other stuff you need additional circuitry to keep the generator just so. While the engine block and generator were the same as say a diesel locomotive, there were some additional sensors, lots of additional computer control, and some additional quick start features.
Most sites want their backup generators to be "ready to load" in 15-30 seconds. Indeed, several manufacturers make 10 second ready to load units. However that requires things like engine oil and coolant heaters that basically keep the entire motor warm 24x7x365. These are not found on industrial generators or locomotives.
So, they really are special, high tech tight tolerance units designed to work in a system. When you connect to WoW or your other large game you're probably one one of a thousand servers run by that company, who is one of but hundreds of companies in the larger colo facilities. It's not uncommon to find 50,000 servers under a single roof. So you need lots, and lots, of 2MW generators.