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example,moste-commercebusinesses
tendto“leavethe lights”onaroundthe
clock—regardlessofcustomerneed.
Datacenterssimplyaren’tbuilttouse less
energywhenthere’s lessdemand. Infact,
reports indicatemost infrastructurescan
potentiallywasteupto90percentofall
powertheydraw.
This istypicalacrossthe industry,as
notedbyrecentanalysesbyMcKinsey
andCompany. Thesurveyfound
companiestypically“maxedout”atusing
only12percentoftheirpoweronactual
hardwareuse. Theremainder isspenton
keepingthem idlingandready inthe
eventof increaseddemand. Andmostof
thiswastecanbefound intheformof
inefficientpowerandcoolingequipment.
Now let’sconvert inefficientuseofenergy
intodollars. Analystsestimatethecostof
powerrunsabout11.5centsperkilowatt-
hour. Thistranslates into$1,000peryear
foreachkWof IT load. Next, themost
commonmetricusedtodeterminedata
centerenergyefficiency isPowerUsage
Effectiveness(PUE)—calculatedby
dividingtheamountofpowerentering
thedatacenterbythepowerusedtorun
theactualcomputer infrastructure. With
mostdatacentersaveragingaPUEof1.8
perkW—thismeans$1,800 inyearly
energycostsperkWof IT load. Multiply
thisnumberbythecompute loadand it
becomesclearthatpoorenergy
efficiencymeanshighercosts.
THECULPRITS
Typically, thetwobiggestculpritsof
energywaste—andthushighercosts—
are inefficientcoolingandpoorpower
equipment. Theverysystemsdesigned
tosupplyandmanagepower—suchas
UninterruptiblePowerSupplies(UPS),
transformers,switchesandwiring—can
provetobevery inefficient. Andaspower
isconsumed, it’sreleased intheformof
heat. Thismeansmoreequipmenttocool
the infrastructure,andmoredollarsspent.
Askanydatacentermanagerandthey’ll
tellyouthatback-uppower,chillers,
coolingtowers,condensersandpumps
takeasmuchenergyasthe ITequipment
itself.
Arecentarticlebacksupthisfact: “While
inefficiencies indatacentersrunthe
gamut, themajorityofenergywastecan
beattributedtocoolingequipmentwith
thesecond largest lossesfound inthe
mechanicalsystemandUPS.Ultimately,a
datacenter’soverallefficiencybeginsand
endswithaneffectivedesignforthe
mechanicalandelectrical infrastructure.”
Combinepoorplanningandolder
technologywithrisingenergycostsand
it’snotdifficulttoseewhypower
efficiency isaconcern. Sinceevery
megawattofpowerhasamultiplier
effect, it’snotuncommontoburnthrough
severalmilliondollarswithevenaslightly
inefficient infrastructure.
PowerefficiencybecomestheNo. 1
challengeacrosstheentire ITplanning
process—intermsofproductsusedand
strategic implementation.
STATICUPS: NOTMAKING
THEGRADE
Whiledaunting,costefficienciesareby
nomeansunattainable. Asoneofthe
mostessentialpiecesofthecritical
infrastructure, theUPS isagreatplaceto
start.
Bydefinition,UPS isanelectrical
componentofferingemergencypower
whenthe inputfails—ensuringcritical
dataremains intact. Incontrasttoan
emergencypowersystemorstandby
generators, theUPSdeliversnear
instantaneousprotectionfromany
interruption. WhenthinkingaboutUPS,
mostcompaniestypicallygravitateto
static-based,batterysystems. People
believemostpoweroutages lastno
longerthanafewminutes—whichcanbe
handledbythesesystems. Unfortunately,
thisapproach iswoefullyshort-sided.
Static,battery-basedUPSsystemsbring
arangeofcomplications—themost
importantbeinghighercosts. Oncethe
initial investment ismade,operatorssoon
findtheywastetimemaintainingand
updatingthesesystems. That’saproblem
whenmaintenance isoftenthefirst line
itemtargeted inanycostcuttingbudget.
Asarecentarticlepointsout: “Tofurther
aggravatematters,batteriesfailwell
beforetheirratedbackuptime intoday’s
cost-cutting,maintenance-averse
world…Batteriesworkfine ifmanagement
commitstomaintainingthem,but
typicallymanagementwillcutcostsat
anyprice. That’sthegreatweaknessof
batteries—theyarenot itemsyoucanbuy
andforget.”
Additionally,anytimeyou’re lookingata
staticbattery-basedsystem-space is
alwaysaconcern. It’sestimatedthata
five-minutebatteryof400kWtranslates
intoabout200sq. ft. Thiscouldmeanbig
money:
“This is200sq. ft.ofsupportspacefor
every2,000sq. ft.ofraisedfloor. System
redundancycan increasethefloorspace
requirementsto400sq. ft.per2,000sq.
ft.ofraisedfloor. So,nearly20percentof
thefloorspaceproducesnorevenue
becauseofthebasicUPSequipment.”
Makingmattersworse,staticbatteryUPS
systemssufferfromshort lifespans.
Batteriestypically lastnomorethanfive
years—meaningmultipleremovals,
replacementsandmaintenancecycles—
allgeneratingadditionalcosts.
Withthewiderangeofcostsassociated
withsmoothdatacenteroperation, it
wouldseemahighlyefficient
infrastructure isunattainable. Notsofast.
Diesel rotary-basedsystemshaveopened
upawholenewworldfordatacenters,
puttingenergyefficiencyfrontand
center.
ANEWGENERATIONOFPOWER
AtraditionalbatteryUPSsystem is
composedofarectifier,batteriesand
inverter. TheUPSsystemprovides
temporarypowervia itsbatteriesand
thentransfersthecritical loadtoa
standbypowergeneratorthat
supplementspowerfor longeroutages.
Ontheotherhand,aDieselRotary
UninterruptiblePowerSupply(DRUPS)
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