Cutting the Green IT Hype: Fact vs. Fiction

Kenneth G. Brill, Executive Director

Uptime Institute Inc

kgb@uptimeinstitute.org

Agenda

• What constitutes green IT?

• Innovative facilities ideas

• Direct current versus alternating current

• Water cooling versus air cooling

• Free cooling: Water versus air

• What is the business mission of IT?

• What constitutes green IT hype?

What Is Green IT?

• Energy and materials consumed in fabrication• Products (paper, hardware, components) • Data center building and site infrastructure

• Waste stream disposal• Energy source sustainability• Compute energy consumption

• Desktop and laptop (“beyond the data center”)• Servers, storage, network (data center)

• Site infrastructure energy overhead • Power + cooling

Data Center Energy Dashboard“As Found”

Waste

Best Practice

Efficiency

En

erg

y L

os

se

sData

Center Energy

Overhead

Site Infrastructure

Overhead

Compute

IT Hardware“Plug” Load

As Found Waste

Idle

Active

Productive Output

Hardware OverheadBest Practice

En

erg

y

Lo

sse

s

Data Center Energy Dashboard After a “Green Tune-up”

Best Practice

EfficiencyData

Center Energy

Overhead

Site Infrastructure

Overhead

Compute

IT Hardware“Plug” Load

Idle

Active

Productive Output

Hardware Overhead

Best Practice

• Increased IT asset utilization• Increased energy efficiency per IT watt• Increased use of IT and Facility Best Practices

Data Center Sustainability Is Determined By Zip Code

• Renewable energy sources (lowest GHG)• Wind, solar, tide (each is interruptible, space/land

intensive and can not be used for base load)• Geothermal, hydro (mostly continuous)

• Non-renewable energy sources (lowest to highest GHG)• Nuclear, natural gas, oil, coal

• Free-cooling: number of days depends on: • Zip code• Computer room temperature and relative humidity• Beware: Higher temperatures do not necessarily

save energy

“LEEDs” For Data CentersLeadership In Energy Efficient Design

• California Energy Commission is sponsoring development of Environmental Performance Criteria for data centers • Shifts the awarding of potential points toward

energy efficiency and away from bike racks• Protocol voting this fall

• Current U.S. Green Buildings Council LEED ratings are meaningless for data centers • Energy consumption 20-40x office buildings• Few people relative to building size• Outside air and windows are not necessarily

good solutions for computer room cooling

Two Locations For Measuring Site Infrastructure Energy Performance

• At the data center utility meter (must include

all forms of energy: electric, chilled water,

steam, diesel, one-pass cooling)

• At the IT hardware plug (however, UPS

output is easiest to measure and in most

cases is much more accurate)

Site Infrastructure Energy FlowEnergy Overhead = IN ÷ OUT

PrimarySwitchgear

PowerUtility

EngineGenerator

Plant

UPS

BatteryUPS Powered

Cooling Unit Fans

UPS Powered Critical Pumps

PDU

Chillers

Cooling Towers

Pumps

Cooling Units

Misc. Loads

Co

mp

ute

r E

qu

ipm

ent

Cri

tica

l Lo

ad

IN

OUT

Site Infrastructure Energy Overhead

• Ratio of energy into the data center versus what is delivered to IT hardware

• Overhead performance will depend upon: • Zip code (weather and season)• Equipment installed• Site asset utilization• Site infrastructure Tier level• Implementation of best practices

• Green Grid calls this number PUE (under revision), but has resulted in many misleading marketing claims and growing industry confusion

Data Center Energy Sources

• Electricity

• Natural gas

• Diesel fuel

• Free cooling

• Other (steam, chilled water, one-pass

cooling)

Energy Versus Power

• Energy is power over time

• Recommend using a 12 month moving

average

• Peak power determines required sizing of

component capacity

Site Infrastructure Energy Overhead

• Uncontrollable “as-built” factors affecting SIEO• Greenness of site energy sources• Site infrastructure design and component selection• Tier level and uninterruptible cooling• Weather and seasonal variation

• Controllable factors affecting SIEO• Increasing IT load as percent of site capacity• Cooling system optimization• Utilizing free-cooling capabilities• Implementation of best practices -- mainly cooling

Site Infrastructure Energy Overhead Typical Improvements

• Measure Site Infrastructure Energy

Overhead

• Correctly implement cold/hot aisle (28

steps)

• Bypass airflow <10% (seal cable cutouts,

install blanking plates, perf tile qty and

location)

Site Infrastructure Energy Overhead Typical Improvements

• Right size cooling

• Repair degraded cooling units

• Correct cooling unit setpoints (eliminate dueling

cooling units)

• Increase computer room IT intake temperature -- 77°F

• Turn off unneeded cooling

• Increase chilled water temperature

• Appropriately utilize free cooling

• Increase site capacity utilization

AC Vs. DC Power Flow

PrimarySwitchgear

PowerUtility

EngineGenerator

Plant

UPS

BatteryUPS Powered

Cooling Unit Fans

UPS Powered Critical Pumps

PDU

Chillers

Cooling Towers

Pumps

Cooling Units

Misc. Loads

Co

mp

ute

r E

qu

ipm

ent

Cri

tica

l Lo

ad

DC Power Improves Both Hardware And Site Infra. Overhead Efficiency

Waste

Best Practice

Efficiency

En

erg

y L

os

se

sData

Center Energy

Overhead

Site Infrastructure

Overhead

Compute

IT Hardware“Plug” Load

As Found Waste

Idle

Active

Productive Output

Hardware OverheadBest Practice

Direct Current Things To Consider

• IT Hardware

• Availability of hardware over life of site

infrastructure

• Premium for hardware with DC input (5x to 8x

product replacement vs. site infrastructure life

• Point of use DC vs. Data Center DC

• Voltage choices: 48 VDC vs. 750 VDC

• Code, fault protection and skills

• Water vs. air for cooling

• Water is 3,400 times more efficient

• Water to hardware (mainframe cooling)

• Water to back door or ceiling units (load

neutralization)

Cooling

Simplified Computer Room Heat Movement

Computer Product Environmental Limits

High Density Cooling Solutions (continued)

Liebert’s Vertical Top Cooler Supplemental System(up to 8 kWC per unit)

• “Open the windows” vs. Air Side or Water Side

Economizers

• Open vs. closed environment

• Relative humidity vs. reliability

• Energy cost of maintaining relative humidity in an

open environment

• Particulates and contamination

• Impact of neighbors (fire, dust, contaminants)

• Open is an OpEx play only (i.e., must still have

cooling CapEx for some portion of year)

Free-Cooling Choices

Heat Movement Holistic View

Air-Cooled Condenser Or Dry Cooler

Components include:

• Refrigerant or glycol

coils reject heat to the

atmosphere

• Fans

• Heat rejection capacity

drops significantly on

hot days

Cooling Tower -- Induced Draft Type

Components include:

• Tower and fill

• Fan

• Basin to catch cooled

condenser water

• Rejects most heat

through water

evaporation

• Fan rotation can be

reversed for deicing

Cooling Tower -- Forced Draft Type

Components include:• Tower and fill• Fan• Basin to catch to

cooled condenser water

• Rejects most heat through water evaporation

• Less appropriate for freezing climates

What Is The Mission Of IT?

• Business value vs. energy efficiency

• What will you get promoted/fired for?

• Saving energy?

• Causing downtime?

What Constitutes Green IT Hype?Reality Vs. Risk/Reward Balance

• Energy and materials consumed in fabrication• Products (paper, hardware, components) • Data center building and site infrastructure

• Waste stream disposal• Energy source sustainability• Compute energy consumption

• Desktop and laptop• Servers, storage, network

• Site infrastructure energy overhead• Direct Current• Water vs. air cooling• Free-cooling

Questions?