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
•
•
Desktop and laptop (“beyond the data center”)
Servers, storage, network (data center)
•
Power + cooling
• Waste stream disposal
• Energy source sustainability
• Compute energy consumption
• Site infrastructure energy overhead
Data Center Energy Dashboard
“As Found”
As Found
Data
Center
Energy
Overhead
Energy Losses
Waste
Site
Infrastructure
Overhead
Best
Practice
Efficiency
Waste
Best Practice
Hardware
Overhead
Idle
Productive
Output
Comput
e
Active
IT Hardware
“Plug”
Load
Data Center Energy Dashboard After a
“Green Tune-up”
Data
Center
Energy
Overhead
Energy
Losses
• Increased IT asset utilization
• Increased energy efficiency per IT watt
• Increased use of IT and Facility Best Practices
Site
Infrastructure
Overhead
Best
Practice
Efficiency
Best Practice
Hardware
Overhead
Idle
Comput
e
Productive
Output
Active
IT Hardware
“Plug”
Load
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 Centers
Leadership 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 Flow
Energy Overhead = IN ÷ OUT
UPS Powered
Critical Pumps
UPS
IN
PDU
OUT
Primary
Switchgear
Chillers
Cooling Towers
Pumps
Engine
Generator
Plant
Cooling Units
Misc. Loads
Computer Equipment Critical Load
Power
Utility
UPS Powered
Cooling Unit Fans
Battery
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
•
Increase computer room IT intake temperature -77°F
•
•
•
Turn off unneeded cooling
Correct cooling unit setpoints (eliminate dueling
cooling units)
Increase chilled water temperature
Appropriately utilize free cooling
• Increase site capacity utilization
AC Vs. DC Power Flow
UPS Powered
Cooling Unit Fans
UPS Powered
Critical Pumps
UPS
PDU
Primary
Switchgear
Chillers
Cooling Towers
Pumps
Engine
Generator
Plant
Cooling Units
Misc. Loads
Computer Equipment Critical Load
Power
Utility
Battery
DC Power Improves Both Hardware And
Site Infra. Overhead Efficiency
As Found
Data
Center
Energy
Overhead
Energy Losses
Waste
Site
Infrastructure
Overhead
Best
Practice
Efficiency
Waste
Best Practice
Hardware
Overhead
Idle
Productive
Output
Comput
e
Active
IT Hardware
“Plug”
Load
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
Cooling
• 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)
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)
Free-Cooling Choices
• “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)
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
•
•
Desktop and laptop
Servers, storage, network
•
•
•
Direct Current
Water vs. air cooling
Free-cooling
• Waste stream disposal
• Energy source sustainability
• Compute energy consumption
• Site infrastructure energy overhead
Questions?