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The Environmental Cost of Cloud Computing: Assessing Power Use

and Impacts Jonathan G. Koomey, Ph.D.

http://www.koomey.com Lawrence Berkeley National Laboratory &

Stanford University Presented at Green:Net

San Francisco, CA March 24, 2009

For users, the cloud offers infinitely scalable computing

on demand

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So why should cloud users care about power use?

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Power use strongly affects costs for “in-house” IT

services (the alternative to relying on the cloud) AND

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Cloud computing suppliers have two inherent

advantages on power and costs over “in-house” IT

(load diversity and economies of scale)

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(As an aside, most people think the true total cost for “in-house” IT is far lower

than it actually is)

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Data centers, where the cloud resides, are where the world of bits meets the world

of atoms

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The cloud uses electricity. How much?

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World data center electricity use, 2000 and 2005

Source: Koomey 2008

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How much is 152B kWh?

Source for country data in 2005: International Energy Agency, World Energy Balances (2007 edition)

Turkey

Sweden

Iran

World Data Centers

Mexico

South Africa

Italy

Final Electricity Consumption (Billion kWh) 0 50 100 150 200 250 300

Trends push power use both up and down

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Pushing power use up… •  Increasing demands for

–  E-commerce –  VOIP –  Internet search –  software as a service –  video downloads –  resilience in the face of disaster –  regulatory compliance (e.g. Sarbanes-Oxley) –  IT-enabled business transformation

•  More transistors on a chip + more RAM + more volume servers

Summary: Delivery of IT services is

increasing rapidly

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Pushing power use down…

•  Virtualization/consolidation •  Cooling and power constraints •  Recognition of constraints by the C level •  Metrics

– Servers + other IT equipment (Spec Power, 80 plus, E*)

– Site infrastructure •  Utility rebates (PG&E)

Summary: Information technology is

becoming more energy efficient at a furious pace

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Internet electricity intensity

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Source: Taylor and Koomey (2008) for 2000 and 2006 data. Trends for 2000 to 2006 extrapolated to 2008 by JK.

Electricity per GB transferred down 30% per year!

Data center costs are strongly affected by IT power use

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Annualized data center costs

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Two important equations

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Power related terms

In spite of our historical progress, there’s still great potential for improving the energy efficiency of data

centers

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Many efficiency opportunities

22 Source: EPA report to Congress 2007

Improving the energy efficiency of data centers is as

much about people and institutions as it is about

technology

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Efficiency opportunities

•  Improve asset management and utilization (multiple benefits)

•  Improve efficiency of components (e.g. power supplies)

•  Implement consistent metrics and track over time

•  Align incentives to minimize True Cost of Ownership

•  Think “whole system redesign” (RMI)

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Misplaced incentives •  Energy, efficiency, and performance metrics

not standardized •  Not charging per kW but per square foot •  Split accountability

–  Who pays the bills, IT or facilities? –  Who bears the risk of failure?

•  Hierarchy and culture differences •  Piling safety factor upon safety factor •  Not focusing on total costs for delivering

computing services

Cloud computing suppliers have at least two big

advantages on power and costs over “in-house” IT

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1) Diversity: spread loads over many users,

improving hardware utilization

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2) Economies of scale: implementing technical + organizational changes is

cheaper and easier than for small IT shops

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The biggest environmental story about information

technology (IT) is not direct electricity use (which is

relatively small) but how IT affects efficiency in the

broader society 29

Why?

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Moving electrons is always less environmentally

damaging than moving atoms

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Example: paper vs. PDF

•  Mass of paper = 5 g/sheet •  Mass of electrons to move a 1 MB PDF

file of that page (based on average network electricity intensity of 7 kWh/GB) is 1.7 x 10-5 g

•  Ratio of paper mass to electron mass ~ 300,000

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Conclusions •  The cloud is responsible for 1-2% of the world’s

electricity use. •  Absolute electricity use growing fast (doubling

every 5-8 years) •  IT services are growing much faster than

electricity use (doubling every year or two). •  Electricity productivity, defined as computing

services delivered per kWh, is increasing rapidly and this trend promises to continue.

•  The indirect environmental and productivity benefits of IT are likely to be more important than direct electricity use.

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Key web sites

•  EPA on data centers + 2007 Report to Congress http://www.energystar.gov/datacenters

•  LBNL on data centers: http://hightech.lbl.gov/datacenters.html

•  The Green Grid: http://www.thegreengrid.org/ •  The Uptime Institute: http://www.upsite.com/

TUIpages/tuihome.html •  SPEC power: http://www.spec.org/power_ssj2008/

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References •  Koomey, Jonathan. 2007a. Estimating regional power consumption by servers:

A technical note. Oakland, CA: Analytics Press. December 5. (http://www.amd.com/koomey)

•  Koomey, Jonathan. 2007b. Estimating total power consumption by servers in the U.S. and the world. Oakland, CA: Analytics Press. February 15. (http://enterprise.amd.com/us-en/AMD-Business/Technology-Home/Power-Management.aspx)

•  Koomey, Jonathan, Kenneth G. Brill, W. Pitt Turner, John R. Stanley, and Bruce Taylor. 2007. A simple model for determining true total cost of ownership for data centers. Santa Fe, NM: The Uptime Institute. September. (http://www.upsite.com/cgi-bin/admin/admin.pl?admin=view_whitepapers)

•  Koomey, Jonathan. 2008. "Worldwide electricity used in data centers." Environmental Research Letters. vol. 3, no. 034008. September 23. <http://stacks.iop.org/1748-9326/3/034008 >.

•  Taylor, Cody, and Jonathan Koomey. 2008. Estimating energy use and greenhouse gas emissions of Internet advertising. Working paper for IMC2. February 14. <http://imc2.com/Documents/CarbonEmissions.pdf>.