1. Reliability and Energy Efficiency – Not Mutually Exclusive
William Tschudi
Principal Investigator
Lawrence Berkeley National Laboratory

2. Acknowledgements California Energy Commission
Pacific Gas and Electric Company
Uptime Institute
Critical Facilities Roundtable
Rumsey Engineers
RMI
E Source
Power Supply Manufacturers Association
Industry Partners (Too many to name all)
Subcontractors:
EYP Mission Critical Facilities, Ecos Consulting, EPRI-PEAC

3. Energy Intensive High-tech Buildings

4. We Also Operate Data Centers

5. Why Research Data Centers?
Overview
Why Research Data Centers?
Utilities were receiving requests for unrealistic power densities
A lot of misinformation was (is?) circulating
Large continually operating base loads
We saw large energy efficiency opportunities in other High-Tech buildings
Technology improvements are transferable to other building types

6. Prior Data Center Research
Overview
Prior Data Center Research
Research “roadmap” for the CA Energy Commission
Participation in design charrette organized by Rocky Mountain Institute
Energy benchmarking and case studies for 14 data centers
Market assessment in CA

7. Current Data Center Research Activities
Benchmarking and Best Practices
Investigate UPS Efficiency Improvement
Investigate Power Supply Improvement
Develop performance metrics – computing horsepower and energy use
Demonstration Projects
Technology Transfer

8. Benchmarking
Energy Benchmarking
Benchmark (measure) energy use in 6-10 additional data centers
Energy intensity and end-use
System and component efficiency
Efficiency improvement suggestions
Solicit additional benchmarks from other sources
Identify and analyze better performing systems and document in “Best Practices” summary
Develop self-benchmarking protocol

9. Electricity Flows In Data Centers
HVAC system
local distribution lines
lights, office space, etc.
uninterruptible
load
UPS
to the building, 480 V
computer
equipment
PDU
computer racks
backup generators

10. IT Equipment Loading Benchmarking
Both LBNL and Uptime Institute found average IT equipment loading at
~25 W/ft2

11. Projecting IT Load When Fully Loaded
Benchmarking
Projecting IT Load When Fully Loaded
(W/Sq.Ft. of electrically active floor space)

12. Data Center Benchmarking

13. Benchmarking
Chiller Comparison
Average 0.75

14. Total Chilled Water System Efficiency
Benchmarking
Total Chilled Water System Efficiency
Average 1.69

15. UPS System Benchmarking

16. Standby Generation Loss
Benchmarking
Standby Generation Loss
Several load sources
Heaters
Battery chargers
Transfer switches
Fuel management systems
Heaters alone (many operating hours) use more electricity than ever produced by the generator (few operating hours)
Opportunity may be to reduce or eliminate heating, batteries, and chargers

17. Standby Generator Heater

18. No Impact on Reliability
Benchmarking
No Impact on Reliability
Chiller and pumping efficiency
Use of lighting controls
Variable speed drives – pumps, chillers, fans
Free cooling
Improved UPS efficiency

19. Improved Reliability and Energy Performance
Benchmarking
Improved Reliability and Energy Performance
Better match systems to their loads
Improve humidity control and eliminate CRAC unit fighting
Water side economizers
Better control strategies – setpoints, cooling tower staging
Better thermal stratification – high ceilings and properly sized underfloor
Air management – delivering air where it’s needed

20. General Recommendations
Benchmarking
General Recommendations
Benchmark to know where you stand
Life-cycle cost analysis
Facilities partnership with IT professionals
Evaluate load spreading vs. compaction

21. Available Benchmark Data?
Benchmarking
Available Benchmark Data?
Sources of other benchmark data?
Please contact LBNL:
Steve Greenberg:
Bill Tschudi:

22. Benchmarking
Future Direction
Develop consensus on performance benchmarks, collect data, quantify energy savings potential
Incorporate other industry benchmark data

23. Data Center Power Delivery
UPS %
Power Dist %
Power Supply %
dc/dc %
HVAC
1,200W / 1 Ton (76%)
US Annual Energy Consumption of 30TW-h flows through this inefficient delivery path

24. Total efficiency ≈ 40% Cost of power delivery = $8,200 / 100
Power Path Efficiency
Power (kW)
MW-h
Cost
Load Cooling
3.1
113
$8,500
Loads
Systems (x100)
(not including dc/dc & ac/dc)
9.8
x 85%
Dc/dc
2.1
109
$8,200
x 70%
Power supply
5.1
x 90%
UPS
1.9
x 98%
Distribution
0.4
x 76%
Delivery Cooling
3.0
Total = 40%
Total
222
$16,700
Source: EPRI PEAC
Total efficiency ≈ 40% Cost of power delivery = $8,200 / 100

25. Improvements in Cost of Power Delivery
Power Path Efficiency
Power (kW)
MW-h
Cost ($k)
Load cooling
3.1
113
8.5
Loads
Systems (x100)
(not including dc/dc & ac/dc)
9.8
x 85%
Dc/dc
2.1
109  62
8.2  4.7
x 70%  85%
Power supply
5.1  2.1
x 90%  94%
UPS
1.9  0.9
x 98%
Distribution
0.4  0.3
x 76%
Delivery Cooling
3.0  1.7
Total = 40%  51%
Total
222  175
16.7  13.2
Source: EPRI PEAC
Annual cost reduced by $3,500 / 100

26. UPS Systems
UPS Activities
Determine the range of current UPS efficiencies, highlight more efficient designs, and provide a means for comparing their total cost of ownership (TCO).
Propose a new UPS labeling scheme that could be considered by Energy Star and other third -party efficiency labeling organizations.
Conduct a scoping study to analyze the energy efficiency savings potential and performance of a complete DC power architecture for data centers.

27. UPS Efficiency and Loading
UPS Systems
UPS Efficiency and Loading
Manufacturers data for efficiency versus load for current generation static and inertial UPS.
Based on review of more than 100 static UPS models

28. UPS Measured Performance
UPS Systems
UPS Measured Performance
Sample of 12 field measurements.

29. Measuring UPS Efficiency - “High Efficiency” Option
UPS Systems
Measuring UPS Efficiency - “High Efficiency” Option
Measured Result
Manufacturer Spec
Source: EPRI PEAC
On average, existing high efficiency modes can make a 4 to 5 % difference in UPS efficiency.

30. Analyzing UPS Performance in “High Efficiency” Option
UPS Systems
Analyzing UPS Performance in “High Efficiency” Option
Source: EPRI PEAC
In “high efficiency” mode, there can be one cycle
(16.6 msec for 60 Hz) of voltage deviation on UPS output.
Power supplies downstream of UPS can ride through this.

31. Research of Inertial Units
UPS Systems
Research of Inertial Units
Caterpillar
Pentadyne
Piller
Quoted efficiencies are in the 96% range and higher; we will be measuring actual performance in field/lab tests

32. Possible UPS efficiency labeling criteria
UPS Systems
Labeling
Efficiency and Reliability
Coordinating with International labeling effort addressing quality & efficiency.
Possible UPS efficiency labeling criteria

33. Labeling will consider non-energy, reliability issues
UPS Systems
Labeling will consider non-energy, reliability issues

34. Power Supply Activities
Measure efficiencies of current server power supplies
Field testing to document achievable energy savings
Recommend new efficiency levels to Server System Infrastructure Initiative (SSI) for consideration
Assess other PS saving opportunities in DC applications

35. Power Supplies Can Be Much More Efficient – Without Affecting Reliability Performance
The nation’s 3.1 billion power supplies waste about 3 to 4% of the entire U.S. electricity bill
Worst designs are 30 to 50% efficient
Designs already exist in the market that can bring power supply efficiencies to the range of 75 to 93% with big non-energy benefits
More efficient designs will be developed if there is incentive.

36. A consistent test protocol using a standard loading guideline & test report format will allow more visibility on power supply efficiency
Sample of our testing report – similar to the desktop power supply study

37. Server Power Supply Efficiency Test Data: Current Market
95th Percentile
efficiency
Median
% power supply loading
Source: EPRI PEAC

38. Importance of a Flat Power Supply Efficiency Curve
Since PS loading are low it is important to have a flat efficiency curve as much as possible
More design focus on efficiency when
lightly loaded is needed

39. Goals of the Power Supply Task
Long term:
Move the market towards widespread adoption of energy efficient PS in data centers
Create an energy efficiency labeling program such as ENERGY-STAR® for server power supplies

40. Power Supplies in IT Equipment

41. Power Supplies in IT Equipment

43. Server Power Supply Efficiency Lab Test Setup
Electronic Load Banks
Fluke 41 Power Harmonic Analyzer
Yokogawa Digital Power Meter
Computer Interface
Power Supply Load Test Fixtures
Server Power Supply

44. Overall Computing Efficiency
Performance Metrics
Overall Computing Efficiency
…does not relate to very low power consumption
Very Low Processor Activity…
Most of the time the GHz processor is doing activities that can be done by a MHz processor but the input power consumption is not changing much

45. Performance Metrics - limited activity includes:
An assessment of:
Server activity profile based on application/server type
Correlation of server activity and power consumption
Work with Intel, AMD, IBM, HP, and potentially others to reach consensus on metrics for some applications.
Develop efficiency guidelines based on performance metrics

46. LBNL’s Role in Demonstrations
Scoping demonstrations of technologies or strategies to improve energy efficiency in high-tech buildings
Showcase new/emerging or under-utilized technologies or approaches

47. Currently Planned Demonstrations
Heat removal from servers without fans
DC powering rack of servers
Air management improvements (PG&E)

48. Conclusion
Many strategies to improve energy performance in a data center can be implemented with no impact on reliability – in fact, many will actually improve reliability and lower capital cost.
Major industry firms are interested in supporting efficiency (and reliability) improvement.
If you want more efficient data centers – ask for them.

49. Thank You
Questions?
Bill Tschudi, Principal Investigator Lawrence Berkeley National Lab