Increasing the Efficiency of UPS Systems And Proving It

1
Increasing the Efficiency of UPS Systems And
Proving It!

• Richard L. Sawyer
• Director, Critical Facilities Assurance
• EYP Mission Critical Facilities
• www.eypmcf.com

2
The Problem

• 60 of US Energy bill is in buildings.
• Energy consumed by data centers more than doubled
  between 2000 and 2005 J. Koomey, Stanford
  University.
• U.S. Data center electrical bills totaled 2.7
  Billion in 2005.
• A single, moderate size server in a data center
  has the same carbon foot print as a SUV that gets
  15 MPG (R.Muirhead, Data Center Journal).
• A single rack with 6 Blade Server units consumes
  as much power as 3 kitchen electric ranges
  (24-30Kw)!

3
Relative Power Densities
4
21st Century Computing Blade Servers
Power Up to 6 kW per Blade chassis or 30 kW per
rack
5
Where does the power go?
UPS 18
Actual IT Load is 30 of Power Consumed
APC-MGE Neil Rasmussen
6
(No Transcript)
7
Strategy to Improve UPS Efficiency
IBM Blue Gene 1.2 Megawatt

• Technology Make the units more efficient.
• Selection Size the units more closely to the
  load.
• Application Use redundancy only where it is
  needed.

8
Understanding UPS Inefficiency Factors

• No-Load Losses
• Proportional Losses
• Square-Law Losses

Paying the price to process power!
9
EPRI Efficiency Curves for UPS Products
10
Typical UPS efficiency curve
Below 30 loadefficiency drops rapidly
Nominal 92 efficiency only applies when UPS load
is over 70
100
90
80
70
60
UPSEfficiency
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
UPS Load of full power rating
11
13.5 KV
13.5 KV
2(N1) System
480
480
Each side must have capacity to support both
critical loads but maintain redundancy. Total
load cannot exceed capacity of 2 UPS
Modules. EFFECTIVE DESIGN LOAD 33 of total
capacity, maximum.
Primary Bus A
Primary Bus B
UPS
UPS
UPS
UPS
UPS
UPS
Bypass B
Bypass A
Load Bank
Load Bank
UPS Output 2A
UPS Output 2B
Subsystem Bus A
Subsystem Bus B
Critical Load Bus A
Critical Load Bus B
Static Switch
Static Switch
PDU
PDU
Critical Load
12
Aggregate UPS Power Losses
13
No Load Losses

• Definition The power consumed by the UPS at 0
  load just to keep the UPS operating.
• Sources Transformers, capacitors, logic
  systems, fans, communications cards.
• Sometimes referred to as tare, constant,
  fixed, shunt and parallel losses.
• Most significant inefficiency Accounts for up to
  40 of UPS losses.

14
Proportional Losses

• Definition The power needed to process more
  power through the UPS.
• Sources Switching losses, capacitor and
  inductor impedance, internal resistance
• Proportional losses increase as the output load
  the UPS support increases.
• Proportional losses are directly related to the
  topology (internal design) of the UPS.

15
Square - Law Losses

• Definition Losses related to the amount of
  current flowing through the UPS.
• Power is the result of voltage times the current.
• Current does the work, and power is lost as the
  amount of current flowing increases, by a square
  factor, hence square law losses.
• Power loss is in the form of heat.
• Square-Law losses are 1 to 4 at higher load
  levels.

16
Power Loss Component Graph
17
Two devices with same nameplate efficiency can
have significantly different losses in actual
operating range, due to the particular
characteristics of their PROPORTIONAL and
NO-LOAD losses
Same nameplate efficiency (full-load loss)
Example Two different 100kW UPSs with 92
nameplate (full-load) efficiency
10kW
Loading where most data centers operate
Electrical Loss (Waste due to inefficiency)
UPS A TOTAL LOSS
UPS B has higher proportional loss (steeper line)
but lower no-load loss
UPS B TOTAL LOSS
UPS A No-load loss
UPS B No-load loss
But different performance at actual operating
load
0kW
No Load
Full Load
50
10
30
90
70
Equipment Loading
18
One device can even have WORSE nameplate
efficiency than another, yet have lower loss in
actual operating range, if it has a low NO-LOAD
loss
Example Two 100kW UPSs with same 92 nameplate
(full-load) efficiency
UPS A has better nameplate efficiency (lower
full-load loss)
10kW
Loading where most data centers operate
B
A
Electrical Loss (Waste due to inefficiency)
UPS A TOTAL LOSS
UPS B has higher proportional loss (steeper line)
but lower no-load loss
UPS B TOTAL LOSS
UPS A No-load loss
UPS B No-load loss
But UPS B performs better at actual operating
load
0kW
No Load
Full Load
50
10
30
90
70
Equipment Loading
19
Improving Efficiency

• Technology
• Selection
• Application

20
Improving Efficiency Fixing No-Load Loss
Effect of lowering NO-LOAD LOSS
Example 100kW UPS with 92 full-load efficiency
10kW
Nameplateefficiency goes from 92 to 94.5
Same improvement in nameplate efficiency
Loading where most data centers operate
Total loss before improvement
Electrical Loss (Waste due to inefficiency)
Total loss after improvement
Electric bill savings
OriginalNo-load loss
But waste is roughly cut in half in actual
operating range
Lowered No-load loss
0kW
No Load
Full Load
50
10
30
90
70
Equipment Loading
21
Improving Efficiency Fixing Proportional Loss
Effect of lowering PROPORTIONAL LOSS
Example 100kW UPS with 92 full-load efficiency
10kW
Nameplateefficiency goes from 92 to 94.5
Loading where most data centers operate
Total loss before improvement
Electrical Loss (Waste due to inefficiency)
Total loss after improvement
Electric bill savings
(UnchangedNo-load loss)
Waste is reduced by 10-20 in actual operating
range
0kW
No Load
Full Load
50
10
30
90
70
Equipment Loading
22
Application Efficiency Zoned Redundancy
23
Commissioning UPS Systems

• Availability
• The Cost of Downtime
• The Value of Commssioning

24
Data Center Tier Ratings
The Uptime Institute
25
Maximizing Availability
Total Time - Downtime
Availability
Total Time

• The only variable is Downtime
• Downtime sources Equipment Failures,
  Human Error, External Causes, Maintenance

Cost of Downtime drives the Value of CFA!
26
What does Downtime Cost?
27
The Reliability Curve for equipment (IEEE)
Infant Mortality Period
End-of- Life Period
High Probability of Downtime
Failure Rate
Time (Data Center Life Span)
The Bathtub Curve
28
The Value of Commissioning
Infant Mortality Period
End-of- Life Period
Minimize
Failures
Time
29
Commissioning UPS Systems

• Verify the full load performance of each module
  using load banks typical burn in is 4 hours at
  rated KW load (hint infrared inspections of all
  connections).
• Measure and verify the efficiency in the full
  operating range at 5, 10, 15, 20,
  25..........
• Verify system redundancy under design load
  levels.
• Verify failure modes (under-voltage transfers,
  bypass transfers, over load shutdown).
• Verify isolation modes for concurrent
  maintenance.

Assuring you get the reliability and efficiency
you pay for!
30
Questions?

• Richard L. Sawyer
• 518-337-2049
• rsawyer_at_eypmcf.com