Eco-Mode: Benefits and Risks of Energy Saving Modes of UPS Operation

1,868 views

Published on

Many newer UPS systems have an energy-saving operating mode known as "eco-mode" or by some other descriptor. Nevertheless, surveys show that virtually no data centers actually use this mode, because of the known or anticipated side-effects. Unfortunately, the marketing materials for these operating modes do not adequately explain the cost / benefit tradeoffs. This presentation shows that eco-mode provides a reduction of approximately 2% in data center energy consumption and explains the various limitations and concerns that arise from eco-mode use. Situations where these operating modes are recommended and contra-indicated are also described.

Published in: Technology
0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,868
On SlideShare
0
From Embeds
0
Number of Embeds
13
Actions
Shares
0
Downloads
26
Comments
0
Likes
2
Embeds 0
No embeds

No notes for slide

Eco-Mode: Benefits and Risks of Energy Saving Modes of UPS Operation

  1. 1. Eco-Mode: Benefits and Risks of Energy Saving Modes of UPS Operation Schneider Electric Data Center Science Center White Paper #157
  2. 2. Introduction This paper shows that eco-mode typically provides a reduction of about 2% in data center energy consumption and explains the various limitations and concerns that arise from eco-mode use. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 2
  3. 3. Eco-mode Introduction •Overall system architecture •Right-sized system design •Individual devices •Operational decisions © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 3
  4. 4. Simple diagram of power flow of a double-conversion, online UPS…… Bypass Path STATIC BYPASS SWITCH Online Path AC DC DC AC RECTIFIER INVERTER BATTERY © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 4
  5. 5. Online and Eco-Mode Operation Online mode Eco-mode Comment Normal Eco-mode exposes operation Rectifier/Inverter Bypass the load to raw mains O li d During a power disturbance Inverter Inverter Online mode requires no path change during power disturbances During a fault Bypass Bypass Extremely rare condition event © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 5
  6. 6. Output waveforms of 275 kVA UPS in eco-mode responding to a power failure…… Upper waveform is output voltage, lower is output current © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 6
  7. 7. Advanced eco-mode ●Result of recent advances in firmware control schemes and electrical design ●Primary power path during normal operation is the same as standard or “classical” eco-mode: through the bypass path ●But, the inverter remains “ON”, operating in parallel with the input w/o actually handling the load current ●Since the inverter is already “ON”, it can more seamlessly take over the supply to the output when there is a mains failure Schneider Electric Galaxy VM UPS with ECOnversionTM © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 7
  8. 8. Standard vs. advanced eco-mode UPS operating in standard eco-mode UPS operating in advanced eco-mode © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 8
  9. 9. Additional advantage of advanced eco-mode… ●Improved filtering function ●Reduces harmonic injection back into Utility mains or standby generators ●In principle, filtering function works at nearly the same level and quality as a double conversion UPS not operating in eco-mode © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 9
  10. 10. Advantages come with a tradeoff… ●Overall efficiency of the UPS is less ●It’s a small difference, however… ●0.5% - 1.0% range ●Efficiency less than standard, but better than traditional online mode © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 10
  11. 11. Efficiency Improvements: PUE of Typical Data Centers © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 11
  12. 12. Efficiency Improvements: PUE Improvement © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 12
  13. 13. Efficiency Improvements: Eco-mode Eco-mode corresponds to a savings of 3.3% of total energy use and US $20 000 year 20,000 per year. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 13
  14. 14. Efficiency Improvements: Eco-mode (1/2) Considerations of eco-mode include: •Loss of electrical protection Energy saved depends on: •Specific equipment •p •Reliability impacts •Operations issues Loading of data center •Cost of electricity These factors often cause operators to decide against eco-mode. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 14
  15. 15. Loss of Protection: UPS Systems Virtually all equipment sold today is immune to mains frequency variations and designed to accommodate any variations of mains voltage within a specified operating range. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 15
  16. 16. Lost of Protection: Response to Power Problems 1 • Power problem is detected p • UPS determines how to 2 respond 3 • UPS inverter is energized* 4 • Transfer switch is actuated *NOTE: in advanced eco-mode, inverter is already energized © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 16
  17. 17. Loss of Protection: Power Problem Situations Power problems: ● Transformers may trip breakers ● Loss of power leads to overloads and dropped loads ● Protective devices on pumps and fans may operate ● Non-server IT devices are not robust in handling dips and sags ● Static switches cannot protect loads from overvoltage © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 17
  18. 18. Harmonics & eco-mode… Harmonic issues will not be a factor in most data centers, but the use of eco-mode may require that they be studied or mitigated. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 18
  19. 19. Reliability Impacts: Thermal Shock and Cycling Eco-mode: •Primary cause of failure of electronic power systems •Applied when UPS is needed the most Normal UPS operation: •No shock when power fails •UPS will go into bypass © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 19
  20. 20. Reliability Impacts: Battery Life Battery Operating Temperature •Battery Wear •Eco-mode requires transfer more Strongly affected by UPS design •May operate at higher t t i d often •Wear depends on implementation of eco- temperatures in eco-mode mode © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 20
  21. 21. Reliability Impact: Fault Clearing When the UPS is in eco-mode, it can be very difficult to distinguish an output fault from a loss of input power: an additional factor that should be considered. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 21
  22. 22. Effect on Operations: Consequences Testing for Adjusting capability sensitivities or delays Establishing Utilizing procedures power p forensics © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 22
  23. 23. Conclusion As data center designs become more standardized, IT equipment continues to improve, and real world experience using eco-mode accumulates, predictability and confidence in eco-mode will improve and its application may begin to expand, especially in data centers with lower availability requirements. © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 23
  24. 24. Resources List The Different types of UPS Systems APC White Paper 1 Making Large UPS Systems More Efficient APC White Paper 108 An Improved Architecture for High- Efficiency, High-Density Data Centers APC White Paper 126 Browse all APC white papers http://whitepapers.apc.com Browse all APC TradeOff Tools™ htt //http://t l tools.apc.com © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 24
  25. 25. Thank You Questions? © 2014 Schneider Electric All Rights Reserved – Eco-mode: Benefits and Risks of Energy Saving Modes of UPS Operation – June 2014 25

×