DOE Proposes UPS Efficiency Standard

Thu, 08/11/2016 - 11:22 -- MrGreen

The U.S. Department of Energy (DOE) recently published a Notice of Proposed Rulemaking (NOPR) describing minimum efficiency levels for uninterruptible power supplies (UPSs). The UPS proposal is an offshoot of the DOE's recently published battery charger efficiency standard. The UPS standard is expected to save consumers as much as $4.4 billion in energy savings for products purchased between 2019 and 2048.

If adopted, the efficiency requirements would apply to the UPS product classes listed in in the table below. The standard will affect UPS products manufactured in, or imported into, the United States, starting two years after publication in the Federal Register.

The proposed requirements are expressed in average load-adjusted efficiency and are based on a UPS's rated output power (Prated) as shown below.

Proposed energy conservation standards for UPS systems

UPS Product Class Rated Output Power Minimum Efficiency
Voltage and Frequency Dependent1 0 W < Prated ≤ 300 W
300 W < Prated ≤ 700 W
Prated > 700 W
-1.09E-06 × P2rated + 6.50E-04 × Prated + 0.876
-5.63E-08 × P2rated + 7.61E-05 × Prated + 0.955
-6.22E-09 × P2rated + 3.91E-06 × Prated + 0.981
Voltage Independent2 0 W < Prated ≤ 300 W
300 W < Prated ≤ 700
W Prated > 700 W
-6.45E-07 × P2rated + 3.80E-04 × Prated + 0.929
-3.94-08 × P2rated + 4.87E-05 × Prated + 0.974
-2.28E-09 × P2rated + 7.40E-07 × Prated + 0.990
Voltage and Frequency Independent3 0 W < Prated ≤ 300 W
300 W < Prated ≤ 700 W
Prated > 700 W
-3.13E-06 × P2rated + 1.96E-03 × Prated + 0.544
-2.60-07 × P2rated + 3.65E-04 × Prated + 0.765
-1.70E-08 × P2rated + 3.85E-05 × Prated + 0.877
  1. UPS that produces an AC output where the output voltage and frequency are dependent on the input voltage and frequency.
  2. UPS that produces an AC output that is independent of under- or over-voltage variations in the input voltage.
  3. UPS that produces an AC output voltage and frequency that is independent of input voltage and frequency variations, protecting the load from variations without depleting the internal battery.

The DOE plans to hold an in-person stakeholder meeting in Washington, DC, on September 9th, to discuss the proposed efficiency levels and the recently published UPS test procedure NOPR. A webinar will be available for those unable to attend in person. To download a copy of the efficiency NOPR (includes information on attending the meeting), click here. To download a copy of the test procedure NOPR, click here.