EFFICIENCY STANDARDS

for external power supplies


Efficiency standards icon

Focusing on Efficiency


The global regulatory environment surrounding the legislation of external power supply efficiency and no-load power draw has rapidly evolved over the past decade since the California Energy Commission (CEC) implemented the first mandatory standard in 2004. With the United States Department of Energy (DOE) Level VI regulations that took effect in February 2016 and the European Union's Ecodesign 2019/1782 regulations that took effect in April 2020, the landscape has changed again as regulators further reduce the amount of energy that may be consumed by external power adapters. To help our customers stay on top of these continuously evolving global regulations, we have set out to push the energy efficiency initiative across our entire power portfolio. By continually monitoring the latest energy efficiency regulations, we ensure that not only our products, but our customers' products are in compliance in each region where they are sold.

Level VI Products


Level VI Products

Browse CUI's portfolio of DoE Level VI and CoC Tier 2 external ac-dc power supplies.

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A Brief History


The infographic below traces the path from the CEC's 2004 regulation, to the DoE's Level VI standards, to the EU's Ecodesign 2019/1782 requirements that went into effect on April 1st, 2020. It also shows the more stringent European Union's Code of Conduct standards that didn't become mandatory as expected, but likely show a glimpse of compulsory regulations to come.

timeline infographic for external power efficiency standards

The above timeline demonstrates just how dynamic the regulatory environment has been over the past several years. As different countries and regions enact stricter requirements and move from voluntary to mandatory programs, it has become vital that OEMs continually track the most recent developments to ensure compliance and avoid costly delays or fines.

International Efficiency Marking Protocol

The international efficiency marking protocol was designed by Energy Star/EPA in 2005. Energy Star recognized countries were creating their own standards and defined the international marking protocol in an attempt reduce confusion between standards. The marking protocol defines two performance criteria; no-load power consumption and energy efficiency. The table below summarizes the performance thresholds for each efficiency level as they were established over time.

LEVEL NO-LOAD POWER REQUIREMENT AVERAGE EFFICIENCY REQUIREMENT
I used if you do not meet any of the criteria
II ≤ 10 Watts: ≤ 0.75
> 10~250 Watts: ≤ 1.0
< 1 Watt: ≥ 0.39 x Pout
1~ < 49 Watts: ≥ 0.107 x Ln(Pout) + 0.39
> 49 Watts: 82%
III < 10 Watts: ≤ 0.5W
10~250 Watts: ≤ 0.75W
≤ 1 Watt: ≥ Power x 0.49
> 1~49 Watts: ≥ [0.09 x Ln(Power)] + 0.49
> 49~250 Watts: ≥ 84%
IV 0~250 Watts: ≤ 0.5W < 1 Watt: ≥ Power x 0.50
1~51 Watts: ≥ [0.09 x Ln(Power)] + 0.5
> 51~250 Watts: ≥ 85%
V Standard Voltage Ac-Dc Models (>6Vout)
0~49 Watts: ≤ 0.3W
50~250 Watts: ≤ 0.5W
≤ 1 Watt: ≥ 0.48 x Pout + 0.140
> 1~49 Watts: ≥ [0.0626 x Ln(Pout)] + 0.622
> 49~250 Watts: ≥ 87%
Low Voltage Ac-Dc Models (<6Vout)
0~49 Watts: ≤ 0.3W
50~250 Watts: ≤ 0.5W
≤ 1 Watt: ≥ 0.497 x Pout + 0.067
> 1~49 Watts: ≥ [0.0750 x Ln(Pout)] + 0.561
> 49~250 Watts: ≥ 86%
The term "power" means the power designated on the label of the power supply.

In 2010 Energy Star sunset their specification for external power supplies as they determined their marking should be part of the final product. After 2010 the energy star logo could no longer be used on compliant external power supplies. The international marking protocol specification was then updated by the DoE and an additional draft was produced in 2013. When the DoE drafted the Level VI efficiency standard, they extended the roman numeral marking system and introduced level “VI”.

While many countries have established voluntary programs harmonized to the international efficiency marking protocol system, the following countries and regions now have regulations in place mandating that all external power supplies shipped across their borders meet the specified efficiency level:

LEVEL COUNTRY
III Australia
VI Canada
VI United States
VI European Union

Complying with DoE Level VI


In addition to tightened regulations for existing adapters, DoE Level VI expands the range of products that fall under the standard. Regulated products now include:

  • Multiple-voltage external power supplies
  • Products with power levels > 250 watts

The performance thresholds are summarized in the tables below:

Ac-Dc External Power Supplies (except low voltage and multiple voltage output)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.5 x Pout + 0.16 ≤ 0.100
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout) - 0.0014 x Pout + 0.67 ≤ 0.100
49 W < Pout ≤ 250 W ≥ 0.880 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500
Ac-Dc Low Voltage External Power Supplies (except multiple voltage output)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.517 x Pout + 0.087 ≤ 0.100
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout) - 0.0014 x Pout + 0.609 ≤ 0.100
49 W < Pout ≤ 250 W ≥ 0.870 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500
Ac-Ac External Power Supplies (except low voltage and multiple voltage output)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.5 x Pout + 0.16 ≤ 0.210
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout) - 0.0014 x Pout + 0.67 ≤ 0.210
49 W < Pout ≤ 250 W ≥ 0.880 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500
Ac-Ac Low Voltage External Power Supplies (except multiple voltage output)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.517 x Pout + 0.087 ≤ 0.210
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout) - 0.0014 x Pout + 0.609 ≤ 0.210
49 W < Pout ≤ 250 W ≥ 0.870 ≤ 0.210
Pout > 250 W ≥ 0.875 ≤ 0.500
Multiple Output Voltage External Power Supplies
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.497 x Pout + 0.067 ≤ 0.300
1 W < Pout ≤ 49 W ≥ 0.075 x ln(Pout) + 0.561 ≤ 0.300
Pout > 49 W ≥ 0.860 ≤ 0.300

EU CoC and Ecodesign Requirements


The European Union published its Code of Conduct (CoC) on Energy Efficiency of External Power Supplies Version 5 in October 2013. With CoC Tier 1 as a voluntary requirement effective 2014 and CoC Tier 2 as a voluntary requirement effective 2016. CoC Tier 1 was expected to become mandatory in 2017 and CoC Tier 2 in 2018. However, neither CoC regulation came into force. In October 2019 the EU laid down Ecodesign regulation 2019/1782 which went into effect April 1, 2020.

With the Ecodesign 2019/1782 regulations the EU effectively harmonized with DoE Level VI and abandoned the pursuit of mandatory Tier 2 regulations in the near term. However, the voluntary CoC Tier 2 requirements may show a glimpse into the future of efficiency regulations and many speculate the inevitability of its future enforcement. The anticipation has driven many manufacturers to begin certifying their power supplies to the tighter regulations. The following overview table compares and summarizes key features between the regulations.

Regulation Efficiency Level Mandatory? 10% Load Regulations? Includes > 250 W Supplies?
DoE Level VI VI Yes No Yes
Ecodesign 2019/1782 VI Yes Measure and report but no requirements No
CoC Tier 2 More stringent than VI No Yes No

The key difference between the CoC requirements and Level VI is the new 10% load measure, which imposes efficiency requirements under a low-load condition where historically most types of power supplies have been notoriously inefficient. While the CoC regulations require certain 10% load efficiency levels be met, Ecodesign simply requires the 10% efficiency value is reported in certain cases. Another difference is neither CoC or Ecodesign have requirements for external supplies over 250 watts as DoE Level VI does.

Ecodesign 2019/1782

As the Ecodesign 2019/1872 regulation lays down energy efficiency requirements, it also introduces new information and labeling requirements. The nameplate of the power supply must include output power, output voltage, and output current information with one decimal point of precision. Instruction manuals and other relevant documentation must also include average active efficiency, efficiency at 10% load, and no-load power consumption in accordance with the legislation. The tables below detail the specific energy efficiency requirements.

Ac-Ac External Power Supplies (except low voltage and multiple voltage output)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.5 x Pout/1W+ 0.160 ≤ 0.21
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout/1W) - 0.0014 x Pout/1W+ 0.67 ≤ 0.21
49 W < Pout ≤ 250 W ≥ 0.880 ≤ 0.21
Ac-Dc External Power Supplies (except low voltage and multiple voltage output)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.5 x Pout/1W+ 0.160 ≤ 0.10
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout/1W) - 0.0014 x Pout/1W+ 0.67 ≤ 0.10
49 W < Pout ≤ 250 W ≥ 0.880 ≤ 0.21
Low Voltage External Power Supplies
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.517 x Pout/1W+ 0.087 ≤ 0.10
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout/1W) - 0.0014 x Pout/1W+ 0.609 ≤ 0.10
49 W < Pout ≤ 250 W ≥ 0.870 ≤ 0.21
Multiple Output Voltage External Power Supplies
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
Pout ≤ 1 W ≥ 0.497 x Pout/1W+ 0.067 ≤ 0.30
1 W < Pout ≤ 49 W ≥ 0.075 x ln(Pout/1W) + 0.561 ≤ 0.30
49 W < Pout ≤ 250 W ≥ 0.860 ≤ 0.30

CoC Tier 2

It is important to note that CoC did not distinguish between direct and indirect operation external power adapters. CoC Tier 2 further tightened the no-load and active mode power consumption limits for key classes of power adapters enacted by Level VI i.e. at output powers ≤49 W and 49 W < Pout ≤ 250 W and covers both standard voltage and low voltage adapters. CoC Tier 2 was scoped to cover single voltage external ac-dc and ac-ac power supplies. The tables below detail the additional requirements proposed by Tier 2.

Ac-Dc External Power Supplies (except low voltage)
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
10% Load Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
0.3 W ≤ Pout ≤ 1 W ≥ 0.50 x Pout + 0.169 ≥ 0.50 x Pout + 0.060 ≤ 0.075
1 W < Pout ≤ 49 W ≥ 0.071 x ln(Pout) - 0.00115 x Pout + 0.670 ≥ 0.071 x ln(Pout) - 0.00115 x Pout + 0.570 ≤ 0.075
49 W < Pout ≤ 250 W ≥ 0.890 ≥ 0.790 ≤ 0.150
Ac-Dc Low Voltage External Power Supplies
Nameplate Output Power (Pout) Minimum Average Efficiency in Active Mode
(expressed as a decimal)
10% Load Average Efficiency in Active Mode
(expressed as a decimal)
Maximum Power in No-Load Mode (W)
0.3 W ≤ Pout ≤ 1 W ≥ 0.517 x Pout + 0.091 ≥ 0.517 x Pout ≤ 0.075
1 W < Pout ≤ 49 W ≥ 0.0834 x ln(Pout) - 0.0011 x Pout + 0.609 ≥ 0.0834 x ln(Pout) - 0.00127 x Pout + 0.518 ≤ 0.075
49 W < Pout ≤ 250 W ≥ 0.880 ≥ 0.780 ≤ 0.150

CUI's External Ac-Dc Power Supplies


CUI is committed to implementing the latest energy saving technologies into our external power supplies to address increasing market demands and to comply with all current and future regulations. From late 2014, CUI began introducing a comprehensive DoE Level VI compliant adapter portfolio to keep our customers one step ahead of the rapidly evolving power landscape. Since then CUI has worked to ensure that the majority of its line of adapters not only meet DoE Level VI but also Ecdoesign and CoC Tier 2 standards.