Global regulations on external power supplies and their implications

Global regulations on external power supplies and their implications

Technology News |
By eeNews Europe

So far, in the few months that have passed in 2014, the US and the EU have imposed new regulations for external power supplies. As of January, tier 1 of the EU Code of Conduct (v5) standard for external power supplies became effective. On the 10th of February, 2014, the US Department of Energy issued the final ruling on an updated external power supply standard, restricting even more the efficiency standards initially created in 2007 under the original EISA standard.

Both of these new rulings further restrict the efficiency and no-load power consumption requirements on external power supplies to the highest levels in the world. The purpose of this article is to discuss the evolution of the different power supply standards up to now, what the new rulings mean and how they impact the power supply market.

At a global level, mandates for power efficiency exist for most consumer electronics and home appliances. External power supplies have had regulations dating back to 2004, when the California Energy Commission created one of the first mandates for efficiency of external power supplies used to power appliances or consumer electronic devices. Since then, the US, European Union, China and other countries adopted both voluntary and mandatory external power supply standards as part of energy conservation legislation.

Table 1 shows a breakdown of some of the current voluntary and mandatory standards by region. Japan has a mandatory energy efficiency standard and a voluntary program called Top Runner, but neither includes an external power supply specific standard.

Table 1: Worldwide Voluntary and Mandatory External Power Supply Efficiency Standards

US – California, Energy Star and the Department of Energy
After California released its initial state regulation on external power supplies in 2004, Energy Star developed and released its first national standard for external power supplies. The specification was largely based on the original California specification, but eventually became the foundation for the first federal mandate, the Energy Independence and Security Act of 2007. The EISA 2007 act regulated all single-output external power supplies up to 250W of output power and stipulated minimum efficiency requirements for external power supplies, including standby power consumption at no load.

In February, the Department of Energy filed a final ruling on their new External Power Supply Energy Conversation standard, a significant expansion of the original EISA 2007 EPS standards. The original EISA standard had two classes of power supplies, Class A and Non-Class A power supplies. The new proposal, started originally in 2009, published in 2012 and finally ruled upon in 2014, breaks down the Class A power supplies into five new classes, with the bulk of the power supply market falling into Classes B and C. Tables 2a and 2b show a summary of the original and new class breakdowns for the Department of Energy External Power Supply regulations.

Tables 2a and 2b: Table 2a shows the EISA 2007 Classes. Table 2b shows the new Classes in the final DoE External Power Supply Energy Conservation ruling.

As part of the original specification started in 2009, the Department of Energy had included a dedicated battery charger specification, identifying 10 different battery charger classes, but this battery charger specification was removed from the final ruling. To see the full text of the final ruling, please see "Energy Conservation Standards for External Power Supplies; Final Rule."

The most obvious difference between the EISA 2007 standard and the new standard is in the no-load power consumption maximums. Tables 3a and 3b show the original Class A efficiency standards from the EISA 2007 mandate and the recently approved standard for what used to be Class A and is now divided into 4 new classes, Class B, C, D and E.

Table 3a: Minimum Efficiency and Maximum No-Load Power Consumption from EISA 2007 Standard

Table 3b: Minimum Efficiency and Maximum No-Load Power Consumption Proposal – Feb 2014 Final Ruling External Power Supplies, Classes B – E

It is immediately clear that the new standard reflects a significant decrease in the allowed standby power for most of the high-volume applications. When analyzing the load profile for the majority of Class B and Class C power supplies, they spend a large portion of their usable life in standby. By significantly reducing the maximum allowable no-load power consumption, the energy savings is substantial.

The minimum active-mode efficiency requirements also will be stricter, but the differences are not obvious without putting them into practical, real-world terms. This will be analyzed later in the article.

EU – European Commission Ecodesign and Code of Conduct Standards

The European Union is moving full steam ahead with an updated Code of Conduct, which took effect in January 2014. The EU has two different standards running in parallel, the Commission Regulation (EC) Ecodesign Directive 278/2009, which is mandatory for any product manufactured or imported for sale within the EU, and the Code of Conduct, which is a voluntary standard set at a stricter level. Tables 4a, 4b and 4c show a breakdown of the different standards and what they regulate.

Table 4a: EC278/2009 Minimum Efficiency and Maximum No-Load Power Consumption as Mandated by the EU.

Table 4b: EU CoCv4 Efficiency Requirements

Table 4c: EU CoCv5 Efficiency Requirements (Voluntary Standard, effective January 2014)

Tier 1 of version 5 of the Code of Conduct took effect in January 2014. Tier 2, not published here, is scheduled to take effect in January 2016 and has a slight, incremental increase in the efficiency levels and reduces the no-load power consumption.

There are additional data points within the Code of Conduct v5 (which are not included in these tables) that make the Code of Conduct the most expansive external power supply standard to date. Covered in these additional data points are efficiency at 10% of nameplate output power and no-load standby power for mobile battery powered applications rated at less than 8W of power. For the complete EU CoC v5 document, please see the Version 5 of the CoC EPS standards page.

Real-World Impact and Implications of the New Standards
The new standards impact both power supply manufacturers, component vendors and consumers alike. It is important to know what the differences are, the long-term benefits of these changes and what they mean to the power supply community.

Earlier, we saw the obvious differences in no-load power consumption, but the efficiency formulas in the standards don’t give that much clarity as to the active-mode efficiency differences, so the best way to understand what this actually means is to calculate some differences in minimum efficiencies comparing the current standards and the newly proposed standards.

In order to determine if a power supply meets the new proposed power supply ratings, a set of international testing standards exist to determine the efficiency of the power supply. For a power supply with a maximum rating of 10W, for example, that power supply is said to have a Nameplate Output Power of 10W. The international testing standard states to measure input power and output power at 25%, 50%, 75% and 100% loads and calculate the arithmetic average efficiency of those four points in order to determine whether or not the power supply meets the standard. Table 5 shows the actual efficiency requirements for the DoE and EU standards for four different power supply output power ratings.

Table 5: Minimum Efficiency and No-Load Requirements for Representative External Power Supplies as Regulated by Each Standard.

When you look at the results of the actual efficiency numbers by nameplate output power, the intention of the new rulemaking proposal is clear. The original efficiency standards established strict efficiency requirements for medium-high power applications (>50W). Lower power applications were allowed lower efficiency levels.

With the new proposals, efficiency targets at lighter loads are increasing in order to save energy on a broader scale. According to the Department of Energy, by increasing the efficiency requirements by the amounts shown in the new proposal, the cumulative emissions reduction from 2013 – 2042 is estimated to be 43 metric tons of CO2 and 35.5 metric tons of NOx. This is in the US alone. Similar reductions are expected in the EU with the new CoC v5 standard. This reduction in greenhouse gases results in a cumulative savings to the consumer of up to $2.7BN in just CO2 reduction alone.

Besides the reduction in greenhouse gases and their effect on the economy, the new proposal also reduces the amount of electricity that needs to be generated, and therefore also passes savings along to the consumer. By the year 2042, the annual electricity savings from the new standard and its impact on the external power supply market will be greater than 3TWh on average. When monetized, the combination of greenhouse gas reductions plus the simple energy savings by using more efficient electronics can save the consumers up to $7.5BN over a 30-year period (1).

The impact to the power supply community is also clear. The era of poor efficiency, low-cost solutions is over for the external power supply market.

The DoE, as part of their study for implementing the new standard, published a large study on the cost impact of the higher efficiency standards. According to this study, the manufacturing cost and resale price for these power supplies will increase significantly, but with the energy savings over time, the consumer will see a net benefit because of the reduced energy consumption in their home. The power supply manufacturers and power supply control IC manufacturers have the real challenge in making cost-effective power supply components that can meet both active-mode efficiency minimums while meeting the no-load power consumption mandates.

Power supply efficiency standards become stricter with each revision. International regulatory commissions strive to improve energy efficiency via strict mandates while giving the technology community time to adapt, taking into the consideration the limitations of the technology and the financial impact both to the manufacturers and the consumers. The power supply industry needs to adapt to these new standards and innovate with new technologies in order to stay ahead of the regulatory curve while keeping the cost within reach of the average consumer.



About the author
Scott Brown joined Dialog Semiconductor when it acquired iWatt in July 2013. He joined iWatt in October 2011 with over 20 years of experience in the analog semiconductor industry. Scott has broad experience in all forms of semiconductor marketing from hands-on tactical to high-level strategy and many years of experience in semiconductor business and functional management. Scott has extensive global experience and a deep knowledge of the Power Management market. Prior to iWatt Scott held marketing and management positions at National Semiconductor, Micrel, ON Semiconductor, Catalyst Semiconductor and Semtech. He holds a BSc in Electrical and Electronic Engineering from Brunel University in the UK.

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