Electronics Guide

Program Structure

The Energy Star program operates through a partnership model where manufacturers commit to producing and promoting energy-efficient products. Products must meet stringent energy efficiency specifications that are periodically updated to reflect technological improvements and maintain meaningful differentiation in the marketplace.

Key elements of the program include:

• Product specifications: Technical requirements defining minimum efficiency levels for each product category
• Third-party certification: Products must be tested and certified by EPA-recognized certification bodies
• Brand identity guidelines: Rules governing use of the Energy Star label on products and marketing materials
• Verification testing: Ongoing compliance monitoring through random product testing

Specifications are versioned, and each revision carries an effective date after which previously certified models lose their qualification unless retested against the new criteria. Because a specification revision can obsolete an entire product line's certification mid-cycle, tracking draft specifications and comment periods is as important as tracking the published ones. Energy Star also targets its criteria at roughly the top tier of the market at the time of publication, which means qualification is a moving benchmark rather than a fixed threshold.

Certification Process

Achieving Energy Star certification involves several steps:

1. Review specifications: Understand the current requirements for your product category
2. Design for efficiency: Incorporate features that will meet or exceed specification requirements
3. Select a certification body: Choose an EPA-recognized laboratory for testing
4. Submit products for testing: Provide representative samples for efficiency evaluation
5. Register products: Upon successful testing, register qualifying products in the EPA database
6. Maintain compliance: Participate in verification testing programs and update registrations as needed

Product Categories

Energy Star covers a wide range of electronics products, including:

• Computers and monitors
• Imaging equipment (printers, copiers, scanners)
• Televisions and displays
• Set-top boxes and audio/video equipment
• Enterprise servers and data storage
• Uninterruptible power supplies
• Battery charging systems
• Smart home devices

Label Design and Classes

The EU Energy Label uses a standardized format featuring a scale from A (most efficient) to G (least efficient), displayed with a color gradient from dark green to red. This intuitive design helps consumers quickly compare the relative efficiency of products.

The label underwent a significant revision that took effect on 1 March 2021, rescaling the first wave of categories (including electronic displays) from the previous A+++ to D system back to a simpler A to G format. This rescaling was necessary because technological improvements had resulted in most products clustering in the top bands of the previous scale, reducing its usefulness for differentiation. The rescaled scale is deliberately demanding: at launch, few or no products qualified for class A, leaving headroom for future efficiency gains, so most leading models were rated B, C, or D.

Rescaling continues category by category rather than in a single sweep. Household tumble dryers, for example, moved to the A to G scale on 1 July 2025, following a transition period during which both the old and new labels circulated. Manufacturers must therefore track rescaling dates per category, since a product can carry a compliant label one quarter and a non-compliant one the next.

Recent labels also carry information beyond energy use. The tumble dryer label and the label for smartphones and tablets both include a repairability class graded from A to E, signaling a deliberate shift from energy consumption alone toward broader resource efficiency.

Current product categories with energy labels include:

• Electronic displays (televisions, monitors, digital signage)
• Smartphones and slate tablets
• Household appliances (refrigerators, washing machines, dishwashers, tumble dryers)
• Light sources
• Local space heaters
• Professional refrigeration equipment

Ecodesign Directive Integration

The EU Energy Label works in conjunction with the Ecodesign Directive, which establishes mandatory minimum efficiency requirements. While the Energy Label informs consumer choice among compliant products, the Ecodesign Directive ensures that the least efficient products cannot be sold in the EU market at all.

Together, these regulations create a framework where:

• Minimum requirements eliminate the worst-performing products
• Energy labels guide consumers toward better options among compliant products
• Periodic tightening of both standards drives continuous improvement

European Product Registry (EPREL)

Manufacturers must register products in the European Product Registry for Energy Labelling (EPREL) before placing them on the EU market. This database enables:

• Market surveillance authorities to verify compliance
• Consumers to access detailed product information via QR codes on labels
• Comparison of products across the market
• Analysis of market transformation toward efficiency

Smartphones and Tablets: A Worked Example

Mobile devices are the newest major electronics category to fall under the EU framework, and they illustrate how the label and ecodesign instruments work together. Regulation (EU) 2023/1669 introduced an energy label for smartphones and slate tablets, and Regulation (EU) 2023/1670 introduced parallel ecodesign requirements. Both apply to devices placed on the EU market from 20 June 2025; models already on the market before that date are not retroactively affected.

The requirements are notable because energy efficiency is only one of several rated attributes. The label reports the device's energy efficiency class alongside battery endurance per charge cycle, a repeated free-fall reliability rating, an ingress protection rating, and a repairability class. The accompanying ecodesign rules address durability and serviceability directly:

• Batteries must retain at least 80 percent of their initial capacity after 800 full charge and discharge cycles
• Devices must withstand defined drop and scratch tests and meet a declared dust and water ingress rating
• Critical spare parts must remain available for seven years after the last unit of a model is placed on the market, with defined maximum delivery times
• Operating system security updates must be provided for a defined period after the end of placement on the market

For design teams, this pair of regulations signals where efficiency regulation is heading: a single legal framework now couples power consumption, battery lifetime, mechanical robustness, and repair logistics into one public declaration.

Label Structure

The China Energy Label uses a tiered system with Grade 1 representing the highest efficiency and Grade 5 (or Grade 3 for some categories) representing the minimum allowable efficiency. Products failing to meet minimum requirements cannot be legally sold in China.

The label displays:

• Product category
• Efficiency grade (color-coded bars)
• Key energy performance metrics
• Manufacturer and model information
• National standard reference

Covered Electronics Categories

Electronics products covered by China's energy labeling include:

• Flat panel televisions
• Computer monitors
• Printers and multifunction devices
• Projectors
• Set-top boxes
• External power supplies
• Servers and storage equipment

Compliance Process

Testing must be performed by a laboratory that the authorities recognize for the relevant national standard, in practice one accredited by the China National Accreditation Service for Conformity Assessment (CNAS). The filing process involves:

1. Testing the product to the applicable GB national standard at a recognized laboratory
2. Filing the test report and label data with the CNIS-operated China Energy Label center, which publishes the record in the national database
3. Printing and applying the label in the standardized format, including the registration number
4. Maintaining the filing as models change, and responding to market surveillance sampling

Two practical traps recur. First, the applicable GB standard is periodically tightened, and a filing made against a superseded edition becomes invalid on the new edition's effective date. Second, a grade declared on the label is a legal claim: surveillance sampling that finds a product performing below its declared grade is treated as a labeling violation, not merely a performance shortfall.

Global MEPS Programs

Major MEPS programs affecting electronics include:

• United States (federal): DOE energy conservation standards for appliances and equipment, codified in 10 CFR Part 430 and Part 431
• United States (state): California Energy Commission Appliance Efficiency Regulations, Title 20 of the California Code of Regulations, which cover battery chargers, external power supplies, computers, and monitors, and which have repeatedly set requirements ahead of federal ones
• European Union: Ecodesign implementing measures
• Australia: Greenhouse and Energy Minimum Standards (GEMS)
• South Korea: Minimum Energy Efficiency Standards Program
• Japan: Top Runner Program (performance-based approach)
• India: Bureau of Energy Efficiency Standards and Labeling Program

The design implications differ by approach. A conventional MEPS sets a fixed threshold that every model must clear. Japan's Top Runner approach instead takes the best-performing product in a category as the future target for the whole category, and applies the requirement to a manufacturer's weighted shipment average rather than to each individual model, which permits a low-efficiency model to remain on sale if the shipment mix compensates.

Harmonization Efforts

International harmonization of MEPS helps reduce compliance burden for manufacturers serving multiple markets. Organizations working toward harmonization include:

• International Energy Agency (IEA) 4E program
• International Electrotechnical Commission (IEC)
• Regional standards bodies such as APEC and ASEAN

While complete harmonization remains elusive, there is growing alignment on test methods and efficiency metrics, simplifying multi-market compliance.

Test Method Development

Energy efficiency test methods are typically developed by standards organizations such as:

• IEC: The International Electrotechnical Commission develops global standards such as IEC 62301 (measurement of standby and low-power consumption) and IEC 62087 (power measurement for audio, video, and related equipment)
• Energy Star: The EPA develops test methods for its program, often based on or aligned with IEC standards
• CENELEC: The European Committee for Electrotechnical Standardization develops EN standards, frequently adopting IEC methods as harmonized European norms
• ANSI/ASHRAE: American standards bodies that develop test procedures for commercial and HVAC equipment

Regulators commonly reference these documents directly, so a single accredited test to an IEC method can often support compliance claims across several markets.

Key Test Parameters

Typical parameters measured in electronics efficiency testing include:

• Active mode power: Power consumed during normal operation, often under defined workloads
• Idle mode power: Power consumed when connected and ready but not actively working
• Standby power: Power consumed in low-power states waiting for user activation
• Off mode power: Power consumed when switched off but still connected to power
• Power factor: Ratio of real power to apparent power
• Efficiency: Ratio of useful output to total input power

Test Conditions

Test methods specify environmental conditions and operational parameters to ensure repeatability:

• Ambient temperature (commonly 23 °C ± 5 °C, with tighter tolerances for some standby measurements)
• Relative humidity ranges
• Input voltage and frequency (may include multiple voltage conditions)
• Test pattern or workload specifications
• Warm-up and stabilization periods
• Measurement duration and data recording intervals

Standby Power Regulations

Major regulations addressing standby power include:

• EU Standby Regulation: Regulation (EU) 2023/826, which applies from 9 May 2025 and replaces the long-standing Regulation (EC) No 1275/2008. From 9 May 2025 it caps off mode and standby at 0.5 W, allowing 0.8 W where a status or information display is provided, and caps networked standby at product-specific levels ranging from about 2 W to 8 W. From 9 May 2027 the off-mode limit falls to 0.3 W and the upper end of the networked-standby range drops to about 7 W, while the 0.5 W and 0.8 W standby limits remain.
• US DOE standards: Various product-specific federal standards incorporate standby and off-mode requirements, for example for battery chargers and external power supplies
• IEA 1-watt initiative: An international goal launched to limit standby power to 1 W, now largely surpassed as 0.5 W limits have become the global norm

The 2023 regulation also widened the scope of the earlier measure, drawing in categories that were previously outside it, including battery-operated equipment and motor-operated furniture and building elements such as adjustable desks and powered blinds. Teams that assumed a product fell outside the old Regulation (EC) No 1275/2008 should re-verify scope rather than carry the earlier assessment forward.

A further practical point is the verification tolerance. EU ecodesign regulations distinguish the declared value from the value a market surveillance authority measures, and permit only a small overshoot before a product is deemed non-compliant. Designing to the exact legal limit therefore leaves no margin for unit-to-unit variation, so a target comfortably below the limit is the safer engineering choice.

Standby Mode Definitions

Understanding the different low-power modes is essential for compliance:

• Standby mode: Product is connected to power, not performing primary function, and can be switched to another mode by remote control, internal signal, or timer
• Networked standby: Product maintains network presence and can be reactivated via network signal
• Off mode: Lowest power state while connected to power; may require user action to return to operation
• Disconnected mode: No power consumption (product unplugged)

Design Strategies for Low Standby Power

Achieving low standby power requires attention throughout the design process:

• Efficient power supplies: Use switching power supplies with low no-load and light-load losses
• Power management ICs: Implement sophisticated power management to minimize quiescent current
• Component selection: Choose components with low leakage currents and efficient bias networks
• Mechanical switches: Consider true power disconnect switches for lowest standby consumption
• Wake-on-LAN optimization: Implement efficient network interface controllers for networked standby

External Power Supply Efficiency

External power supplies (EPS) are subject to specific efficiency requirements in most jurisdictions. Key standards include:

• US DOE Level VI: The mandatory federal standard for external power supplies since 2016, codified in 10 CFR 430.32 with the test method in Appendix Z. It sets both a minimum average active-mode efficiency (which scales with output power and reaches roughly 87% to 88% for many consumer supplies) and tight no-load power limits: 0.100 W for supplies rated up to 49 W, and 0.210 W for supplies rated above 49 W up to 250 W
• EU Code of Conduct on External Power Supplies: A voluntary program whose Tier 2 targets exceed mandatory minimums, often used as a stretch goal
• California Energy Commission (CEC): State appliance-efficiency requirements that have historically anticipated later federal standards

EPS active-mode efficiency is measured at four load points (25%, 50%, 75%, and 100% of rated output) and averaged. The International Efficiency Marking Protocol assigns the Roman-numeral marking (for example, the Level VI mark "VI") that appears on compliant supplies.

Internal Power Supply Efficiency

Internal power supplies in computers and servers are addressed through programs such as:

• 80 PLUS: A voluntary certification program with ascending tiers (80 PLUS, Bronze, Silver, Gold, Platinum, and Titanium). Efficiency is verified at several load points; for 115 V internal supplies, Titanium requires roughly 90% efficiency at 10% load, 92% at 20% load, 94% at 50% load, and 90% at 100% load
• Energy Star: Specifications for computers and servers effectively require 80 PLUS-class power-supply efficiency as part of their broader system requirements

System-Level Efficiency

Beyond power supply efficiency, system-level considerations include:

• Processor efficiency: Performance per watt metrics and power management capabilities
• Display efficiency: Luminance per watt and backlight technology choices
• Thermal management: Cooling system efficiency and heat recovery opportunities
• Load-proportional operation: Scaling power consumption with actual workload

Product-Level Requirements

Two instruments dominate. Commission Regulation (EU) 2019/424 sets ecodesign requirements for servers and data storage products sold in the EU, combining power supply efficiency and power factor minima, idle-state power limits, and mandatory disclosure of product information such as idle power, maximum power, and the declared operating condition class. Alongside these sit firmware and materials obligations, including the availability of the latest firmware and secure data deletion functionality.

In the United States, the Energy Star specifications for enterprise servers and data storage cover comparable ground on a voluntary basis, requiring power supplies that meet defined efficiency and power factor levels, power and temperature reporting capability, and published idle power figures.

Both approaches share a design consequence: because idle power is measured directly, a server that is efficient at full load but wasteful at rest will fail. Effective compliance depends on aggressive package and platform power states, fan control that actually reduces power at low thermal load, and a power supply that holds efficiency at the light-load end of its curve.

Facility-Level Reporting

The recast Energy Efficiency Directive, Directive (EU) 2023/1791, extends obligations beyond the equipment to the facility. Data centers with an installed information technology power demand of at least 500 kW must report energy performance and sustainability data annually into an EU database, covering indicators such as power usage effectiveness, water usage effectiveness, energy reuse factor, and renewable energy factor.

This matters to equipment vendors as well as operators. Once a customer must publish facility-level indicators, the idle power, thermal envelope, and telemetry capability of the hardware they buy become procurement criteria rather than datasheet footnotes.

Regulatory Requirements

Power factor requirements vary by market and product category:

• EU: Products above certain power thresholds must meet minimum PF requirements, typically 0.9 or higher
• Energy Star: Many specifications require a PF of 0.9 or better at the rated or test load
• 80 PLUS: Higher tiers add a power-factor criterion in addition to the efficiency targets; Titanium requires a PF of at least 0.95 at 20% load (and high power factor across the load range)

Power Factor Correction Techniques

Achieving high power factor requires active or passive correction circuitry:

• Passive PFC: Uses inductors to filter harmonic currents; simple but bulky and limited effectiveness
• Active PFC: Uses switching converters to shape input current; achieves PF above 0.99 with low harmonics
• Hybrid approaches: Combine passive filtering with active correction for cost-effective solutions

Most products requiring high power factor use active PFC based on boost converter topologies.

IEC 61000-3-2

This international standard limits harmonic current emissions from equipment with input current up to 16 A per phase. Products are classified into four categories:

• Class A: Balanced three-phase equipment, household appliances, and all other equipment not in Classes B, C, or D
• Class B: Portable tools and arc-welding equipment
• Class C: Lighting equipment
• Class D: Equipment with rated active input power of 75 W up to 600 W that draws current with a specified waveshape, principally personal computers, computer monitors, and televisions; limits below 75 W do not apply, which is why very low-power supplies need no active power-factor correction

Class D limits are expressed in milliamperes per watt of input power, so they scale with the product's power rating rather than imposing a single fixed current ceiling. Class A limits, by contrast, are absolute currents in amperes and do not scale, which means a high-power Class A product can sometimes pass with simpler input filtering than a mid-power Class D product.

A common source of confusion is the relationship between harmonics limits and power factor. They are distinct requirements measured differently: harmonic limits constrain individual current harmonic amplitudes, while power factor is an aggregate ratio. A product can achieve a respectable displacement power factor and still exceed individual harmonic limits. In practice, however, an active power factor correction stage usually resolves both at once, which is why the two requirements are so often addressed by the same circuit.

IEC 61000-3-12 and Higher-Current Equipment

Equipment drawing more than 16 A and up to 75 A per phase falls outside IEC 61000-3-2 and is instead addressed by IEC 61000-3-12. This standard limits harmonic emissions in terms of the short-circuit ratio at the point of connection, recognizing that a stiff supply tolerates more distortion than a weak one. Industrial power supplies, large uninterruptible power systems, motor drives, and electric vehicle charging equipment commonly sit in this range.

The consequence for system designers is that the applicable limit depends partly on the installation, not on the product alone. Manufacturers therefore typically declare the minimum short-circuit ratio at which the equipment complies, leaving the installer responsible for confirming that the connection point satisfies it.

Compliance Strategies

Meeting harmonics limits typically requires:

• Active PFC: Inherently produces low harmonic distortion as a side effect of current shaping
• Passive filtering: Input filters can attenuate specific harmonics
• Topology selection: Some power supply topologies inherently produce lower harmonics
• Valley-fill circuits: Cost-effective passive approach for lower power applications

Regulatory Trajectory

Expected trends in efficiency regulation include:

• Tightening limits: All major programs periodically revise specifications to capture technology improvements
• Expanded scope: New product categories are added to existing programs
• Networked standby focus: Growing attention to always-connected devices and IoT products
• Lifecycle considerations: Integration of energy efficiency with broader sustainability metrics such as durability, repairability, and recyclability, exemplified by the EU's Ecodesign for Sustainable Products Regulation (ESPR) and its forthcoming Digital Product Passport
• Smart grid integration: Requirements for demand response and grid-interactive capabilities

Technology Enablers

Emerging technologies enabling improved efficiency include:

• Wide-bandgap semiconductors: GaN and SiC devices enable higher switching frequencies and lower losses
• Advanced power management: AI-driven power management for load prediction and optimization
• Improved power supply topologies: LLC resonant converters and other advanced topologies
• Low-power processors: More efficient computing architectures for embedded applications
• Display technologies: MicroLED and advanced OLED for improved display efficiency

Preparing for Future Requirements

Manufacturers can prepare for future efficiency requirements by:

• Participating in standards development processes to understand upcoming requirements
• Designing products with efficiency headroom above current requirements
• Investing in power electronics expertise and advanced component technologies
• Implementing design-for-efficiency processes that systematically optimize power consumption
• Monitoring technology roadmaps from component suppliers

Best Practices

• Early engagement: Consider efficiency requirements from the earliest design stages
• Market analysis: Identify all applicable requirements for target markets before design freeze
• Testing partnerships: Establish relationships with qualified test laboratories
• Documentation: Maintain comprehensive records of test results, certifications, and label registrations
• Monitoring: Track regulatory developments and specification revisions
• Internal testing: Develop in-house capability for pre-compliance testing to reduce external testing iterations

Common Pitfalls

Issues that can delay market entry or create compliance problems include:

• Underestimating power consumption during product development
• Failing to account for manufacturing variation in efficiency performance
• Missing specification revision dates or new requirements
• Incorrect product classification leading to wrong test methods or limits
• Incomplete or incorrect label content
• Inadequate verification testing revealing non-compliance after market launch