International Comparison of Energy Efficiency Criteria and Test Procedures in Standards and Labeling Programs for Computer Monitors and Commercial Gas Stoves
This report presents a technical review and comparative analysis of existing and/or proposed international mandatory energy performance standards, and voluntary and mandatory energy efficiency labels and test procedures for two products — computer monitors and commercial gas stoves — being considered for revised and new minimum energy performance standards (MEPS) in China. An overview of the scope of international programs, energy efficiency and other energy-related requirements, description and detailed summary table of criteria and procedures in major test standards are presented. In addition, an estimation of potential energy savings if China were to adopt revised MEPS comparable to international levels is provided for computer monitors. A proposed methodology for estimating potential energy savings based on the European Union experience is provided for commercial gas stoves in the absence of available sales or energy consumption data.
Computer monitors labeling programs exist in the U.S. and Canada, Hong Kong and Korea and mandatory standards and categorical labeling programs have been proposed for Australia and the European Union (EU). The scope of standards and labeling (S&L) programs for monitors have been expanding over time, ranging from a narrow scope of only monitors in older voluntary labeling programs to a broader scope that includes other display products such as commercial signs and digital photo frames with similar features and performances in the newest proposed S&L programs. However, large digital displays, medical equipment displays and personal electronics and displays are excluded in all programs. In terms of efficiency metrics, all programs except Korea's e-standby label have power requirements for on-mode as well as standby- and off-modes. For on-mode power requirements, most programs calculate the maximum allowable power consumption in watts as a function of viewable screen area and resolution. The U.S. ENERGY STAR program uses different formulas for setting on-mode power requirements based on the display sizes and whether the monitor features automatic brightness control. Specifically, the recent ENERGY STAR v6.0 revision has expanded the size categories from two to five and introduced power allowances for enhanced performance and automatic brightness control. The EU Ecodesign proposal uses an energy efficiency index with a tiered approach of increasing stringency to account for expected rise in LED applications in backlit displays, and does not include additional allowances for new functionalities. Standby and off-mode power consumption limits are becoming more stringent over time as shown in proposed program requirements, decreasing from 2W standby and 1W off-mode to 0.5W for standby (and off-mode in the U.S.) and 0.3W for the most stringent off-mode requirement in the EU. Computer monitors' status as globally traded products has fostered international harmonization in the test procedures with most programs adopting the IEC test standard and/or ENERGY STAR test standard for on-mode power measurements and all programs adopting IEC 62301 for standby power measurements.
Based on this international review, regular updates of S&L programs are needed to keep pace with computer monitor's rapid rate of technological development as evidenced by the major revisions undertaken for ENERGY STAR in just over four years and the introduction of allowances to address new performance features. There is also a growing trend of grouping computer monitors with other similar products including commercial signage displays, digital photo frames, and televisions in newer standards and labeling programs. For countries such as China, key lessons learned from recent international experiences include the need for more performance measurement data collection to improve comparability across test methods, the need to address newly emerging functionalities and enhanced performances of display products through either power allowances or tiered standards approach, and the importance of test procedure harmonization. A simple stock turnover analysis shows that if China were to adopt the most stringent standby and off-mode requirements that exist today, it could save up to 1330 GWh annually by 2030. Cumulatively from 2013 to 2030, a total of 20.3 TWh to 21 TWh could be saved depending on if a one-off or tiered standard is implemented for standby in 2013 (and in 2018 for tiered approach), with the vast majority of savings from standby power reduction.
Although S&L programs have been in place for residential gas cookstoves for nearly a decade, there is currently no existing voluntary or mandatory MEPS or labeling program in the world. The EU considered adopting S&L requirements for commercial gas stoves in a 2009 Ecodesign preparatory study for cooking products but ultimately excluded it from both Ecodesign standards and EU Energy Label due to lack of reliable data, lack of suitable efficiency measurements, low sales figures and fragmented market. In the absence of any existing efficiency program for commercial gas stoves and given the similarities between household and commercial gas stoves, a review of the EU Ecodesign proposal for residential gas stoves and the recently revised U.S. MEPS for residential cooking products found very different efficiency metrics between the two programs. The U.S. only mandates that all gas cooking products not have a constant burning pilot light. The EU proposes a tiered approach with minimum gas burner efficiency being raised from 52% one year after the legislation enter into force to 65% five years after the legislation enters into force, along with standby power requirements and power management functionalities. In the absence of any harmonized international or leading test method, the U.S. and EU both use its own method for measuring gas cooktop energy consumption.
As illustrated by the few countries that considered adopting MEPS and/or labels for commercial gas stoves, data availability and the appropriate test method will be two of the major barriers facing China's standard-setting and label development process. Data collection different from that of common household or commercial energy-using products will be needed to support commercial gas stove S&L development, and the EU approach of linking commercial gas stoves to for-profit and institutional food services outlets can be considered as a starting point. In developing test procedures, the common approach of measuring efficiency by measuring the energy used to heat water in comparison to a theoretical minimum can be referenced but specific user behavior need to be considered to improve the test procedure's representativeness of real life efficiency. In the absence of any China-specific data on stock or usage of commercial gas stoves to conduct a potential savings estimate, the EU Ecodesign study is reviewed in terms of key assumptions (e.g., 12 year lifetime, existing efficiency levels of 23%-55%) and best available technologies for improvements (pot presence sensors, electronic ignition as replacement for pilot lights, gas burner design changes).