With the rapid expansion of the consumer electronics market, it’s clear that households will keep purchasing additional devices like home entertainment systems and network equipment, both wired and wireless. These gadgets contribute significantly to wasted standby and no-load power. Estimates suggest that the CO2 emissions from power generation account for roughly 40% of total CO2 emissions globally. Reducing electricity usage could make substantial progress in combating global warming and supporting environmental sustainability.
New research highlights that energy wastage in homes is surprisingly high, even before the first resident moves in. Designers of electrical equipment are now under immense pressure to develop more energy-efficient products, partly due to regulatory mandates. Traditionally, heating, cooling, air conditioning, lighting, and cooking were seen as the major energy hogs in homes. Regulations have since shifted toward improving thermal efficiency and insulation standards for water heaters, especially those meeting Energy Star criteria. However, energy wastage extends beyond these areas, often coming from seemingly innocuous devices that continue to draw power in standby mode.
Products like chargers (wall adapters), DVD players, set-top boxes, and TVs are prime examples of stealthy energy consumers. It’s worth emphasizing that recent governmental efforts have focused on setting strict limits for no-load and standby power consumption. Engineers designing these products need innovative solutions to comply with these regulations. To better understand the extent of energy wastage in homes, agencies are conducting multiple studies, including one by the Lawrence Berkeley National Laboratory in California. This particular study examined 13 newly built homes in California that were unoccupied at the time.
The study found that the average yearly energy consumption of these homes was 800 kWh, with nearly half of that being low-power mode consumption. On average, the standby power consumption was around 440 kWh per year, translating to approximately 50 watts of continuous standby power, even without residents! Some devices had unexpectedly high standby power usage: gas fireplaces consumed 5 watts, structured wiring boards/power supply video cameras and broadband routers consumed 20 watts, and garage door openers used 5.4 watts.
Digital TV Adapters (DTAs) exemplify how new technologies interact with government policies. By February 2009, U.S. households without cable or satellite TV would need around 30 million DTAs. Currently, the "Energy Star" program is drafting specifications requiring sleep mode power consumption to be no more than 1 watt and automatically shutting off after several hours of inactivity.
As public concern over global warming grows, regulatory bodies worldwide are tightening energy-saving standards. Certification organizations are now focusing on creating globally uniform standards rather than relying on regional or national patchworks. A notable example is the standard for external power supplies (EPS). The European Commission, CECP (China Energy Conservation Product Certification Center), Australia's GREEN Office, and KEMCO (Korea Energy Management Company) are planning to adopt the same standards as the California Energy Commission (CEC). Some institutions are transitioning from voluntary compliance to mandatory enforcement. In the U.S., many states are following California’s lead by implementing mandatory requirements.
Additionally, the EPS specification highlights another regulatory trend. Besides requiring a low-power adapter with a maximum no-load power consumption of 0.5 watts, the specification also demands an average minimum efficiency across a broad load range, as shown in Table 1 below.
| Load Condition | Minimum Efficiency Requirement (%) |
|---|---|
| No Load | ≥ 0.5 |
| Low Load | ≥ 25 |
| Medium Load | ≥ 30 |
| High Load | ≥ 35 |
For power designers, these new requirements mean that traditional design practices are no longer acceptable in terms of no-load power, standby power, and overall efficiency. In this new regulatory landscape, designers must abandon outdated methods and embrace new technologies to meet stricter demands.
Improving energy efficiency is undoubtedly challenging, but there’s good news. Recent advancements in integrated circuit technology have been remarkable. Power supplies designed with these technologies operate efficiently across the full power range while maintaining extremely low standby power consumption without additional costs. Not long ago, many power supplies—both internal and external—used linear power-frequency transformers with linear regulators. This traditional approach rarely achieved more than 50% efficiency, resulting in persistent power waste, even under no-load conditions. Furthermore, rising copper prices have diminished the cost advantage of linear power supplies. Today, almost all new designs use switching technology.
POWER Integrations is one of the leading manufacturers of power conversion ICs. In 1998, the company introduced its EcoSmart technology. Switching power supplies designed with this technology operate with higher efficiency under standby and no-load conditions. By integrating functions, the power supply no longer needs external components, reducing system costs while enhancing reliability. An IC designed with POWER Integrations’ EcoSmart technology includes a circuit that detects when the power supply is in a low-power state (no load or standby). The device then takes steps to boost efficiency in this state. It reduces the "duty cycle" by limiting power to the load and drawing less current. Additionally, it performs "cycle skipping," waiting for the device to "wake up," thus using power only intermittently. This not only reduces the average operating frequency and switching losses but also improves efficiency under low-power conditions.
Figure 1 illustrates a power supply designed with a TinySwitch-III regulator to showcase the capabilities of a new power conversion chip. With a bias winding and just three external components, the circuit’s standby consumption drops dramatically from 300 mW to 30 mW. This means saving 27 cents annually in energy costs while adding only 1 cent in component costs. Figure 2 shows how this design delivers consistent efficiency across the entire operating range, aligning with current energy efficiency regulations.
Figure 1: Standby power consumption below 30 mW with bias winding.
Figure 2: Consistent efficiency across different load modes.
The ultimate goal is to achieve "zero power consumption" in residential buildings, which could be supported by solar photovoltaic systems. While smart building designs have significantly improved energy efficiency, the rise in other energy-consuming devices like door openers and surveillance cameras presents ongoing challenges. Thus, high-efficiency switching power supplies are essential for all electronic equipment designers. Replacing linear power supplies with switching ones enables engineers to create products that easily comply with new energy-saving regulations.
UL RHW-2,Lines for Construction,UL Certified Cable, Industrial Cables Wire
Jiangyin City Weicheng Special Cable Co.,Ltd , https://www.weichengcable.com