The Consumer Electronics Association commissioned a study
by TIAX LLC to study the power usage of consumer electronics devices. Concern about energy consumption from these devices, even when turned off, has led to calls for government standards for standby and off power consumption of electronic devices. California has set its own standards for consumer electronic equipment efficiency. Referring to the TIAX study, CEA's senior director of technology said, "This third-party study fills the information void in the energy efficiency debate. Until now, energy consumption discussions have been largely informed by limited and incomplete data from the late 1990's."
The study found that the number of CE products owned per household has approximately doubled since 1997. Active mode usage has increased for PCs, monitors and analog TV sets, but dropped slightly for compact audio equipment and DVD players. However, UEC (Unit Energy Consumption) for DVD players hasn't decreased significantly because of energy consumed in idle and off modes. The researchers were not able to provide data for DTV sets, as a standard test procedure to accurately characterize DTV active mode power draw doesn't exit, but said a DTV analysis would be completed and the findings included in an updated version of the report.
Of the 15 CE device categories tested, desktop PCs and set-top boxes with a PVR had the highest unit energy consumption, followed closely by analog TV sets. There are still more analog TV sets than PCs, so its not surprising the total annual energy consumption by analog TV sets, at 53 TWh, is more than double that of desktop PCs, at 21 TWh. The limited number of PVR set-top boxes limited their total annual energy consumption to only 0.4 TWh. All of these estimates are for 2006. The bulk of annual energy consumption is from devices operating in the active mode--68 percent, while devices in "off" mode consumed 24 percent of the estimated 147 TWh consumed by CE devices in 2006. Total consumer electronics power consumption accounted for about 11 percent of U.S. residential electricity consumption and four percent of total U.S. electricity consumption in 2006.
Per-unit off-mode power draw dropped significantly over the last seven years for compact audio, DVD player, satellite set-top box and VCR products, and to a lesser extent for analog TV sets and video games. Off-mode power consumption increased for monitors and cable set-top boxes. For PC desktops, there was little change.
The study took a look at power trends in CE products and found active mode power draw was increasing for TVs, due to growth in screen sizes; video games, due to increased processing power; and PCs, also due to increased processing power. As the PC monitor market moves to LCDs, active power consumption decreases. The study says VCR power consumption is also decreasing, probably due to technological progress. The trend for power consumption by cordless phones and set-top boxes is ambiguous. While basic unit power draw of these devices is down, increased functionality, such as answering machines and multiple handsets for cordless phones, and PVR and HD functions in set-top boxes, has increased power draw.
In addition to per unit power consumption, the number of devices and the number of hours these devices are used has to be considered. The study found that compared with previous studies (2004, 2001 and 1999) the number of active hours per year for PCs has doubled and the usage of monitors and analog TV has also increased significantly. The active hours of compact audio devices and DVD players decreased slightly.