Tightening the Belt on Large Screen TV Energy Consumption

Fri, 08/31/2012 - 08:53 -- MrGreen

August 30, 2012 - Once a major component of our monthly electricity bill, big screen televisions have reduced their energy consumption over the last few years due to improvements in technology and energy efficiency programs. The U.S. EPA hopes to continue that trend by recently publishing the final draft of the next version of its ENERGY STAR television program specifications (version 6).

Key efficiency metrics in the new version include:

  • Maximum On-mode power calculation (no Automatic Brightness Control (ABC) or ABC not enabled by default)

      PON_MAX =100 × tanh(0.00085 × (Α -140) + 0.052) +14.1

      • PON_MAX is the maximum allowable On Mode Power consumption in W,
      • A is the viewable screen area of the product in square inches
      • tanh is the hyperbolic tangent function

Based on this formula, the table below shows the maximum On Mode power consumption limits for version 6 compliant TVs.

Table 1. On Mode Power Consumption Limits
  Viewable Diagonal
  Screen Size (inches)
Aspect Ratio Viewable Screen Size,
w x l (Inches)
Screen Area, A
PON_MAX (watts)
20 16:9 17.4 x 9.8 170.9 21.9
32 16:9 27.9 x 15.7 437.6 43.7
42 16:9 36.6 x 20.6 753.8 65.9
50 16:9 43.6 x 24.5 1068.2 82.7
60 16:9 52.3 x 29.4 1538.3 98.7
Source: ENERGY STAR TV program version 6 draft

As a comparison, the current ENERGY STAR TV program spec sets the maximum power consumption for a 40-inch TV at 81 W and a 60-inch TV at 108 W.

An earlier draft had incorporated a proposal for encouraging televisions with ABC enabled by default by qualifying for a 10% On Mode power allowance if they demonstrated a difference in power consumption at 10, 50, and 100 lux. In finalizing the version 6 specification, this was abandoned, reverting to the current specification, where ABC enabled TVs are qualified by measuring On Mode power at 0 lux and 300 lux. According to the EPA, one of the reasons for this decision was to avoid confusion between the test procedure currently in use and a newer test procedure being developed by the DOE.

  • Standby passive mode power consumption ≤ 1W
  • Download Acquisition Mode (DAM) energy consumption must be ≤ 0.04 kWh/day. This is a power mode where the TV is off, but is actively downloading data (i.e. channel listing information, TV setup data, or other network communications).

The EPA also plans to educate consumers that the default picture setting ("home" mode for TVs with a forced menu) reflects the setting under which the product qualified for the ENERGY STAR logo. Changing the TV's setting to a brighter performance mode could cause the set to consume higher than the ENERGY STAR power consumption limit.

If all goes as planned, the new specification will be published in the coming weeks and will become effective on May 15, 2013. Check the ENERGY STAR Television Specification pages for more information.