Design Con 2015

TV manufacturers power down

-May 26, 2009

TV manufacturers have made great strides in reducing the power consumption of their products over the last couple of years. But the Environmental Protection Agency’s (EPA) Energy Star program, as well as at least one state, is pushing them to cut consumption even more.

In November 2008, Energy Star finally published a specification that set power consumption limits for TVs when they were turned on. Previous Energy Star ratings did not include limits for active power consumption because manufacturers could not agree on how to measure it fairly across all TV display technologies. Because the specification had been discussed for at least 18 months, manufacturers were well prepared.

“We saw fabulous response from manufacturers,” said Katharine Kaplan, EPA team lead, Energy Star product development. “Their 2008 lines were much less consumptive than previous versions.” Although the EPA has no formal tally, Kaplan estimates that the vast majority of TVs now on retail shelves meet the spec.

Technology tweaks reduce power
LCD TV manufacturers and their suppliers have developed several technical tweaks over the last couple of years that have helped bring down the energy consumption of their products. Among them, according to Bruce Berkoff, chairman of the LCD TV Association, are:
• Dynamic contrast or backlight control: automatically dims or turns off backlights when brightness is not needed, such as when the screen displays a dark image (a night sky, for example).
• Ambient light sensor: senses the level of the light in the room and adjusts backlighting accordingly.
• LED backlights: Not only use less power than traditional cold cathode fluorescent lamps, but also enable finer control that can further reduce power, such as dynamic contrast in specific regions of the screen.
• Fourth pixel: Instead of using only red, green, and blue pixels, the manufacturer adds a fourth, white pixel. This allows power savings because, depending on the level of brightness required, the TV can produce white by using that fourth pixel rather than a combination of red, green, and blue.
• Enhancement films: Various films can correct polarization so light, and thus power, is not wasted.

Although that sounds great, Energy Star won’t stop there. The program tries to set requirements stringent enough that only 25% of products are able to meet them. So “now we need to sharpen our pencils and drive for greater efficiency,” said Kaplan.

In late April the EPA proposed Tier 2 and Tier 3 specs. While the current requirement (Tier 1) for active power consumption is 208W, Tier 2 would lower that to 115W by May 2010 and to 81W by May 2012. (These are for a typical 42-inch screen size, regardless of technology.) In addition, the new specification would add power consumption limits for a download acquisition mode. Some of the latest TV models automatically download content, such as TV program listings, from the Internet, which uses power when the TV is presumably turned off. That amount of power exceeds the 1W limit for standby power in the Energy Star standard, so the program wants to propose a power allowance and a duration for download acquisition mode, said Kaplan.

The EPA also is adding a luminance requirement. The Tier 1 spec encouraged manufacturers to include a “forced menu.” This menu is designed to allow retailers to set the TV at its brightest setting – the “vivid” mode, which makes it look best on store shelves but also consumes more energy – while also prompting home users to turn down the brightness levels when they take it home. This “home” mode can consume 30% less energy, said Kaplan.

However, problems arose when some manufacturers set the home mode too low compared to the vivid mode. Consumers who saw a bright picture in the store would be disappointed with the home mode. They would then change back to the vivid mode, defeating Energy Star’s goal of saving power. Energy Star is trying to correct that by requiring that the home mode be set at no less than 80% of the highest luminance level.

The Consumer Electronics Association (CEA) did not officially responded to the EPA proposal by press time, but Kaplan said manufacturers are not happy about the dramatic power-consumption reduction nor the new luminance requirement. “The new spec is extremely challenging,” said Mark Sharp, group manager for the corporate environmental office of Panasonic Corp of North America. “It’s difficult for most manufacturers including Panasonic to meet in terms of our mid-sized models, anything from 26 inches to in the 50 inches.” 

Sharp points out that manufacturers have reduced power consumption by an average of 40% over the last two years. By dropping its spec to 115W, the new Energy Star proposal cuts power consumption another 50% on top of that. “We're talking about getting down to the wattage of a single light bulb for a 42-inch TV,” he said.
 
As for the luminance requirement, Sharp pointed out that the TVs will be shipped from the manufacturer set in home mode and that most consumers would not change the settings.

Total North American TV shipments in units: DisplaySearch
2007 35 million
2008 37.6 million
2009 36 million
2010 37 million

Meanwhile, TV makers are waiting to see what happens at the California Energy Commission (CEC), which has proposed energy standards for TVs sold in the state. It would require 42-inch TVs to consume 183W or less by 2011, dropping to 115.5W by 2013. Although the proposed rules would be less stringent than and go into effect later than Energy Star’s Tier 2, manufacturers have launched a full-scale campaign to try to defeat the measure. That’s because the California standard would be a requirement, whereas Energy Star is voluntary.

“On one hand, it's completely unnecessary from a policy standpoint,” said Doug Johnson, senior director of technology policy for CEA. “On the other hand, it’s seriously detrimental to the marketplace in terms of its economic impact.”

In April, CEA released a study that said CEC’s proposal would harm consumers, businesses and government tax revenues. The study, commissioned from consultant Resolutions Economics LLC, claims that the requirement would lead to higher prices on TVs as well as store closings, increased unemployment and lost tax revenues because a significant share of TV models would have to be pulled off retail shelves.

The biggest fear of TV manufacturers may be that such energy efficiency rules will spread to other states. According to Sharp, the legislatures in three other states – Washington, Maryland, and Massachusetts – have proposed similar rules, although the proposals have not been adopted.

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