Reproduced from e-tech, some insight into what your Plasma or LCD uses:

Reducing per model TV energy use by 25% by 2009 could save
more than 10 billion kWh per year in the US alone

By Jeanne Erdmann

Like any home appliance, televisions need energy to work. As screen size grows and picture generation evolves beyond cathode ray tubes to liquid crystal displays (LCD) and plasma, test methods that measure the amount of power consumed by flat screens need to evolve as well. A new IEC standard reflects this power consumption. The standard will also help manufacturers provide accurate energy label ratings.

A report recently issued by Displaybank, a display market research institute, shows that worldwide shipment of 101 cm (40-inch) LCD panels nearly doubled over the past year. In the same time frame, 106 cm (42-inch) panels showed a more dramatic increase of seven-fold. Jon Fairhurst of Sharp Labs of America and TC 100 project leader for 62087 says that consumer affection for large screens combined with elegant technology drive a loop of falling prices, growing supply, increased demand, and strong competition.

“We’ve been in this loop for a few years now. There are very many large TVs sold and both number and size impact power,” explains Fairhurst. “The good news is that business is good and consumers get great TVs at attractive prices, but power consumption grows.”

In turn, increased power consumption fuels a loop of higher monthly energy bills for consumers, the need for more power plants, and increased greenhouse gas emissions. Concern over power consumption brings a sense of urgency to environmental agencies and government regulators anxious for a way to obtain power measurements on LCD and plasma TVs. Reducing per model TV energy use by 25% by 2009 could save more than 10 billion kWh per year in the U.S. alone. Reducing power consumption will also decrease greenhouse gas emissions.

Without an International Standard that can quantify power consumption in LCD and plasma TVs no one could know how much energy these new screens need to generate a picture. Most important, the energy label ratings that manufacturers currently place on TVs may not be accurate. The IEC joined this effort in 2005 a few months after the National Resources Defense Council (NRDC) convened an International meeting in San Francisco to discuss the challenges of obtaining these measurements. Shortly after, Fairhurst stepped in as project leader. At the time, California had a 3% peak margin in power generation. “So if the power generation goes up by 3% they’re out of power,” says Fairhurst.

Reality TV

Picture generation draws most of the power in the display device but LCD and plasma televisions work differently and thus consume energy differently. Earlier versions of IEC 62087 incorporate several ways to measure on-mode energy using traditional three-bar methods. These static test signals worked fine for CRT-generated pictures but new technologies called for new thinking. Updating this standard to accommodate LCD and plasma flat took ingenuity and compromise.

On the ingenuity side, TC 100 members decided static was no longer suitable. They decided to incorporate moving images into the new test standard. The committee acquired video test material from the U.K., U.S., Netherlands, Australia, and Japan. Each member provided at least 40 hours of video material with an adequate mix of different genres spanning soap operas to sports. Using this target material, the project team generated a histogram that plots the average picture level of the broadcast content for these different countries. They also evaluated the brightness of the top 100 websites. Then, a software program automatically selected image segments or short clips from available content with similar average picture levels.

Reaching consensus took some energy, as well. “That was a big challenge,” says Fairhurst. But working in the IEC allowed for industry to agree on the method’s validity without the complication of any regulatory issues. “That allowed us to focus on what’s fair. We got very vocal people from both camps and we had to come up with a consensus and we were able to do that,” comment’s Fairhurst. “Working towards consensus is really what will give this standard legs.”

In the end, TC 100 produced a DVD with a 10-minute test loop of video material and 100 images representing Internet content that is to be distributed along with the IEC standard. Although the DVD may not perfectly represent each country’s national broadcast material, the average picture is more reflective of television’s performance. “Nobody watches test patterns so how can you measure the energy efficiency of TVs in use when most people don’t watch black and white horizontal stripes,” comments Matthew Armishaw Product Manager - Consumer Electronics of the UK’s Market Transformation Programme.

Quantifying energy savings

EPA EnergyStar website

TC 100 expects to issue the new standard along with the test material early in 2008. Energy Star, a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy, has distributed the DVD to a limited number of manufacturers for a restricted time frame. Energy Star sent the material only to manufacturers willing to do direct measurements and provide data to Energy Star specifically for generating Energy Star specifications. Even though this program is based in the USA, Energy Star is viewed as internationally important because it’s a voluntary program with rigid specifications rather than a government mandate.

Current labels list the maximum power requirements of a device, whether it is a TV, monitor or laptop. This is helpful for knowing how many appliances you can plug into a circuit without tripping the circuit breaker, but it doesn’t really tell you how much energy the device will consume in real world use.

The upcoming TC 100 standard will enable measurement of the average on-mode power consumption – a measure of product efficiency. By multiplying the average on-mode power consumption by the hours of use, we will now be able to estimate the total energy use of the product over time.

“This new standard gives us a way to communicate our energy efficiency. Its implementation may also help increase consumer awareness of the need to purchase electronics designed to save energy. Right now, there’s no way to really make people aware. Manufacturers can talk about power efficiency but the numbers are suspect because we don’t know how they arrived at them,” remarks David Felland of Milwaukee Public Television, and manager of TC 100’s Technical Area 1. “Now we’ll actually have some hard numbers and Energy Star’s stickers will really have an impact.”

Policy makers will eventually be able to take those numbers and generate energy-saving directives. The U.K.’s Armishaw says European policy makers are considering an energy efficiency index that examines watts per square screen centimetre or inch. Energy consumption depends on how long people watch TV over course of year. Screen size makes a difference, too. “If you look at a 32-inch TV that draws 100 watts and a 42-inch that draws 110 watts, which is the more efficient television? The new test methodology fits very well with that because allow that new step to be taken,” says Armishaw. “Theoretically this allows simple labelling for different screen sizes and technologies.” The new standard should also be flexible enough to accommodate next-generation technology, such as organic LEDs.

“This is one of those standards that might have some value to humanity. Now that’s really grand. When you start talking about all of the TVs that exists and how consumers might be able to factor this into their decision making process, that’s fairly cool,” says Felland.

 (June 2007)