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LED TV Feature Story (1): The Energy Saving Challenge of Large-Size TVs – LED TV
Nowadays, many consumers should have noticed the intense promotion campaign launched by TV vendors for LED TVs. Major Korea brand vendors have coined the term “LED TV” to promote their LCD TV models that adopt the LED backlight technology. Some TV manufacturers in Japan, China, and Europe have also followed suit and introduced a series of LED-backlit LCD TV.
In the 21st century when resources are scarce, the high energy consumption of large-size TVs has become a topic of increasing concern.
The larger the TV size, the higher the energy consumption
Typical 42inch and 50inch LCD TVs consume between 250W to 400W of electricity depending on their technical specifications. Among them, the models with 1980x 1080 resolution (or 1080P) or Full HD (high definition) feature consume more energy than ordinary HD 720P ones.
The high energy consumption of LCD TVs can be well explained by their usage of cold cathode fluorescent lamps (CCFLs) as backlight source. CCFL is similar to the commonly used fluorescent lamps, but smaller, with higher luminous efficiency. It is used to provide stable light from behind the LCD panel to ensure the image formed on the panel be shown to viewers.
Due to the obvious disadvantage of CCFL backlight, plasma TVs were favored in the market for some years for they emit light and eliminate the need for backlight.The drawback is that these TVs generate a tremendous amount of heat which also wastes energy. For this reason, as the production capability expands and technology advances in LCD TV field, the plasma TVs are losing their leading position in the market in recent years.
In light of the evolution of backlight technology for LCD TVs, will CCFL backlit LCD TVs soon be swept out of the market by LED technology?
Compared to CCFL, one of the important advantages of LED backlight is its low energy consumption. An LCD TV with LED backlight uses 50~70% less power than its CCFL-backlit alternatives of the same panel size.
New ENERGY STAR specification
U.S. Department of Energy (DOE) and Environmental Protection Agency (EPA) jointly launched the ENERGY STAR programme which requires large-size TVs to reach the new standard by May, 2010 to receive the ENERGY STAR Certification. According to ENERGY STAR Version 4.0, electrical appliances must offer at least 40% energy saving to get ENERGY STAR qualified. That means LCD TVs should be more efficient than they are now to receive the energy saving qualification.
In May, 2012, U.S. government will implement the more challenging ENERGY STAR Version 5.0, which will require the ENERGY STAR qualified TVs to offer at least 65% energy saving features.
There are reasons behind these standards the U.S. has established to promote energy saving products. According to data from the U.S. government, some 2750 million TVs are currently used in the country, which consume over 50 billion watts a year, accounting for about 4 percent of the total household electricity consumption. If saved, the power could supply all households in New York State for a whole year.
According to EPA, televisions, especially large-size TVs, consume over 4% the power used in a home, thus should be considered as energy-wasting, rather than energy-saving products. And any TV sets larger than 50inch should be regarded as resource-wasting products. EPA requires an On Mode power consumption of 108W for these TVs to get ENERGY STAR qualified. On the other hand, none of the 52inch TVs currently available on the market has met this standard, including the CCFL backlit TVs and the LED backlit products. Therefore, the overall energy saving technology must continue to evolve.
Source: EPA
According to ENERGY STAR specifications, LCD TVs larger than 50inch wouldn’t meet the energy saving standards even if they have strong energy saving features. The U.S. government estimates that more than 190 million LCD TVs larger than 40inch will enter American households in 2010, which could generate immense energy consumption if energy saving is not emphasized enough. The Version 4.0 specification requires that 46inch and 50inch TVs offer a saving of 50 percent than models currently on the market. From a market perspective, only TVs based on LED technology have the potential to be ENERGY STAR qualified under the Version 4.0 specification.
There are even more challenging regulations in the State of California. The state plans to permit only ENERGY STAR qualified large-size TVs to be sold on the market in 2011, and will further raise the standard in 2013. According to estimates by The California Energy Commission, the average overall energy consumption of DVD players, DVD recorders, cable TVs, play stations, STB and TVs accounts for around 10% the total power used in households. The State expects the amount to be reduced by 33% by 2011 when the new energy saving specification goes into effect.
In addition tothe energy saving feature, LED TVs also offer other important advantages. In the next chapter, we will explore the technical characteristics of LED TVs.
