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Energy consumption in consumer electronics

Posted: 08 Jan 2009 ?? ?Print Version ?Bookmark and Share

Keywords:consumption energy? consumer electronics?

By Rick Zarr
The Energy Zarr Blog

Zarr: I often think that with so many new devices available to consumers, the amount of energy consumed is actually growing at an ever increasing rate.

Happy New Year´with CES around the corner, it is interesting to think about consumer electronics and how energy efficient they are today. I often think that with so many new devices available to consumers, the amount of energy consumed is actually growing at an ever increasing rate. This is most likely true simply due to the decreasing cost of certain technologies. As consumers buy more, it is even more imperative that the energy efficiency of these devices continues to improve.

An interesting twist in the mix is large format flat-screen HDTVs. What most people don't realize when they rush out and buy that new 50" panel is that it probably consumes quite a bit more energy than their old 27" tube model. A 50" plasma HDTV will draw near 500 watts, where their older 27" tube model draws closer to 300 watts. With the prices of the larger displays dropping, consumers would rather have the bigger picture, than simply replace their 27" model with a similar sized LCD HDTV which actually draws far less - around 150 to 200 watts.

A similar phenomenon exists for LCD monitors for PCs. With the performance of PCs improving orders of magnitude over the last several years, gaming and other display intensive applications are now driving consumers to purchase larger LCD displays!or even multiple displays for the same PC. I'm guilty of the later since I find having multiple displays for my PC desktop provides me a larger, more efficient work-space. You've seen the stock trading setups with 6 LCD panels´I'm not quite that far yet´but it does make you think that if more monitors are hooked up to PCs, then the energy consumption!as a whole!also rises.

Speaking of PCs, they have come extremely far in energy efficiency. However, you need to look beyond the watts that flow into the machine and consider what it is doing for the energy it consumes. If you consider my first PC, which ran at 4.77 MHz, only could squeak out 0.25 MIPS for the 100 watts it consumed (not including the CRT monitor) you could calculate an efficiency rating of only 0.0025 MIPS/watt. A modern PC can exceed 1000 MIPS (considering the graphics engine as well) and may only consume 250 watts including the LCD monitor. That provides an efficiency rating of 4 MIPS/watt! an improvement of 1600 times over my PC of 28 years ago.

Also, software is very important in the efficiency equation. The operating system is well aware of the user's current processes and can greatly reduce the PC's energy consumption by various methods such as turning off hard drives, powering down LCD monitors or simply lowering the back light intensity when you're pondering your next move in game-land. All modern PCs with any energy efficiency rating tied to it will have these features.

And there is always the ubiquitous cell phone. The only problem is that you really can't call them simply a cell phone anymore. Most modern cellular phones include MP3 players, video games, calendars, contact management tools, cameras, and many more features. What's also interesting is the size of the battery!not just the capacity, but the mechanical size. I took the battery out of my Blackberry and it measures approximately 1" x 1.5" x 0.25". The old "bag" phone I used to carry in the 1980's had a battery that looked more like a lap-top pack. The lack of cell towers and early analog (AMPS) cell technology required a 3 watt transmitter in the phone which needed a big battery to provide adequate talk-time. Today, CDMA or GSM technology is far more efficient with bandwidth and power consumption. Also the mobile processors use energy saving technologies such as Adaptive Voltage Scaling pioneered by my company, National Semiconductor to further improve the efficiency of digital cores.

So to sum it up, consumer electronics have come a long way!not only in features and performance, but in their efficient use of energy. Just about every consumer electronic device or appliance carries an EnergyStar rating sticker so you know exactly how much energy the device will use. It even spells it out in dollars so you can compare equipment. With energy prices bound to rise again, most savvy consumers will look at those stickers and think about their monthly power bill before they make their purchase... till next time!

- Rick Zarr is the chief technologist of PowerWise Solutions at National Semiconductor.

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