What are the biggest energy hogs among electronics?
Contrary to common “wisdom,” it’s not data centers for the Internet and large, commercial IT operations that are the biggest energy users among electronics today, says Bruce Nordman of the Lawrence Berkeley National Laboratory.
“By my estimates, data centers are perhaps 20 percent of electronics’ energy use.” In other words, the great majority of our energy use is not in data centers, but in our buildings and homes.
Nordman has been collecting figures from various reliable sources like Tiax, which has conducted studies on energy use of electronics for the Consumer Electronics Association (CEA), and according to 2006 data, In the United States about 290 terawatt hours of electricity is used by electronics in a year.
Here’s a breakdown of what devices used what, with the numbers in terawatt hours (TWh):
37.9 TWh/year TOTAL
47.2 PC, Desktop
7.3 PC, Notebook
89.8 TWh/year TOTAL
7.3 Modem, router, etc.
21 PC, Desktop
2.8 PC, Notebook
6 Rechargeable Electronics
4.4 DVD player
1.6 Security system
51 TV, Analog
16 TV, Digital
2.3 Clock Radio
10 STB, cable
9 STB, satellite
6.2 Compact Audio
2.2 Home Theater
0.7 Portable Audio
Total 161.9 TWh/year
As you can see, electronics in the home collectively use far more electricity than that in commercial buildings and data centers. Though this is based solely on electronics usage and does not include the cooling often required in data centers.
By function, Nordman breaks down the electronics usage like this:
- Computing—35 percent
- Communication—19 percent
- Storage—4 percent
- Display—42 percent
The big display category includes TV and PC displays, though Nordman says many PC displays in general don’t use as much energy as the processors, partly because they go to sleep more often. That means our TVs are using a significant amount of juice.
Though that’s not where Nordman sees that biggest potential for energy savings. “I think the most energy can be saved in the near term in PCs,” he says. By the Lawrence Berkeley National Laboratories estimates, more than half the energy in PCs is used when no one is there and the PC is left on. The display may go to sleep, but most of us still leave our processors running. According to a recent McKinsey & Co. report, a study in 2007 showed that only 15 percent of computers in home offices had power management enabled, as manufacturers don’t necessarily enable settings at the point of sale, and consumers sometimes disable the settings.
This still doesn’t excuse consumer electronics devices. “CE networks are a mess at all layers,” says Nordman. He says that all diversity of connections and protocols make it much harder to make things connect and talk to each other. “It’s hard for devices to know what they’re connected to and make a decision on turning off,” he says. In other words, the TV is shut off, but the DVD player doesn’t know it and can play a menu for days or weeks.
Most CE devices are still in a two-state world of on or off, Nordman says. “We need to go to a three state model, where things are going to sleep.”
The Lawrence Berkeley National Laboratory is working on ways to incorporate energy-saving technologies into devices so saving energy will be easier for us. More on this later.
Follow Electronic House
Steven Castle is Electronic House's managing editor. he has been writing about consumer electronics, homes and energy efficiency topics for two decades. He is also the co-founder of GreenTech Advocates