Gadgets Getting a Free Ride?
A Wall Street Journal reporter recently did an analysis of theirhome power consumption, the resulting article making the rounds of the meme sites. Itappeared just as I was eagerly awaiting my own P3 Kill A Watt‘s arrival in the mail (no free units, or Ferrari5000 laptops, were received for that mention).
Household Power Usages
- 45W – Outside Christmas Lights
- 7W – DVD player
- 3W – Microwave sitting idle
- 785W – One Side of Toaster
- 75W – Christmas Tree Lights
- 145W – Central Vacuum Brush
- 1250W – Carpet Cleaner With Water Heater On
- 1475W – Kettle
- 995W – Coffee Maker Brew Cycle
I ordered my Kill A Watt to answer a question I posed on herelast year – “WillPower Consumption Burn Vista’s Avalon Aero Graphics?” In thatpost I pondered whether the 3D acceleration of Vista wouldmeasurably (and perhaps significantly) increase the powerconsumption of the host PC: If millions of PCs started consuming anextra 50W to power 3D interfaces, you’re into the territory ofbuilding nuclear reactors to support Windows Vista upgrades. I’llget to that later.
In his analysis, the author of the WSJ piece — Jason Fry –surveys the electricity consumption of various devices throughouthis apartment, trying to determine if gadgets are really to blamefor increasing power usage. He concludes by declaring that”gadgets don’t deserve the real blame for our nation’s mountingelectric use“.
Mr. Fry came to this conclusion after estimating that somehousehold appliances (such as a clothes dryer), along with generallighting, use ungodly amounts of electricity compared to hisobserved gadget consumption measurements.
On that point he is unarguably correct: The US DOE has beenpublishing standard power usage statistics for decades, breaking down where power goes in an average Americanhome (note: average meaning that technophileyoung households are balanced out by a large number oftechnology-free senior homes, though of course there aretech-loving seniors and tech-fearing young adults). In a recentouting the DOE found that, averaged out, refrigerators(13.7%), lighting (8%), clothes dryers (5.8%), and air conditioners(16%) were significant electricity culprits, with home electronicsseemingly minor players.
What Mr. Fry fails to observe, however, is the generaltrends in household power consumption.
Refrigeratorsand airconditioners, for instance, have seen dramatic power usageimprovements over the past couple of decades. Even a decade oldrefrigerator can be significantly less efficient than the latestmodel, gulping upwards of twice the electricity, three timesas much if it’s two decades old. Furnace blower motors have beenmoving to DC, significantly reducing their electricity consumptionas well. Even clothes dryers have seen significant efficiency improvements, not to mention that manycoffee makers are moving to a much more efficient thermal carafedesign.
On the lighting front, compact fluorescents have stormed themarket, and are now more common on retail shelves than theirobsolete incandescent predecessors, delivering the same lightwith one quarter the power.
Home insulation standards have been improving by leaps andbounds, reducing heating and cooling demands considerably: Homesmight be growing in size, but they can be heated and cooled withmuch less energy per square foot than a home of just a couple ofdecades ago, and of course lighting extra space is far cheaper.
Virtually every major appliance has seen moderate to dramaticpower improvements over the past several decades. Of course on aaverage basis some of these gains have been wiped out (from apurely per capita average perspective) as these appliances havegotten more accessible, with more homes having central air,dishwashers, and so on, but this lifestyle improvement hasthankfully come in concert with efficiency improvements.
Despite all of these improvements in the major electricalcontributors, however, the average monthly household powerconsumption has risen, as Mr. Fry notes, from793 kWh in 1990 to 938kWh in 2006.
How can we explain this seeming disparity?
The Personal Perspective
My wife and I have been slowly replacing our light bulbswith the new compact fluorescent (CF) variant ever since they firstappeared as a novelty at the local Ikea. We’ve kept buying asthey’ve gone from being bulbous, slow to turn on nuisances to beinginstant on, pleasing, low-heat, seeminglylast-forever replacements.
We’re now at the point where every single non-specialty bulb inthe house is a CF.
Outside, the CF floodlights are controlled by timers and motionsensors, and stay on for minimal durations. Inside I try to keepunused lights off, an exercise that usually necessitatescovertly following — hiding in the overly-lit shadows– behind mywife, turning off the lights she’s left on (she’s not quite ascommitted to the pursuit as I am).
Our refrigerator, clothes dryer (with moisture sensor ensuringit dries the minimal amount to achieve the job), and dishwasher(with cleanliness sensor, always run without the unnecessary drycycle) are relative new models, consuming far less electricity thantheir predecessors.
We could probably save the Earth a little more if we didn’t doone to two loads of dishes a day, and if we didn’t wash a dozenloads of laundry a week, but hey, that’s modern life with smallchildren. These are luxuries of modern living that I’m going toclutch onto until the ocean is lapping at the door.
Our air conditioner is just about to be replaced with a highefficiency SEER 16+ unit, but even that won’t make much of a dentgiven that we live in the Toronto area. While we have theoccasional hot spell, during most of the summer you can be entirelycomfortable just by intelligently opening and closing windows andshades at appropriate times (banking night time cold air can bevery effective in this pursuit). This summer past I doubt we hadthe air conditioner on for more than a half dozen days. The summerbefore was far more taxing on the AC, but the extremely high heatwas an exception…hopefully.
Our water heater is a natural gas unit, as is our furnace, thelatter having a high-efficiency DC motor.
So where’s the power going in our relatively small, suburbanhome?
Behold the power usage graph from a somewhat recent powerbill.
The months (at the bottom of the graph) go from July 2004 toJuly 2006. The summer of 2005 was freakishly hot, and our son was anewborn at the time, so we used the A/C much more than normal.
On average I’d say we use about 22kWh per day during a non A/Cday.
My main PC — the one that I’d leave on pretty much around theclock — is a rather dated affair (it’s such a pain migrating to anew PC). Featuring an Athlon 3200+, 1GB RAM, a couple of relativelysmall hard drives, and an nvidia 6600GT video card, it’sempirically relatively power efficient given that it survives quitehappily on a rather anemic 300W power supply, in an era when manyadvice guides are pushing monster 450W+ units.
This PC — the midtower alone — uses 129Wdoing nothing of consequence, with only the idle thread countingcycles for fun, spiking to 140W when it’s CPUsaturated (such as running SETI@Homearound the clock), jumping further to 165W when ademanding 3D application is running.
I often keep this PC on around the clock to allow meto access it remotely, and to make it immediately accessible when Ihave the need to jump on and do something. It is hardly uncommon inthe technology industry to have an always-on household “server” ofsorts.
Being kind (or unkind) and presuming it sits doing nothing, it’sstill eating through 3.096kWh of power per day! Doing nothing. Here inOntario that comes out to about $0.32 a day (given that thefully-priced incremental cost of electricity averages around $0.106/ kWh), but more important than the almost negligible runcost, it’s a fair amount of resources being used perhapsunnecessarily.
To try to achieve a bit more conservation, I enabled Wake-On-LANand started putting the PC in standby mode when I wasn’t using it,sure that it was yielding great savings. Imagine my surprize when Idiscovered that the so-called standby mode still slurps112W!
I thought I was saving the Earth, when actually I was justadding inconvenience for myself.
( I’ve sincediscovered that a quirk in XP had it not using the full ACPIfeatures of my system, and have since started going to S3standby, dropping the unused power consumption to a miserly5W. This is the same power consumption the systemuses when it’s “off” )
Now add in the two 19″ CRT monitors. I still use CRTsbecause they still work really well, and when purchased werehigh-end units, and still feature great display quality. I’m alsorealistic that the LCD power usage isn’t nearly as good as oftenpresumed, especially in the ultra-power backlight new units). Eachof them uses 67W when displaying a black screen,peaking at 88W with a fully white screen (LCDsgenerally don’t exhibit the same fluctuating power usage, as thebacklight is generally on all the time at full brightness, thoughsome new home theater LCD TVs can lower the brightness of thebacklight to extend the dynamic light range for very dark scenes).A comparable LCD screen would use about 45-50W(yes, I’ve validated those numbers, and a 19″ LCD really does usethat much power. There is a going myth that LCDs are far moreefficient than they really are).
Splitting the difference, that’s 77W per monitor when not in apower save mode. 154W in displays, coupled with129W+ of computer, coupled with a 5-10W speakersystem. The printer/scanner uses marginal, infrequent power, so itisn’t worth a mention.
Averaging out and very conservatively assuming that the computergets 50 hours of active use per week, 50h*(135W+154W) =14.45 kWh / week, otherwise acting as a listeningserver (118h * 129W) = 15.22 kWh / week,that accounts for a total of 29.67 kWh per week,or about 4.2 kWh per day.
19% of our power consumption going to one PC!This isn’t even my primary PC, but instead is more of the stararound which various other PCs and laptops revolve, a deploymentmodel that is appearing in many tech-savvy households.
Add to that the 5W used by the speakers, the7W used by the switch, the 10Wused by the router, all on around the clock, and this stuff startsto really add up (another 0.5 kWh per day — almost 3% ofour total daily consumption — going to a couple of unnoticedlittle devices).
20 years ago a home PC was a Commodore64 or an Atari 800, or if you were wealthy an Atari ST or justreleased Amiga. Those personal computers of the day used aroundthe same amount of power that my lowly router uses today (itself alittle computer running Linux). Now PCs are power hungry maniacs,and we often have households with multiple PCs, several on aroundthe clock.
Over the past decade the power consumption of home PCs hasincreased significantly, with brief retreats asprocessor generatures mature and see efficiency improvements. Gameentertainment units have seen the same power-hungry march, with newunits featuring massive external power bricks, often featuringfrequent heat-related crashes.
The Home Entertainment Megaplex
How about watching television Surely we’ve made great stridesin television watching.
20 years ago you’d huddle around the 23″ color television, andthat was the entirety of your “home theater”. Nowadays watchingtelevision often entails powering up the PVR, the receiver, and thebig screen television. Our own television setup is extremely modestby regional standards, and is comprised of a standard 5.1 receiver,PVR, DVD player, and 27″ LCD television. I’m going to simplifyand ignore the media PC.
Powering up the units, we see that the receiver/audio amplifiertakes 51W, regardless of output (if youreally crank it you can get it to start to spike, howeverthe difference between loud and really loud is only a W or two ofpower output, going to ear-piercing when you exceed that). Turningon the PVR we find that it takes42W. Actually it takes 42W regardless ofwhether it’s “on” or not, as it still sits there chutteringits hard drive and thinking about world domination when it’ssupposedly off. Powering on the TV, you can add another110W, despite the fact that this is a “low-power”LCD unit, with a much smaller backlight than many of the larger,ultra-high-contrast units available.
203W just to watch television.
Say that it’s on for 36 hours a week (like most families, it’soften on even when unwatched, especially given some of the greatdigital music channels our cable provider streams out), and “off”for the other 132 hours, that means that it’s consuming about 36h *(51W+42W+110W) + 132h * (42W…remember thatalways siphoning power PVR) = 7.3 kWh + 5.5 kWh = 12.8kWh, or about 1.8 kWh perday. Another 9% of our power usage goingto watching television, despite us theoretically having a lowerpower setup.
Our television power usage would be magnitudes worse if we had alarge screen plasma.
Think ahead a bit, and contemplate what the endless decline inLCD prices will result in: it seems obvious that any powerefficiency gains of LCDs over classic CRTs — an efficiencyimprovement that’s already been dwarfed by the appetiteof accessory devices in a normal home theater — will getwiped out as we move to larger and larger displays, with monsterbacklights.
It is entirely foreseeable that the near future will see aliving room with multiple screens (similar to dual or tri-monitorcomputer setups that you see today).
Discretionary Power Usage
29% of our entire household power usage going to aninfrequently used PC and the pursuit of television.
It hardly seems like gadgets are quite as innocent as Mr. Frymade them out to be. I don’t even need to add up the millions oftiny nibbles by battery chargers, accessory devices, and so on, torealize that they are a noticeable, discretionary contributorto the demand on the grid.
Fire up a PS3 on a big screen plasma and things would really getugly.
Worse still, predications are that it’s only going to get worse.The US DOE predicts that “Electricityconsumption for home electronics, particularly for color TVs andcomputer equipment, is also forecast to grow significantly over thenext two decades. EIA projects electricity consumption to grow 3.5percent annually for color TVs and computer equipment through 2025,to more than double the level of consumption in 2003.“
The Bright — Or Rather Hot — Side of PowerGluttony
Unless you’re shining lasers at alien planets, all of thatwasted energy is realized as heat: The hotter the device, themore electricity it’s consuming (and vice versa), regardless ofwhether the juice went directly and intentionally to heat– as in a stove — or as an unavoidable side effect ofsome other pursuit — such as analyzing radio signalslooking for alien chatter on your home PC (perhaps weshould combine goals and the SETI@Home people can distribute new ovenburners comprised of a grid of networked multicore processors.Win/Win!).
If you live in a hot climate, or in a moderate climateduring heat spells, all of that heat is a badthing: It means that it’s doubly wasteful, as it was wasted energyin the first place, and then is additional load on the overtaxedA/C. We’ve all experienced walking into a room hosting a PC rig tofind it unbearably hot, this computational space heater spillingout endless warmth while the rest of the house is cool.
If you live in a colder climate, however, that heat actuallycontributes to household heating, reducing the load on the mainheating supply. If you use electric heat in your household, thenall of the wasteful appliances really aren’t “wasting” duringmonths when you need to heat your home, and that PVR is just asefficient at turning 42W into heat as your baseboard would be withthe same power. This presumes that the heat isn’t excessive, and iswhere you want it.
The point is that it isn’t all loss in all situations.I can say definitively that since we’ve put more effort into beingenergy efficient in hopes of saving the planet for futuregenerations, our furnace comes on quite a bit more. Of coursenatural gas and a high efficiency furnace yield more BTUs perdollar than electricity, but it does undermine the savings just abit, and it is a pragmatic consideration to keep in mind.
Vista the Power Hog?
As mentioned at the outset, I originally ordered the Kill A Wattto get some solid numbers on whether Vista increases the powerusage of a normal PC over its predecessor.
The measured difference between doing general desktop tasks onVista Ultimate running with Aero Glass, and Windows 2003 running onthe same hardware, was negligible. I could cause powerspikes if making unreasonable demands of some of the new Vista 3Dfeatures, but could only cause a measurable difference doingsomething ridiculous with the intention of causing a spike.
Having said that, unsurprizingly some of the 3D screensaversincluded with Vista cause a 20W power consumption increase as thegraphics hardware is enlisted to help draw some spinning 3D text onthe screen (years back I worked at a small engineering shop duringa period when we proudly went from using someone’s desktop asthe “server”, upgrading to a real, albeit low-end, Dellserver. Frequently the server would seem to start choking, takingforever to perform simple tasks like transferring a file. The”sysadmin” would go up and take a look at the physical box –Windows had no real remote administration tools at the time– and declare that everything was fine. It did seem to befixed, but then twenty minutes later the sluggish response returnedyet again. The problem, as you probably guessed, was that themachine was configured to display a 3D text screensaver when not inuse: given that the machine didn’t even have hardware 3Dacceleration, the CPU was saturating doing transform and lightingcomputations for a screen saver for a box sitting in a tiny closetunseen).