Chasing After Phantoms
[Warning: great big post on electrical use geekery.]
Phantom loads, that is. What am I talking about? This subject is also known as standby power, vampire power, or leaking electricity; it refers to the electric power consumed by electronic appliances while they are switched off or in a standby mode. A very common "electricity vampire" is a power adapter which has no power-off switch. Some such devices offer remote controls and digital clock features to the user, while other devices, such as power adapters for laptop computers and other electronic devices, consume power without offering any features. Here's an article from Home Energy magazine talking about the subject.
Introduction
Basically, phantom loads piss me off--they are using energy without any useful output or benefit. My boss is fond of pointing out, "I don't have a problem with using energy, I have a problem with wasting energy." Since I have an Energy Detective installed, which displays instantaneous power use (I geeked out about it previously here), I wanted to start looking into it more.
The first thing I determined was that when everything with an actual "off" switch was switched off, refrigerator not running, no lights on... there was still a continuous 90 watt load. Hrm. First of all, I wondered what that means in terms of my overall utility bill. Let's see... (90 W * 24 hours *(365 days/12 months))/1000 W (per kWh) = 65.7 kWh/month. That's about $12.50. But more importantly, looking at it on my power bill, you can see it's a fair chunk of the total ("Always on loads"):
The fridge is also a pretty noticeable portion (40-45 kWh/month)--I actually have an Energy Star fridge stored in the basement, but it's smaller than our current fridge--probably not worth the work.
I have a Kill-A-Watt electrical meter, so I guess I could go around and try to figure out what is still drawing power. But that's really annoying to do... and it only works on stuff that has a plug on it. What to do, what to do....
Work at the Panel
Duh... time to open up the circuit breaker panel, turn off everything, and measure the leakage current at each circuit. Seems kinda obvious, right?
What, you don't have a clamp-on ammeter just lying on your desk at the office?
But yeah, that was my Saturday night. Yeah, and I am still single.
Anyway, I calculated each circuit's volt-amps (same units as watts, but volt-amps != watts due to power factor. But you guys probably know that.) So, I could break down the load by circuit (go and click on the graphic if it is too small to read):
The overall wattage is pretty damn close (87.6 W, and the Energy Detective only measures to the nearest 10 W). So what are these loads?
1. Mystery breaker: 2 W of who-the-hell-knows.
3. Kitchen plug: perhaps the kitty water bubbler? Only 2 W... not worth worrying about
13. Living room outlet: this is where the cable modem, network hub, and network attached storage (NAS) are all plugged in. I'll just have to live with the 24 W (by my Kill-A-Watt measurement) continuous draw for 24/7 network access.
15. Kitchen plug: microwave oven clock--again, around 1 W
6. Living room: huh... the TV, DVD player, cable box--some of the classic vampire loads. I'll have to look into that.
8. Rear bedroom: yep, that's my bedroom. Another one to look into. But also, there are a bunch of wired smoke detectors in the house... some of the load is coming from them.
12. Boiler: well, crap... looks like I need to live with a 10-15 W draw even while the boiler is off. Suck.
16. Front bedroom: JMD's room's loads. More random phantoms.
18. Panel outlet & doorbell: again, 2 watts I'll need to live with.
Well... what to do with this information?...
Technology to the Rescue!....?
The classic way to deal with phantom loads is, "... put those loads on a power strip, and turn them off when you leave the room." Yes, yes, and we all need to floss on a daily basis, watch our carb intake, and call mom.
Yeahriiiiigh.
Anyway, there are a few technology solutions to address our natural laziness.
One problem is the fact that you typically bury the power strip at the back of the stereo cabinet, bolted to the underside of the computer desk, or hiding among the dust bunnies. Turning it off ain't gonna happen... out of sight, out of mind. But the Belkin Conserve is a power strip with a remote switch (larger pictures at that link). So the power strip stays where it is, and the switch can sit on the desk.
Second is the Smart Strip, which is a bit more complicated. A lot of the time, you have a "main load"--say, a television--and all this stuff that doesn't need power unless the TV is on--say, the cable box, or the DVD player. With this power strip, you plug in the TV into the "control outlet," and it only turns on the "automatically switched outlets" when the "control outlet" is drawing power. It also has a few "continuously on" outlets--for instance, to leave your TiVo box plugged in. Cool, eh?
Bedroom
Even with this amp-clamp-at-the-panel exercise, I wanted to check the watt draw of the various loads. So the power strip that my bedroom desktop machine is plugged into... 9 W phantom load. Seems like a good application for the Smart Strip.
Then I started measuring individual components... monitor, nothin'; stereo, almost nothin', printer, nothin'. Main CPU box, 7 watts. Crap... the one thing I'd need to leave on all the time with the SmartStrip, and it's the majority of the phantom load!
As an aside, why the hell is my desktop CPU drawing 7 watts while it is just sitting there!? According to Bird, it might have to do with network startup... um, which is entirely useless for me. Grr.
But this ended up being an application for the Belkin Conserve--the strip is on the floor, and the switch is on my desk:
9 watts, done. What's interesting is that you can calculated the financial payback--at 19 cents/kWh, that power strip has saved its purchase price in energy in 2-3 years. After all--can you name other consumer electronics that actually provides a financial return on investment?
Living Room
Time for a similar exercise in the living room--it was 9 watts, divided among the TV, the cable box, and the Blu-Ray player. Started measuring wattages... this time the cable box was the culprit, drawing 7 W while it was off. Gotcha, you sunnv'bitch...
However, I first experimented by leaving the cable box unplugged for half an hour. It turns out that it gets very unhappy--it can't download the viewer guide info, and to protest its unhappiness, it doesn't let you even change channels until it is done downloading. So I was stuck sitting there watching The Greatest Story Ever Told for ten minutes until it regained its equilibrium. Grr. That's not going to work.
So crap... no savings possible on the entertainment center.... screw yooouuuu, Motorola DCT700 box!!!
(I just thought this shot of Clyde was cute.)
Conclusions
So overall, I only managed to reduce loads by ~10 watts. But at least the TED on the kitchen table reads lower.
In my measurements, I found that more recent electronics actually do a decent job on controlling their phantom loads--a watt or less, which is not really worth pursuing, I think.
One piece of advice: you have to measure before taking steps to fix these problems. For instance, if I didn't have a Kill-A-Watt, I would have put a SmartStrip on my computer, and would currently be saving about jack-point-shit of electricity.
Finally, part of the reason why electrical loads in this country have been going up over time is that, well, we're just buying more and more gadgets to plug in. There was one letter to Fine Homebuilding that pretty much nailed it on the head for me:
The Kitchens & Baths issue (FHB #191) included a feature on warming a granite kitchen countertop, as well as a separate article on choosing energy-efficient appliances. As long as our culture is worried about cold elbows on countertops, we cannot reduce energy consumption to any appreciable degree, despite Energy Star-labeled appliances.
Ours is a gadget culture. Who can fault the architect who had the heated countertop installed? He was just pleasing his clients. I have installed a sink-top mini electric instant water heater for a customer. The blasted thing cycles continuously day and night, and is seldom used.
We don’t have to return to hunting and gathering. Our appliances enable us to store, cook, and clean up after meals safely and conveniently. However, if we want to curb energy usage, we need to have some limits on how persnickety we are.
Yeah... damn right.
posted by Bats @ 5:18 PM
12 comments
12 Comments:
It might amuse that apparently my iMac takes 2 W when it's in sleep mode. Which isn't too bad.
This is an interesting post...except, well, hm. So, suppose I could kill off 25 W of phantom load. That's, well, call it C$.05/day. It really is hard to care about that. Isn't that around the difference in changing one incandescent to a CF?
*shrug* I just wish we could get a tankless water heater. But no...
Fair enough... I think one difference here is that power rates are lower in Canada, due to the prevalence of hydroelectric power. For the non-Canadians in the audience, I was a bit thrown when I moved up there, and folks refer to the electrical utility as "hydro" (as in "How much is the hydro bill this month?").
Another part is it annoys me when phantom loads are on 24/7/365. For instance, in your example of a 25 watt load, in Massachusetts, with 19 cents/kWh electricity, that adds up to $42/year. Nope, not huge at all--a nice dinner. But not totally trivial. Enough to pay for one of those fancy power strips within a year, for whatever that's worth.
On stuff I usually only have powered up during consistent times, I've used a simple timer:
http://www.instructables.com/id/How-to-Automatically-Power-Off-Electronic-Devices/
Gah. US$.19/kWh? Wow. I'm pretty sure we're somewhere around C$.08/kWh.
(And don't over-buy into the hydro myth. There's hydro, but there's lots of coal and nuclear, too...)
(And don't over-buy into the hydro myth. There's hydro, but there's lots of coal and nuclear, too...)
Oh yeah... that reminds me of the other reason why I pursue electricity savings in particular. One is the whole "source energy" thing--3 units of energy are required at the electrical plant to create one unit of electricity at the meter--described in my electrical geekery post.
So the current power mix in Massachusetts (from Deru & Torcellini 2007):
Coal: 22%
Natural gas: 44%
Petroleum fuels: 16%
Nuclear: 12%
Hydroelectric: 2%
Renewables: 4%
I know that coal is not the biggest user here, but to me, burning coal for electricity means acid rain, mountaintop removal, sludge pond floods, and disproportionate carbon emissions:
As noted in another EIA document, "coal combustion emits almost twice as much carbon dioxide per unit of energy as does the combustion of natural gas, whereas the amount from crude oil combustion falls between coal and natural gas."
So that is interesting, in that apparently 1 barrel of oil is something like 1700 kWh. (http://www.epa.gov/grnpower/pubs/calcmeth.htm, followed by my Mac's converter...)
Which means at US$50/barrel of oil that a kWh of petroleum power should cost something like US$.03 plus whatever you pay for the cost of the plant itself, plus whatever you pay for distribution, etc.
Which makes US$.18/kWh seem crazy high, and probably makes C$.08/kWh seem crazy low, and that's the power rate for the crazy hippie power company: http://www.bullfrogpower.com/home/on_home.cfm. (Our local power company charges something like C$.06 or so, and none of these include distribution costs...)
Reminds me--I sent this out to some of my coworkers about a month ago:
Some of might be NSTAR customers, and the rest, well, I thought I'd forward it on for your information. NSTAR is offering green power (wind power from upstate New York) at a premium:
There is an additional premium for this option. Customers choosing to have 50% of their electricity support wind power pay an additional 0.837 cents per kWh, while customers choosing to have 100% of their electricity support wind power pay an additional 1.396 cents per kWh.
Wind power will be generated at Maple Ridge Wind Farm in upstate New York, before traveling into the New England power grid.
My home power bill is around 200 kWh/month, so 1.4 cents adds up to $3--definitely worth the symbolic support, for what it's worth.
So that is interesting, in that apparently 1 barrel of oil is something like 1700 kWh.
Which means at US$50/barrel of oil that a kWh of petroleum power should cost something like US$.03 plus whatever you pay for the cost of the plant itself, plus whatever you pay for distribution, etc.
Actually, I reran these numbers, and this is what I got:
1 barrel oil = 42 gallons
Fuel content of oil = 149,500 Btu/gal (residual fuel oil), or 138,700 (distillate fuel oil). Use a middling figure like 145,000 Btu/gallon
1 barrel oil = ~6 million Btu = ~1800 kWh of energy
So far so good--matches your numbers. But don't forget about the site-to-source conversion that I mentioned. So multiply the cost by a factor of three:
$50/barrel oil -> $0.03/kWh x 3 = ~$0.09/kWh
So I think that number falls more into line with what I'm talking about. Of course, coal is a much cheaper fuel. Also, it seems like this number is more in the right ballpark, based on this discussion of biomass electricity generation costs--8 cents/kWh for diesel.
Woah- Maple Ridge Wind Farm- that's 15 miles from my parents' old house. :)
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What if instead of just using the Kill-A-Watt you used the Kill-A-Watt Power Strip? Not only does it measure but also auto eliminates power.
Better than a Kill-A-Watt you could even try out the Bye Bye Standby which auto eliminates phantom power... It think that would be way more ideal.
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