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The Insatiable Power Hunger of Home Electronics
An anonymous reader writes "A Wall Street Journal columnist recently got his hand on a power meter and decided to write about his findings, the resulting article being discussed here on Slashdot. That author concluded that gadgets are getting a bad rap, and are relatively insignificant power consumers in the grand scheme of things. A rebuttal has appeared, arguing that not only are modern electronics significant power consumers already, while everything else is becoming more efficient, home electronics seem to be getting worse. This echoes the Department of Energy's assertion that 'Electricity consumption for home electronics, particularly for color TVs and computer equipment, is also forecast to grow significantly over the next two decades.' Are gadgets unfairly maligned, or getting an unearned pardon?"
In general, an LCD TV is 2x more energy efficient than a CRT. Modern dual-core processors are more energy efficient then older processors. However, as with all gains in efficiency, we're using MANY more of them. That's just what happens.
"In order to make an apple pie from scratch, you must first create the universe." -- Carl Sagan, Cosmos
I think it's more regional than anything else. The current definition of National household electricity consumption is, in effect, an average of household electricity consumption in different regions across the United States and is affected by many factors. However, hot summers increase the amount of electricity used for air conditioning and other space cooling, so households in southern States will tend to use more electricity. Similarly, cold winters increase the amount of energy used for space heating. Although U.S. households more frequently rely on natural gas than on electricity for heating, in the South the reverse is true, meaning that households in southern States will tend to have a peak of electricity use in winter as well as in summer.
Humidity is another climate-related factor that affects electricity consumption. Households in more humid regions tend to use air-conditioners and dehumidifiers to remove humidity. Households in arid regions, such as the Mountain States, are able to use evaporative coolers instead of air-conditioning for space cooling.
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Procrastination -- because good things come to those who wait.
So, who is right? The WSJ or the article referenced? Actually both.
The article referenced talks about the trends for energy consumption. And, in that respect, the consumer electronics win hands down, since more and more people buy computers, flat-screen TVs and assorted electronic gadgets. On the other hand, the WSJ is right, since the overall energy consumption of these gadgets is still a very small fraction of the total.
One thing that I'd personally like to do soon would be to compare the electricity used by all my computers (6 and counting, including a big Sun workstation, 3 laptops, a modem/router, a wireless access point, a laser printer, etc) vs the overall electricity usage in my home. I have relatively modern equipment, and I am currently switching everything to low-power equipment.
The right to offend is far more important than the right not to be offended. (Rowan Atkinson)
Sure they might run instant on feature that takes some current drain 24x7 so they can do a warm start. Or a clock.
Chase down the Off-Grid living web sites and you'll soon find that one of the biggest problems people have when they first try to do off grid is all their appliances that drain just a little power all night long, leaving insufficient power for the morning routines.
I have three digital clocks in my kitchen, two in my entertainment center... I don't own a watch anymore because I realized that there is no place except the bathroom that I can stand in my house and not see a clock face. And I don't own any clocks!
The need for everything to have a digital clock and instant on takes up a lot more power then you think. Turn everything off and go look at your meter. it's still chugging along rather nicely. We could do much better if we dropped the clocks and dropped the instant on. Tube televisions took minutes to warm up. Solid State televisions take a few seconds to warm up. Instant On only saves me 3 seconds at most.
He's absolutely right. Ignoring AC costs, IMO its house size that is causing the increase in usage, and its changes in how houses are lit. 20 years ago houses were lit typically with a single fixture in a room, and lamps. (Or, if you're in the northeast US, typically just lamps, although I couldn't tell you why that is...)
These days lighting design is all the rage, and its common to have 4 or more fixtures in a room, often R30 can lights at 65w each projecting downward so you need 4 or more to light a room. The room I'm in right now visiting my parents has 4 can lights, a light with 4 60 watt bulbs in it, and two recessed spot lights of unknown power. Ignoring those, its still 500 watts to light this room.
My house is 60+ years old, but was renovated six years ago -- most of it is can lit as well. It has 24 65 watt R30 can lights in it, among all the other lights.
I saw a nearly $30 a month drop in my electric bill switching the entire house to CFL. Dimmable R30 bulbs are pricey, $12+ each, but they will have payed themselves off in a year. I typically am facist about keeping lights off, too... I'm sure the savings would be double that if I had kids leaving them on all the time.
On a geek note, I also got a $30 savings a month by making changes in the data center in the basement. An old HP rack server was replaced with a much less power hungry desktop box which was faster... that saved 75% of the electricity it used to use. Three other desktop boxes which were slower were replaced with two free laptops with broken screens I got from friends who tend to break their laptops. The upside as well is that one small UPS can power everything for almost an hour.
On a side note, don't you just love those British 3-prong plugs? Just be careful not to step on one in the middle of the night barefoot! :-)
Or, more generally, don't step on anything pointy barefoot. Time of day and intended purpose of the pointy thing are not important.
I admit it, I now have more gadgets drawing current than I did five years ago. I have also reduced power consumption in the past five years. Five years ago, my typical electric bill was US $125 a month, it is now in the $75 range. None of the changes have caused any hardships or reduction in quality of life.
1. Replaced heat pump with a more efficient model and installed set back thermostat. I lucked out, the compressor crapped out and I had a service policy. The impact on quality of life is nil, I had to learn the new thermostat.
2. Replaced refrigerator with a more efficient model. It was expensive but the old refrigerator was about 30 years old and was reaching the end of it's service life. It is a nicer refrigerator than the old one and it is quieter.
3. Replaced commonly used light bulbs with compact fluorescent. This was an inexpensive change and it had the most impact on quality of life. The color and light quality of the new compact fluorescents compares to the old lights but they take a few minutes to produce full light output. They remind me of a tube type radio warming up.
I think that the most interesting replacements were the night lights. I replaced the 6 night lights that used to draw about 4 watts each with LEDs. I connected a wall wart to an unused wire pair in my home telephone wiring and I use the phone wiring to transport power to my night light LEDs. I had the wall wart, LEDs, and other parts in my junk box -- and they work great.
The light conversion is both saving power used for lighting and reducing the summer air conditioning load. Someday I might even figure out how long it will take to save any money by replacing those lights. The main light in the living room was a 300 watt halogen torchiere which I replaced with three fluorescent flood lights which cost $35 for a new floor lamp and bulbs, rated power consumption went from 300 watts down to about 75 watts; and I frequently don't turn on all three of the bulbs. This summer I noticed that the living room was much cooler with the new lights. The kitchen is saving a similar amount of watts but the lights in the kitchen are not used very often.
OK, here are the numbers for a mac mini (no monitor - just the cpu.)
Powered off: 0.035A
Booting: 0.250A - 0.320A
On, but idle: 0.180A - 0.250A
Sleep mode: 0.050A
Unplugged: 0.0A
So booting isn't that much more power than idle, and it's for a short period of time.
I find it interesting that powered off isn't really powered off, so you are better off using the switch on your power strip than relying on the mac "off" mode, which isn't a whole lot better than sleep.
Someone who wants to play with math more than me can figure out the break-even points, but it's clear that you are far better off unplugging your mac and rebooting overnight than leaving it in sleep mode. It's a no-brainer for a week. This basically says, unplug all your crap when you go on vacation, because with modern electronics, off isn't off.
It's true I tell you, feller at work's next door neighbour read it in the paper.
Glad you asked. The main reason is safety regulations. Devices that plug in to your household power need 3rd party certification (e.g. UL approval in US). Power supply design is a specialty, and although any EE could do it, not all can do it well, quickly and cheaply. If you (as designer) spec an external transformer, then you don't have to worry about the approval. You just buy an approved transformer and design your device to work on low voltage. This saves you thousands of dollars and many man-hours of time per design by not having to hire an independent lab to verify your safety compliance.
As an additional benefit, you can sell you product to work with different AC voltages just by supplying the appropriate transformer for each market. Plus, when you buy an external transformer, you get economies of scale because it can power not only your devices but many others built by thousands of other firms.
I am not a crackpot.
And finally, now in 2006 (in a different city), I have six things plugged in - from DVD player to the TV itself. And it is such a big mess that nobody ever unplugs anything at all - just use the remote to turn it on & off. That sleep mode does take a fair bit of power (well, tens of watts) which is just going to an absolute waste (well, heating the room).
That last bit is critical. Guys, we're not wasting ANY energy, at least during the heating season. The heat put out by the wall warts and other always-on stuff, helps heat your house. If you have electric heat, it's exactly a wash. If you heat with natural gas or propane, well, this is that much less fuel you'll burn. The cost per BTU even comes out in favor of electric, sometimes. For me, the on-peak rate is 5x as high as the off-peak rate, so during nights and weekends, electric heat is cheaper than propane.
For off-peak heating, I use a 4500W water heater, piped into plastic tubing cast into the concrete slabs in my basement and kitchen. I can get a 1 degree (f) per hour temperature rise in the slabs, which doesn't sound like much but in practice is more than enough. The electric heat, in this case, saves me quite a bit in propane costs, somewhere around 20% in heating costs savings last time I calculated.
Point is, that heat isn't wasted, unless you're running an air conditioner at the same time.