Anyone interested in objective measures should consider buying a Kill-A-Watt meter. It measures power consumption of any device you can plug into it, and you can use it to calculate costs as well.
A 30-day month has 720 hours in it, so a device that consumes a constant 1000 watts of power (1 kilowatt) will use 720 kilowatt-hours of energy per month. Your utility bill should list how much you are being charged per kilowatt-hour; this is usually 10-13 cents. At 10 cents, something that uses a constant 1000 watts will cost you $72 every month.
Going down to the smaller end of the scale, a device that uses a constant 1 watt (0.001 kilowatts) would cost you $72/1000, or just 7.2 cents. While some electronic devices consume a fair bit of power in standby mode, many do not. Cell phone chargers and other “wall warts” are often accused of being energy vampires. Years ago when they were simple transformers with rectifiers, they often did consume significant power in standby mode. However, most wall-wart power supplies these days are switched-mode power supplies, which waste very little power when not supplying a device. My own cell phone charger, for example, consumes less than a watt when not charging a phone. YMMV.
For most electronic devices to qualify for an Energy Star rating, they must consume less than 2 watts in standby or “off” mode. So twenty such devices would consume a maximum of 40 watts, which is less than 15 KWH per year, which is around $1.50.
Unless it’s a non-ES-compliant wall wart that gets warm, it’s probably not worth unplugging it.
The real energy hog in most homes is the cable box/DVR, which consumes 40-150 watts 24/7, without any good way to shut it off. Typically, if you unplug it, it takes an hour or more to fully reload network and programming data, and of course can’t do any recording.
Humm~I’ve been pulling the plug that the computer(laptop) and the wireless thingboppy are hooked to… They power up and are good to go in a minute… Tv is the same… Anyway,I may not save much,but I feel like I doing something…
There are so many of those damn things in my house I could never bother futzing with them like that, crawing under tables and desks and fighting dust bunnies to get at them every time I turn an appliance on or off. What would be interesting is if I could read my energy usage live, then pull all those power adaptors and compare the use. I do have some items on power strips that I can shut the power to, but that is for groups of appliances where I want them all either on or off – my amp, PA, and effects pedals, for instance.
See post #21, re: Kill-A-Watt. It doesn’t provide a whole-house reading, but you should be able to add that up based on individual devices.
A few years ago our utility company installed a modern “smart” power meter that included a digital display and a button that lets me select different parameters for readout on that display. The other day I selected instantaneous power consumption, but found that the sum-total of all devices in the house bounces around quite a bit (possibly due to our 65" plasma TV, which exhibits image-dependent power consumption that varies anywhere between 300 and 750 watts). In that context, it would be difficult to assess the effect of unplugging a few devices that are only consuming a few watts of power.
For electronic devices, the best clue that something is an energy hog isn’t that it has a light on all the time, but that it gets warm. If you can’t buy or borrow a device to measure power usage, heat is a really good approximation.
Most cable boxes and DVRs get noticeably warm. Some of the problem is that cable companies don’t care how much you’re paying for the electricity to run their equipment, but part is that a cable box can’t tell if you’re watching TV, or (at least for some, maybe all) if the TV they’re connected to is even turned on. So they have to decode and send a signal out 24/7.
Still, if cable companies were forced to care about the electricity used by their customers, they could reduce it a lot.
Plasma TVs commonly use twice the power of an LCD model (about 120 watts vs about 60), so you might take that into account the next time you need a TV. Both generally only use significant amounts when on, though.
See Post 22. Even if AB is underestimating, you’re saving at best something like $2 or $3 a year by unplugging devices on standby such as a router or powered-down laptop. And you’ll almost certainly undo whatever little savings you make by breaking something or by misjudging your use of big power hogs like aircon.
Set your thermostat so you use heating and cooling less, especially overnight. That will dwarf just about anything else you could do.