Kill-a-watt

icodeboticodebot Registered Users Posts: 6
I took the advice of the moderator here to conserve first before investing in any solar equipment, and thought I'd share my results so far.

I used 768 Kwh last month. I just read my meter and compared to last months reading. In the last 27 days I'm sitting at 533 Kwh. (Hopefully I read my meter right) I only started this about 2 1/2 weeks ago in earnest. That's a pretty dramatic savings.

I spent an entire evening measuring how much power everything in my house is using with the kill-a-watt meter. It's been a good way to learn how much power I use in comparison to how much I can feasibly generate with a budget solar system.

By far my biggest savings will come from just hibernating the 3 computers in my home that normally run 24/7. They each use from 110 to 130 watts when just sitting there idle. That alone should save me $35 a month, at 20 cents a kwh.

Here is the list of things I no longer run in standby 24/7 :

300 Watts: 3 Computers running idle. (not counting monitor stand by, speakers, etc)
25 Watts: Tivo in bedroom on 24/7, which I never use.
38 Watts: Speakers, monitors, & computers now connected to easily reachable power switches. Everything switched off after hibernate mode. I tend to forget to power off the speakers, and the PSU of a computer can consume up to 8 watts even when the computer is turned off.
16 Watt: Bedroom cable box and Receiver automatically switch off with the TV by using a "smart" power strip and surge protector.
9 Watt Family Room TV, PS3, sub woofer, receiver, turned completely off when not in use with standard power strip.

That's a total of 388 watts of needless power being used when not at home and sleeping etc. If I'm good about hitting the off switches I can save almost 8 kwh a day, or 2762 kwh a year. At the cost of 20 cents a kilowatt hour that is $552 a year or $46 a month. I based this on an estimated average of 20 hours of stand by time wasted each day, and 4 hours of actual use. $46 back a month just by changing some simple wasteful habits.

Some other things I found interesting with the Kill-a-watt meter.

A typical Halogen torch lamp with a dimmer is about 200 watts at "normal" brightness and 280 watts turned all the way up. It goes down to about 28 watts at a very dim setting.

1 FIOS DVR eats 40 watt, the FIOS system needs 25 watts just to run, and the Verizon FIOS router which is not optional and must always be on is another 17 watts. So having FIOS costs me 82 watts 24/7 or $12 bucks a months to power the system.

Sony 52 Bravia LCD TV uses 245 watts while on. There is a low power setting that reduces it to 179 watts. It's a little dimmer but I'm trying it out, and it doesn't seem to bad. Maybe when I watch a good movie, I'll turn it up to full power.

My favorite bad boy energy user is the portable air conditioner in my bedroom it starts up at about 700 Watts, and slowly climbs up to 1200 watts, and draws about 11 to 12 amps. While it is switched on my average power consumptions more than doubles the norm. I haven't had to use it this year yet thankfully.

So hopefully my numbers are right, but so far it has seemed easy to save a respectable amount of energy.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    Icodebot,

    Thank you for posting your numbers/experiences...

    Sometimes I think I am a bit too optimistic when I tell people that they can save ~50% of their power bill buy just measuring with the Kill-a-Watt and turning things off (standby power, especially on older electronics, is surprisingly high)...

    Halogen lights, you will find are pretty efficient at full power (100% voltage)--however, when you dim them down, they really suck the power vs any small bulb or CFL/LED type device.

    The Portable A/C is probably a 10 SEER or less device--if you use it a lot, the 16 SEER Sanyo Mini-Split will also save you another good chunk on your A/C power usage.

    Next--lots of new insulation and double pane vinyl windows... :D

    Hope to hear more! You are saving 8kWhrs per day--that is enough to run my whole home. :cool:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    DWH,

    Yep--you are correct... The 20 SEER was for other systems (ground sourced or Fujitsu).

    Thank you and sorry.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Kill-a-watt
    BB. wrote: »
    DWH,

    Yep--you are correct... The 20 SEER was for other systems (ground sourced or Fujitsu).

    Thank you and sorry.

    -Bill

    I have absolutely no idea what you are referring to. :D


    (delete your response and then this message and no one will ever know...)
  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    DWH,

    It is OK--I have been through enough design reviews to just care about getting the product/facts right. And married long enough to not bother ever trying to win an argument. :roll:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    Just a link to Icodebot's original thread/question:

    A little discouraged

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • JeffreyDVJeffreyDV Registered Users Posts: 10
    Re: Kill-a-watt

    I have FiOS also and checked my DVR. It draws about 35 watts when idle. The router itself is turned off when not in use by using a Bye Bye Standby switch. The router is only needed for internet use, not TV or phone. The fiber optic converter must stay on 24/7, however.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Kill-a-watt

    the fiber optic converter is also a 12v item as it has a 12v battery backup on it. i haven't put my killawatt meter on it, but i don't think it would be too much power. i know it's still a phantom load as it's still on all of the time used or not and it must be on to receive phone calls.
  • icodeboticodebot Registered Users Posts: 6
    Re: Kill-a-watt
    JeffreyDV wrote: »
    I have FiOS also and checked my DVR. It draws about 35 watts when idle. The router itself is turned off when not in use by using a Bye Bye Standby switch. The router is only needed for internet use, not TV or phone. The fiber optic converter must stay on 24/7, however.


    The 5 watt difference in our measurements for the DVR may be accounted for by what the DVR was doing at the time of measurement. If it's recording 2 programs or some such it probably uses more power.

    The FIOS installer told me the router is needed for the TV channel guide information. It may cause a problem for the DVR if it doesn't have full access to the guide information. I may be wrong but I also thought it needed the router to unlock some of the premium channels. Anyway, it's not feasible for me to power off the router since someone some where in the house may be wanting to watch TV, or use the internet on one of the computers.
  • icodeboticodebot Registered Users Posts: 6
    Re: Kill-a-watt
    BB. wrote: »
    Halogen lights, you will find are pretty efficient at full power (100% voltage)--however, when you dim them down, they really suck the power vs any small bulb or CFL/LED type device.

    I have halogen MR-11 (or MR-16 not sure which) track lighting in the kitchen and the best I can think to do for now is install a power save dimmer and keep them dimmed at 80% power. They are way brighter than they need to be, and the kids leave them on all the time.

    The LED replacements are pretty pricey for that type of bulb, and I'm not too sure about the quality of light they put out compared to a halogen. I'll probably give 1 a try at some point.

    I have been changing out my bulbs to CFL, where possible. I really like the N-Vision CFL bulbs from Home Depot. I haven't found a good replacement for the candle socket, torpedo style bulbs yet.
  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    What I did was replace the "always forgotten" / most used light in the kitchen with some more energy efficient--I left the "nice looking" halogen lights there--but nobody uses them--because the wall switch is just a little bit less convenent.

    If you are also paying for A/C--that extra heat ads cost too...

    But, in the end, it is quantity of lights... If you are talking about one 5-20 watt lamp---you have other fish to fry. If there are 8x 50 watt lamps--then that is a real killer.

    In the end--I always try to prioritize and aim at the big stuff first--it keeps me (and those around me) sane. :roll:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • JeffreyDVJeffreyDV Registered Users Posts: 10
    Re: Kill-a-watt

    My kitchen has 6 MR16 halogen lights at 50 watts each. I replaced 3 with LEDs but the light isn't so great and at ~$30 a piece they are pricey.

    Put my DVR on a timer so it is only powered for about 8 hours a day. Nothing we record is on during the day and no one uses it during that time frame anyway.
  • foosmanfoosman Solar Expert Posts: 38
    Re: Kill-a-watt
    JeffreyDV wrote: »
    My kitchen has 6 MR16 halogen lights at 50 watts each. I replaced 3 with LEDs but the light isn't so great and at ~$30 a piece they are pricey.

    Put my DVR on a timer so it is only powered for about 8 hours a day. Nothing we record is on during the day and no one uses it during that time frame anyway.

    How about using room occupancy switches for the kitchen? It replaces the traditional switch and automatically turns on and off when you enter or leave the room. Legrand, Lutron and Leviton make these.
  • icodeboticodebot Registered Users Posts: 6
    Re: Kill-a-watt
    BB. wrote: »
    But, in the end, it is quantity of lights... If you are talking about one 5-20 watt lamp---you have other fish to fry. If there are 8x 50 watt lamps--then that is a real killer.

    In the end--I always try to prioritize and aim at the big stuff first--it keeps me (and those around me) sane. :roll:

    -Bill


    I had 6 50 Watt MR16s. I just replaced 3 of them today with 20 watt, the other 3 with with 35 watt. I'll probably do the dimmer at some point, but it's not as big an issue now. Really the 20 watts put out a lot of light, and I probably could have gotten away with all of them 20.
  • JeffreyDVJeffreyDV Registered Users Posts: 10
    Re: Kill-a-watt
    foosman wrote: »
    How about using room occupancy switches for the kitchen? It replaces the traditional switch and automatically turns on and off when you enter or leave the room. Legrand, Lutron and Leviton make these.

    Its funny you say that, last night I installed an occupancy sensor from Legrand. I may also try the lower wattage bulbs.
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Kill-a-watt
    icodebot wrote: »
    I had 6 50 Watt MR16s. I just replaced 3 of them today with 20 watt, the other 3 with with 35 watt. I'll probably do the dimmer at some point, but it's not as big an issue now. Really the 20 watts put out a lot of light, and I probably could have gotten away with all of them 20.

    Just thought I should mention this:

    MR16's have two main specs - wattage and beam. A lower wattage lamp with a narrower beam reflector can have a greater apparent brightness. Depending on the situation, this is sometimes a better choice than higher wattage with more spread.
  • mountaintopmountaintop Registered Users Posts: 16
    Re: Kill-a-watt

    I don’t like dimmers because they out a good amount of heat.

    In the house were getting ready to move into were going to start with all 11 watt cfls. I do have a few 18 watt bulbs on the self for the ones we find need to be brighter.
  • PeterrPeterr Registered Users Posts: 18
    Re: Kill-a-watt

    Wow, & woe is me, ;-) this Kill-a-watt meter is opening my eyes.
    Small Chest freezer was the first check... 63.15 hrs 1.14 KWH

    Next drying a lug of Peaches.. knew this one was going to go sky high, and have thought of a way to make the darn thing go solar. Six screws and the electronic heating element and fan can be set aside, with the 5 trays available for hot air. A soon project, as the tomatoes will be wanting to be dried.
    In 55.o hrs it used 7.68 KWH

    Then the old refrigerator.. jumping jahoseaphats.. still have the Kill-a-watt meter on it, going to run it for five days.. but at 55.36hrs it has used more than the dehydrator.
    So far ..55.36hrs it has used 8.30 Kwh.

    How does this compare to others who have old refrigerators?
    Hmmm.. I'm sure this has been thought of before. Can you put this thing on a timer, as an example like the DVR discussed on this thread. Perhaps at night. Have it shut off for 8 hrs. Can this be done if the seals where tight ect. We really don't have the funds right now for a new refer. Perhaps rewire the defroster, with a manual kill switch. Hmmm any thoughts..?
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Kill-a-watt

    ouch on the refrig. i have a 21cu ft refrig i bought in the early nineties and it roughly measured 1.5kwh per day during spring weather. you are more than twice what i believe you should be and some energy star refrigs today can go around 1kwh/day.
    it is possible to disable some defrosters or possibly put timers to them. maybe your defroster is stuck on or something else is amiss? just how old is it anyway?
  • PeterrPeterr Registered Users Posts: 18
    Re: Kill-a-watt

    The refer is a Kenmore 19, about 18-20 yrs old..never have had a problem with it.. Right now its running about 2+ amps.
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Kill-a-watt

    you might want to consider a new one as that one is drawing about 3x what a good energy star refrig can do. mine during normal operation(no defrost on) was around i believe 140w and that's just a bit higher than an amp. my refrig is larger, about as old, and is not an energy star.
  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    Peter,

    The good news is you are in Arizona (?). So your power is ~$0.10 per kWhr or so...

    A new fridge will be around 1-2 kWhrs per day (~400-800 kWhrs per year for a 20 cuft refrigerator/freezer).

    Say, at most, you can save 3kWhrs per day with a new fridge:

    3kWhrs * $0.10 per kWhr * 365.25 days = $110 per year

    If this fridge is in an air conditioned space, using an assumption of COP=3.5 means that it cost you about 1kWHr for every 3.5kWhr of heat you remove... Assuming you use A/C 6 months out of the year, then you would spend another:

    $110 * 1/2 year * 1kWhr/3.5kWhr = $15.70 could be saved on A/C costs with new fridge

    So--all things being equal (which they never are), you can save about $125 per year with a new Energy Star Fridge. In ~6-10 years, a new fridge would pay for itself (depending on how much you splurge).

    You can go to the website and see what the ratings of very various Energy Star appliances are:

    http://www.energystar.gov/

    Now, if you where using that much power in California--You would be looking at a $0.30 per kWhr power bill, and your savings would be on the order of 2-4 years with a new fridge.

    Also, if you have several smaller fridge/freezers (bar fridge, old fridge in garage for drinks, etc.)--Generally, you are better off combining all of those smaller storage appliances into one (or two) large ones. Looking at dorm size fridge (for example)--they are about 1/10th the size, but use about 1/2 the power--so it "costs" ~5x as much energy to keep the food in a couple of small fridges as one large one.

    -Bill

    PS: It is not only the current/power draw--it is the cycle time. Newer refrigerators tend to stay on longer, but draw less power (smaller A/C compressor).

    If you have a heater on the doors (anti-sweat for humid conditions)--some have a switch you can turn off.

    I don't think placing the fridge on a timer will help (unless you have Time of Use power metering). And disconnecting the auto defrost will force it to ice up pretty quickly (days?) and start using even more energy (I think somebody here already tried that for an off-grid / power loss situation).

    Cleaning the condenser coils (if it has them on the back or on the bottom) will help.

    -BB
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: Kill-a-watt

    disabling or timing his defroster would help tremendously as there's less humidity in az(assumption).
  • PeterrPeterr Registered Users Posts: 18
    Re: Kill-a-watt

    Hmmm.. no A/C, evap cooler, when wife insists ;-) I'm an old desert rat, but no evap during this time of year, awaiting the ..eh Monsoons... Warm and sticky.. but not like Florida or Gulf coast.. yikes.. been there done that...
    Cleaned the condenser coils in April, no extra switches to turn off... hmmm is there a way you check the seals.. a trick?

    Funny the stuff you get into.. never having even thought of it before.. it runs, its fairly quite, works, no attention and then Kill~a~watt.. enters.. slaying the peaceful obliviousness ...
  • BB.BB. Super Moderators, Administrators Posts: 29,634 admin
    Re: Kill-a-watt

    I would guess that a lot of the humidity in the refrigerator comes from the food itself (fruits, vegetables, uncovered food cooling, etc.).

    From this Drag Racer's "Tech Stop" (PDF Download)--there is about 0.015 lbs of water in humid 90F air...

    128 oz (volume) per gallon * 1/8lbs per gallon * 0.015 lbs per cuft = 2 oz of water

    Although--opening a door and exchanging a few cu.ft. of air on every opening will seem to add a fair amount of water--assuming the "modern fridge" has a fan and small evaporator--it would probably not take more than a cup or so of ice to block the airflow.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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