Going from not paying electricity to paying for it, and I am rusty on the details. How to save money on my brand new hydro bill?
July 28, 2009 6:03 PM Subscribe
Going from not paying electricity to paying for it, and I am rusty on the details. How to save money on my brand new hydro bill?
Am very excited about my upcoming move! The apartment and the location are much better for me, but the rent is a little more expensive, and in addition, I am losing the gravy train of 'all-inclusive.' I have to pay for my own electricity. Water IS included, and heat is included too---giant radiators that they tell me will be TOO warm sometimes!
Appliance notes: No air conditioner or dishwasher, but I'll have two combination ceiling fan/light fixtures. I have already put in the smart bulbs. I am not sure how much energy the fan part uses, but I can turn it off and just use the light in the winter. I have a TV but will not be getting cable. I have a Macbook. I have a microwave and toaster oven. Laundry is int he basement and paid for per use via smart card (i.e. not part of my hydro bill).
Anyway, the super tells me the part of the bill I'll pay is $20-40 a month. I would like to keep it more on the $20 side, obviously. Aside from 'don't leave the light on and don't watch a lot of TV' what else can I do to keep my bill down? I am especially interested in any think outside the box ideas (less power to watch a DVD with the computer?) if you have any thoughts...
Am very excited about my upcoming move! The apartment and the location are much better for me, but the rent is a little more expensive, and in addition, I am losing the gravy train of 'all-inclusive.' I have to pay for my own electricity. Water IS included, and heat is included too---giant radiators that they tell me will be TOO warm sometimes!
Appliance notes: No air conditioner or dishwasher, but I'll have two combination ceiling fan/light fixtures. I have already put in the smart bulbs. I am not sure how much energy the fan part uses, but I can turn it off and just use the light in the winter. I have a TV but will not be getting cable. I have a Macbook. I have a microwave and toaster oven. Laundry is int he basement and paid for per use via smart card (i.e. not part of my hydro bill).
Anyway, the super tells me the part of the bill I'll pay is $20-40 a month. I would like to keep it more on the $20 side, obviously. Aside from 'don't leave the light on and don't watch a lot of TV' what else can I do to keep my bill down? I am especially interested in any think outside the box ideas (less power to watch a DVD with the computer?) if you have any thoughts...
Well, you COULD put in a small generator and use the free water to produce more electricity. Or, more realistically, you can be careful about the lights, turn of your computer when not using it, and buy a Kill-a-Watt to see how much individual appliances use.
Is your stove/oven gas or electric? If it's electric, try to use the toaster oven instead of the oven when plausible. How about your water heater? If it's electric (and you have one for your apartment rather than for your building), take quick showers, etc.
posted by JMOZ at 6:17 PM on July 28, 2009
Is your stove/oven gas or electric? If it's electric, try to use the toaster oven instead of the oven when plausible. How about your water heater? If it's electric (and you have one for your apartment rather than for your building), take quick showers, etc.
posted by JMOZ at 6:17 PM on July 28, 2009
If the fridge is 20 or 30 years old, it could account for most of the electricity bill. But they've become more efficient lately. if it's 3 to 5 years old, it might only cost $20 a year.
Electric stoves are more efficient than they used to be too. In our old place, when we replaced the fridge and stove, it cut our hydro bill in half. Don't know if you have any influence on replacing appliances, but if you do then that would be something to push for (if they're old).
Getting a kill-a-watt is a good idea if you're serious about tracking down your electricity usage.
posted by winston at 6:24 PM on July 28, 2009
Electric stoves are more efficient than they used to be too. In our old place, when we replaced the fridge and stove, it cut our hydro bill in half. Don't know if you have any influence on replacing appliances, but if you do then that would be something to push for (if they're old).
Getting a kill-a-watt is a good idea if you're serious about tracking down your electricity usage.
posted by winston at 6:24 PM on July 28, 2009
my library (ottawa) has kill-a-watts for checkout.
posted by betsybetsy at 6:25 PM on July 28, 2009
posted by betsybetsy at 6:25 PM on July 28, 2009
I don't have much in the way of suggestions because I'm currently in the utilities-included category. However, starting in mid-August I will be in a situation very similar to yours and I'm not looking forward to my first bill (so I will definitely be keeping an eye on this thread)!
One thing that I have heard that works pretty well is to unplug everything when you leave the house. I've heard/read that this is much easier to do if you plug stuff into surge protectors and then just turn off/unplug those.
posted by Nolechick11 at 6:26 PM on July 28, 2009
One thing that I have heard that works pretty well is to unplug everything when you leave the house. I've heard/read that this is much easier to do if you plug stuff into surge protectors and then just turn off/unplug those.
posted by Nolechick11 at 6:26 PM on July 28, 2009
For most people, the three biggest uses of electricity are electric heat, electric hot water heaters, and refrigerators. Sounds like you're getting heat and hot water from other sources, so your frig is going to be your big user.
Unfortunately, there isn't really a whole lot you can do about how much power your frig uses. Turn the temp up, so it doesn't run as much, but that's not a huge difference. And from the sound of it, your frig is probably going to be about half your total.
Things like changing your light bulbs may make you feel good, but they'll have little effect on your bill. Over ten hours of use, a CFL may save you 5¢ over an incandescent bulb. (And since CFLs are more expensive, they can take years to pay for themselves.)
There are obvious things you can do, like not burn lights when you don't need them, but the gains from that will be very small. There isn't anything easy and miraculous you can do which will cut your bill in half.
Except to unplug your refrigerator. That'd do it.
posted by Chocolate Pickle at 6:27 PM on July 28, 2009
Unfortunately, there isn't really a whole lot you can do about how much power your frig uses. Turn the temp up, so it doesn't run as much, but that's not a huge difference. And from the sound of it, your frig is probably going to be about half your total.
Things like changing your light bulbs may make you feel good, but they'll have little effect on your bill. Over ten hours of use, a CFL may save you 5¢ over an incandescent bulb. (And since CFLs are more expensive, they can take years to pay for themselves.)
There are obvious things you can do, like not burn lights when you don't need them, but the gains from that will be very small. There isn't anything easy and miraculous you can do which will cut your bill in half.
Except to unplug your refrigerator. That'd do it.
posted by Chocolate Pickle at 6:27 PM on July 28, 2009
...the super tells me the part of the bill I'll pay is $20-40 a month.
Um, the part of the bill? Does that mean that the building gets one combined bill, and the super will ask you for a portion of it?
If so, and unless you're actually getting your own bill from the electric company, nothing you do is going to matter much.
If they can't isolate "your" usage, then you'll just be reducing everyone's bill, and the savings will be spread across all tenants. Amounting to, like, $10 divided by the number of payers.
(Not that it's good to save energy in general, Earth-wise, but it might not save you any money.)
posted by rokusan at 6:37 PM on July 28, 2009 [1 favorite]
Um, the part of the bill? Does that mean that the building gets one combined bill, and the super will ask you for a portion of it?
If so, and unless you're actually getting your own bill from the electric company, nothing you do is going to matter much.
If they can't isolate "your" usage, then you'll just be reducing everyone's bill, and the savings will be spread across all tenants. Amounting to, like, $10 divided by the number of payers.
(Not that it's good to save energy in general, Earth-wise, but it might not save you any money.)
posted by rokusan at 6:37 PM on July 28, 2009 [1 favorite]
Things like changing your light bulbs may make you feel good, but they'll have little effect on your bill. Over ten hours of use, a CFL may save you 5¢ over an incandescent bulb. (And since CFLs are more expensive, they can take years to pay for themselves.)
Sorry, but I call bullshit. How long will that kind of myth be perpetuated? Yes, it's pennies per day per bulb, but those nickels add up. Change the bulbs. Here's the math:
Say you're good about keeping lights turned off and you get by with 6 bulbs used 5 hours a day on average, at 60 watts each. That consumes 1800 watt-hours (6 x 5 x 30) or 1.8 kilowatt hours. At 15 cents a KWH, that costs you 27 cents, daily. With compact fluorescents, each bulb draws 13 watts, and your daily use goes to 390 watt-hours (6 x 5 x16) or .39 KWH, costing 5.85 cents per day. You save 21.15 cents daily, or $77.20 per year (equivalent to 2 to 3 months of electric bills at the landlord's estimate). The bulbs are often subsidized by the electric company at 99 cents or $1.99 each, but even if they cost 5-6 bucks the payback is vey quick. If you think you'll move relatively soon and they're in the landlord's fixtures, save the old incandescants and put them back in when you move out.
If your bill is somehow shared with other apartments in the building, show them the math and get everybody to change their bulbs.
posted by beagle at 7:02 PM on July 28, 2009
Sorry, but I call bullshit. How long will that kind of myth be perpetuated? Yes, it's pennies per day per bulb, but those nickels add up. Change the bulbs. Here's the math:
Say you're good about keeping lights turned off and you get by with 6 bulbs used 5 hours a day on average, at 60 watts each. That consumes 1800 watt-hours (6 x 5 x 30) or 1.8 kilowatt hours. At 15 cents a KWH, that costs you 27 cents, daily. With compact fluorescents, each bulb draws 13 watts, and your daily use goes to 390 watt-hours (6 x 5 x16) or .39 KWH, costing 5.85 cents per day. You save 21.15 cents daily, or $77.20 per year (equivalent to 2 to 3 months of electric bills at the landlord's estimate). The bulbs are often subsidized by the electric company at 99 cents or $1.99 each, but even if they cost 5-6 bucks the payback is vey quick. If you think you'll move relatively soon and they're in the landlord's fixtures, save the old incandescants and put them back in when you move out.
If your bill is somehow shared with other apartments in the building, show them the math and get everybody to change their bulbs.
posted by beagle at 7:02 PM on July 28, 2009
Good catch by rokusan - is your unit individually metered or are you paying a fixed % of the building?
Old appliances suck a lot of energy, I hate hate hate the fridge that came with my apartment. Old clothing dryers are hogs, too.
To pinch pennies, make sure that your TV and monitors and other electronics that - when you turn them off (or turn the computer off) - are truly turned off. Lots of TVs go into "standby" mode and while "off" will still draw power. Monitors, even if when you turn the computer off, may look like they're off, but will still draw power. Modern versions are more efficient, but it adds up. There are ways to completely turn them off, check you the manuals or play around with it.
Of course, you know to turn lights off when you don't need them; not to keep the fridge door open gaping open, &c. Most fridges, though, can be set to different temperatures. I actually keep (the knobs are 1-4 and 1-10; I throw a thermometer in there to see what the actual temp is) my decrepit old fridge at about 10-12'C instead of the 4'C it's "supposed" to be at and I've had no problems. I don't keep a lot of takeout food in there, but home-made leftovers are good for at least 3 days and up to 5 or 7. My freezer's at closer to -10'C than -20'C but it has been fine.
/worried about my next hydro bill; bought an AC 2 months ago and suffering from a heat wave for the last couple of weeks
posted by porpoise at 7:16 PM on July 28, 2009
Old appliances suck a lot of energy, I hate hate hate the fridge that came with my apartment. Old clothing dryers are hogs, too.
To pinch pennies, make sure that your TV and monitors and other electronics that - when you turn them off (or turn the computer off) - are truly turned off. Lots of TVs go into "standby" mode and while "off" will still draw power. Monitors, even if when you turn the computer off, may look like they're off, but will still draw power. Modern versions are more efficient, but it adds up. There are ways to completely turn them off, check you the manuals or play around with it.
Of course, you know to turn lights off when you don't need them; not to keep the fridge door open gaping open, &c. Most fridges, though, can be set to different temperatures. I actually keep (the knobs are 1-4 and 1-10; I throw a thermometer in there to see what the actual temp is) my decrepit old fridge at about 10-12'C instead of the 4'C it's "supposed" to be at and I've had no problems. I don't keep a lot of takeout food in there, but home-made leftovers are good for at least 3 days and up to 5 or 7. My freezer's at closer to -10'C than -20'C but it has been fine.
/worried about my next hydro bill; bought an AC 2 months ago and suffering from a heat wave for the last couple of weeks
posted by porpoise at 7:16 PM on July 28, 2009
Sorry to tell you, but many ceiling fan motors, especially older ones with 2 or 3 switchable speeds, and a direction reversing switch, are really inefficient. The problem is, in order to get several speeds, and reverse action, on 110 volt single phase AC power, the fan designers often built those things around something called a squirrel cage rotor. Because of magnetic eddy currents in the windings of motors of that design, they rarely achieve high efficiency, unless made with very high quality copper windings, plenty of magnet material, and enough iron to prevent saturation in slip mode operation. Because of weight and size considerations for ceiling fans, and the desire to have those motors run as silently as possible, electrical efficiency was often sacrificed in their design.
Anytime you run those kind of motors, in each revolution, they have to pull more energy from the line than they require to do actual work, simply to form their magnetic fields of operation, and they then quickly return this excess power, later in the same revolution, to the electrical line. But, since the power company has to size its generators and distribution equipment to deliver the instantaneous power demanded of them, you pay for this power, which does no real work (and which is thus referred to as imaginary power or reactive power), except to create and collapse the ever changing magnetic fields of the motor phases. In other terms, these kinds of motors are said to have poor power factor.
The bottom line is, each of those motors can wind up using about what your refrigerator takes to operate, in terms of average hourly power consumption. So, don't use those ceiling fans, unless you absolutely must.
posted by paulsc at 7:25 PM on July 28, 2009
Anytime you run those kind of motors, in each revolution, they have to pull more energy from the line than they require to do actual work, simply to form their magnetic fields of operation, and they then quickly return this excess power, later in the same revolution, to the electrical line. But, since the power company has to size its generators and distribution equipment to deliver the instantaneous power demanded of them, you pay for this power, which does no real work (and which is thus referred to as imaginary power or reactive power), except to create and collapse the ever changing magnetic fields of the motor phases. In other terms, these kinds of motors are said to have poor power factor.
The bottom line is, each of those motors can wind up using about what your refrigerator takes to operate, in terms of average hourly power consumption. So, don't use those ceiling fans, unless you absolutely must.
posted by paulsc at 7:25 PM on July 28, 2009
Keeping your fridge full of stuff will reduce its power consumption a little. I like beer, but I suppose you could do it with bottles of water.
Also, charge your macbook at work.
posted by pompomtom at 8:01 PM on July 28, 2009
Also, charge your macbook at work.
posted by pompomtom at 8:01 PM on July 28, 2009
paulsc: Anytime you run those kind of motors, in each revolution, they have to pull more energy from the line than they require to do actual work, simply to form their magnetic fields of operation, and they then quickly return this excess power, later in the same revolution, to the electrical line. But, since the power company has to size its generators and distribution equipment to deliver the instantaneous power demanded of them, you pay for this power, which does no real work (and which is thus referred to as imaginary power or reactive power), except to create and collapse the ever changing magnetic fields of the motor phases. In other terms, these kinds of motors are said to have poor power factor.
This is kinda, sorta correct but confuses a few things. You only pay the power company for real power, not reactive power. Induction motors are actually rather efficient although they do have power factor issues. But it is the power company that takes a loss on the resistive losses due to unmetered reactive power, not the user. That is why the power company requires power factor correction for factories with large inductive loads.
A typical ceiling fan will use 75 to 100 watts.
posted by JackFlash at 10:10 PM on July 28, 2009
This is kinda, sorta correct but confuses a few things. You only pay the power company for real power, not reactive power. Induction motors are actually rather efficient although they do have power factor issues. But it is the power company that takes a loss on the resistive losses due to unmetered reactive power, not the user. That is why the power company requires power factor correction for factories with large inductive loads.
A typical ceiling fan will use 75 to 100 watts.
posted by JackFlash at 10:10 PM on July 28, 2009
Also I have heard it helps to keep you refrigerator/freezer stuffed, as the solids hold their temperature better than air.
posted by psycho-alchemy at 11:13 PM on July 28, 2009
posted by psycho-alchemy at 11:13 PM on July 28, 2009
"... That is why the power company requires power factor correction for factories with large inductive loads. ..."
That's kinda, sorta not the way it works, JackFlash. If the power company cares at all about your power factor at a large industrial site, it's because you've got such a tremendously large inductive or capacitive load, that they are having problems supplying power to you, or more probably, to other clients on your sub-system, that conforms to reasonable approximations of a sine wave. They are getting complaints of poor voltage regulation, RF noise, and/or equipment failures at adjacent customer sites, and they are looking to fix those issues, pronto. Their choice then, is often to massively upgrade their transformers or distribution network, and continue to charge you for phantom reactive power, or to get you to improve your power factor, by adding capacitors, or inductors, as needed to bring your use closer to a pure resistive load's profile. They can generally prevail upon you to do so, at lower cost to you, because the correction equipment on your end is cheaper than the additional capacity equipment on their end, and because you recover money in energy savings, for improving your power factor.
It's only been in the last 20 years or so, as utilities have gotten to higher and higher levels of utilization, that anybody has cared much care about power factor correction. With the cost of additional pollution controls, and fuel costs, adding generation and distribution capacity to serve customers with large reactive power demands has become a losing game, financially, for most power companies. Hence, the occasional emphasis on power factor correction for individual large industrial clients.
But this is all moot for our friend, the new apartment tenant. There is little she can do, that is economic, to improve the efficiency of her ceiling fans, except to use them, as little as possible, and to be aware of their costs of operation, when she does. If she has small diameter, say 36", perhaps 3 blade fans, her fan motors may be smaller than mine, and use less power. Or, if her fans are the most modern, energy saving designs, so much the better, and she can temper my previous advice, with small, early experimental runs, and a look at her resulting hydro bills.
But, while I don't know about your ceiling fans, JackFlash, mine, down here in Florida, which are 52" diameter, about 12 years old, can use up to 240 watts on their high speed settings, by their sticker ratings (I got out my step stool and magnifying glass, and checked!). That's about 1/3 horsepower, on a big 5 blade fan, without the included lights on, or about a third the power a vacuum cleaner uses. What's different is that a vacuum cleaner, or a refrigerator, or most other appliances, only run for a relatively short amount of time, in a given time period. Whereas, a ceiling fan is often run for hours, sucking up the real and imaginary power it requires, the whole time. Run constantly, for 12 hours, on high speed, a big ceiling fan can easily use more power than a refrigerator uses in 24 hours.
And more is my word to the wise, if our OP, the new tenant, has 3 or 4 such fans, and desires to use them all, on hot days. In which case, the additive power use of all those fan motors is very likely to make her refrigerator's power draw look like a candle in the window, even before she turns on any of the fan lights!
posted by paulsc at 11:15 PM on July 28, 2009
That's kinda, sorta not the way it works, JackFlash. If the power company cares at all about your power factor at a large industrial site, it's because you've got such a tremendously large inductive or capacitive load, that they are having problems supplying power to you, or more probably, to other clients on your sub-system, that conforms to reasonable approximations of a sine wave. They are getting complaints of poor voltage regulation, RF noise, and/or equipment failures at adjacent customer sites, and they are looking to fix those issues, pronto. Their choice then, is often to massively upgrade their transformers or distribution network, and continue to charge you for phantom reactive power, or to get you to improve your power factor, by adding capacitors, or inductors, as needed to bring your use closer to a pure resistive load's profile. They can generally prevail upon you to do so, at lower cost to you, because the correction equipment on your end is cheaper than the additional capacity equipment on their end, and because you recover money in energy savings, for improving your power factor.
It's only been in the last 20 years or so, as utilities have gotten to higher and higher levels of utilization, that anybody has cared much care about power factor correction. With the cost of additional pollution controls, and fuel costs, adding generation and distribution capacity to serve customers with large reactive power demands has become a losing game, financially, for most power companies. Hence, the occasional emphasis on power factor correction for individual large industrial clients.
But this is all moot for our friend, the new apartment tenant. There is little she can do, that is economic, to improve the efficiency of her ceiling fans, except to use them, as little as possible, and to be aware of their costs of operation, when she does. If she has small diameter, say 36", perhaps 3 blade fans, her fan motors may be smaller than mine, and use less power. Or, if her fans are the most modern, energy saving designs, so much the better, and she can temper my previous advice, with small, early experimental runs, and a look at her resulting hydro bills.
But, while I don't know about your ceiling fans, JackFlash, mine, down here in Florida, which are 52" diameter, about 12 years old, can use up to 240 watts on their high speed settings, by their sticker ratings (I got out my step stool and magnifying glass, and checked!). That's about 1/3 horsepower, on a big 5 blade fan, without the included lights on, or about a third the power a vacuum cleaner uses. What's different is that a vacuum cleaner, or a refrigerator, or most other appliances, only run for a relatively short amount of time, in a given time period. Whereas, a ceiling fan is often run for hours, sucking up the real and imaginary power it requires, the whole time. Run constantly, for 12 hours, on high speed, a big ceiling fan can easily use more power than a refrigerator uses in 24 hours.
And more is my word to the wise, if our OP, the new tenant, has 3 or 4 such fans, and desires to use them all, on hot days. In which case, the additive power use of all those fan motors is very likely to make her refrigerator's power draw look like a candle in the window, even before she turns on any of the fan lights!
posted by paulsc at 11:15 PM on July 28, 2009
Paulsc, this is a fundamental point -- a power meter measures watts not VA. It measures real power, not apparent power. You can change the reactive load of your house and it affects your meter reading and power bill not at all. This seems to be where you got off track.
Read this from your own link: Power factor
Power factor correction is not a new phenomena (as you claim), it has been around since the beginning of power distribution and power companies have always cared about it because it affects their profits. Factories with, say, a few thousand horsepower of inductive motors are either charged a tariff or required to install banks of power factor correction capacitors. Sometimes synchronous motors, which look like capacitors, were used to offset the effect of the inductive motors. Power substations very commonly have power factor correction capacitors. This isn't something that just appeared in the last 20 years. It's always been there.
The efficiency of a motor does not depend on its power factor (to a first order approximation) because the user is not billed for reactive power. The power company bears the burden of greater generation and transmission requirements due to a poor power factor, not the user. Motor efficiency is calculated using watts, not VA, so reactive power doesn't even enter the equation. There are lots of things that determine the efficiency of a motor (amount of copper, type of steel, thinness of stator laminations, geometry of the core, etc) but power factor is not one of them.
All the OP cares about is how many watts are used by their ceiling fan. Power factor correction does not benefit the user because a poor power factor doesn't cost them anything, (unless they are an industrial user subject to tariff). The power factor is completely irrelevant.
posted by JackFlash at 12:48 AM on July 29, 2009
Read this from your own link: Power factor
Power factor correction is not a new phenomena (as you claim), it has been around since the beginning of power distribution and power companies have always cared about it because it affects their profits. Factories with, say, a few thousand horsepower of inductive motors are either charged a tariff or required to install banks of power factor correction capacitors. Sometimes synchronous motors, which look like capacitors, were used to offset the effect of the inductive motors. Power substations very commonly have power factor correction capacitors. This isn't something that just appeared in the last 20 years. It's always been there.
The efficiency of a motor does not depend on its power factor (to a first order approximation) because the user is not billed for reactive power. The power company bears the burden of greater generation and transmission requirements due to a poor power factor, not the user. Motor efficiency is calculated using watts, not VA, so reactive power doesn't even enter the equation. There are lots of things that determine the efficiency of a motor (amount of copper, type of steel, thinness of stator laminations, geometry of the core, etc) but power factor is not one of them.
All the OP cares about is how many watts are used by their ceiling fan. Power factor correction does not benefit the user because a poor power factor doesn't cost them anything, (unless they are an industrial user subject to tariff). The power factor is completely irrelevant.
posted by JackFlash at 12:48 AM on July 29, 2009
"... Power factor correction does not benefit the user because a poor power factor doesn't cost them anything, (unless they are an industrial user subject to tariff). The power factor is completely irrelevant."
posted by JackFlash at 3:48 AM on July 29 [+] [!]
Power factor is not completely irrelevant, JackFlash, even for a residential user. The losses due to poor power factor have just generally not been economically worth correcting, as this article demonstrates. Basically, for a single 1 HP motor at a .75 inductive PF, the cost of that motor's poor power factor vs. a purely resistive load, depending on the number of hours run, can be from $0.06 a month to $0.18 per month, even at a paltry $0.10/kwh cost for power, for appliances that run only a comparatively few hours per month, as the right hand column of this table demonstrates.
But for fans, which might run many hours per month, at worse power factors, there is a real, calculable cost for poor power factor, which most assuredly, a residential user will pay, even if it is just pennies per day, per motor. And that is just a delta cost, over the larger cost for the real power consumed by those fans, in pushing air around, and wasting up to 1/3 of the real power they do draw as resistive heat in their windings, if their motors are as inefficient in operation as are many older squirrel cage designs.
But things are slowly changing on the design front, for consumer electronics and appliances, and that is one reason that organizations like 80 Plus have developed specifications and designs for high power factor power supplies in consumer devices like computers, TVs and entertainment electronics, which now provide power factor correction internally through improved electronics, getting to power factors of .9, when a few years ago, such devices often ran at .6 power factor. And in the long run, more efficient choices designs in all appliances, with due regard for construction costs, keeps down utility rates, by helping utilities avoid new plant construction, and expensive peak hour generation.
But, as I said orginally, there is little that makes economic sense to do for the OP, other than to be aware of the potential costs some ceiling fans can create on the user's hydro bill, and to use them judiciously.
posted by paulsc at 2:38 AM on July 29, 2009
posted by JackFlash at 3:48 AM on July 29 [+] [!]
Power factor is not completely irrelevant, JackFlash, even for a residential user. The losses due to poor power factor have just generally not been economically worth correcting, as this article demonstrates. Basically, for a single 1 HP motor at a .75 inductive PF, the cost of that motor's poor power factor vs. a purely resistive load, depending on the number of hours run, can be from $0.06 a month to $0.18 per month, even at a paltry $0.10/kwh cost for power, for appliances that run only a comparatively few hours per month, as the right hand column of this table demonstrates.
But for fans, which might run many hours per month, at worse power factors, there is a real, calculable cost for poor power factor, which most assuredly, a residential user will pay, even if it is just pennies per day, per motor. And that is just a delta cost, over the larger cost for the real power consumed by those fans, in pushing air around, and wasting up to 1/3 of the real power they do draw as resistive heat in their windings, if their motors are as inefficient in operation as are many older squirrel cage designs.
But things are slowly changing on the design front, for consumer electronics and appliances, and that is one reason that organizations like 80 Plus have developed specifications and designs for high power factor power supplies in consumer devices like computers, TVs and entertainment electronics, which now provide power factor correction internally through improved electronics, getting to power factors of .9, when a few years ago, such devices often ran at .6 power factor. And in the long run, more efficient choices designs in all appliances, with due regard for construction costs, keeps down utility rates, by helping utilities avoid new plant construction, and expensive peak hour generation.
But, as I said orginally, there is little that makes economic sense to do for the OP, other than to be aware of the potential costs some ceiling fans can create on the user's hydro bill, and to use them judiciously.
posted by paulsc at 2:38 AM on July 29, 2009
Calculator to figure out how much power your current refrigerator uses.
posted by smackfu at 6:33 AM on July 29, 2009
posted by smackfu at 6:33 AM on July 29, 2009
This idea for a fridge curtain makes sense.
Not to derail the fascinating power factor discussion, but can anyone confirm or debunk the idea listed above of keeping the fridge full, or filling it up with bottles of water? It does not make intuitive sense to me, except that clearly, if you filled your entire fridge with one big block of, say, cheese, it would gain no warm air upon opening and the cheese would gain little heat relative to an air exchange, so very little "cold" would be lost compared with opening the door of an empty fridge. So I'm assuming the idea is that filling up the space with stuff (bricks, whatever) minimizes the air exchange — not that the cold stuff helps re-cool the air. If that's the basic idea, then I'd submit that putting up a fridge curtain (segmented by shelf, assuming the shelves are solid) makes more sense.
posted by beagle at 7:59 AM on July 29, 2009
Not to derail the fascinating power factor discussion, but can anyone confirm or debunk the idea listed above of keeping the fridge full, or filling it up with bottles of water? It does not make intuitive sense to me, except that clearly, if you filled your entire fridge with one big block of, say, cheese, it would gain no warm air upon opening and the cheese would gain little heat relative to an air exchange, so very little "cold" would be lost compared with opening the door of an empty fridge. So I'm assuming the idea is that filling up the space with stuff (bricks, whatever) minimizes the air exchange — not that the cold stuff helps re-cool the air. If that's the basic idea, then I'd submit that putting up a fridge curtain (segmented by shelf, assuming the shelves are solid) makes more sense.
posted by beagle at 7:59 AM on July 29, 2009
Paul, now you are just being silly. You are reluctant to admit your basic misunderstanding about a power meter measuring real power, not apparent power. A user only pays for real power so to a first order approximation, power factor does not affect the user's power bill.
So you retreat to second order effects. Now it is true that there is a small increase in resistive losses in the home due to power factor, but it is only a tiny amount, a fraction of 1%. As your own table shows, a 1 hp motor only costs 6 cents a month due to power factor, not pennies a day. A fan motor is only a fraction of a horsepower, so the power factor costs the OP less than a penny a month, maybe 10 cents a year, not pennies a day.
A penny a month is not even worth talking about and there was no reason to have even brought it up except that you mistakenly thought reactive power was measured at the meter. You are just confusing the OP with a bunch of irrelevant power factor stuff.
Power factor is of great importance to the power company because it necessitates larger generators, larger transformers and hundreds of miles of transmission lines. For the user in the home it's only 50 feet of Romex. Power factor really doesn't affect their power bill to any significant amount -- it represents a fraction of 1%.
posted by JackFlash at 10:00 AM on July 29, 2009
So you retreat to second order effects. Now it is true that there is a small increase in resistive losses in the home due to power factor, but it is only a tiny amount, a fraction of 1%. As your own table shows, a 1 hp motor only costs 6 cents a month due to power factor, not pennies a day. A fan motor is only a fraction of a horsepower, so the power factor costs the OP less than a penny a month, maybe 10 cents a year, not pennies a day.
A penny a month is not even worth talking about and there was no reason to have even brought it up except that you mistakenly thought reactive power was measured at the meter. You are just confusing the OP with a bunch of irrelevant power factor stuff.
Power factor is of great importance to the power company because it necessitates larger generators, larger transformers and hundreds of miles of transmission lines. For the user in the home it's only 50 feet of Romex. Power factor really doesn't affect their power bill to any significant amount -- it represents a fraction of 1%.
posted by JackFlash at 10:00 AM on July 29, 2009
Beagle, you are correct. The theory is that filling up the refrigerator reduces the exchange of warm and cold air when you open the refrigerator. But the effect is pretty small because the specific heat capacity of dry air is small, about 1/3000 that of water. In other words, you could cool 3000 gallons of air for about the same effort as 1 gallon of water. It probably isn't worth cluttering up your refrigerator for such a small effect. If you have kids who tend to leave the refrigerator open, your mileage may vary.
posted by JackFlash at 10:25 AM on July 29, 2009
posted by JackFlash at 10:25 AM on July 29, 2009
"Paul, now you are just being silly. ..."
Not at all, JackFlash. You posted:
"... But it is the power company that takes a loss on the resistive losses due to unmetered reactive power, not the user." You are flat wrong about this, for resistive losses behind the power meter (i.e. in the user's premises wiring), as my subsequent post shows.
And:
"... Power factor correction does not benefit the user because a poor power factor doesn't cost them anything, (unless they are an industrial user subject to tariff)."
Clearly, JackFlash, "imaginary" power, costs "something," even if just in wire losses, which is all the article I posted suggested. Actually, in cheap motors, it costs more. Few high efficiency motors have terrible power factors. Most motors that are inefficient for other reasons, also have bad power factors, as a result of compromised designs. Which was, however badly my power factor example illustrated it, my main point, in my first post to this thread. And you've made no objection, whatsoever, to my thesis in the first paragraph of that post, choosing to pick apart, badly, my second.
And:
"The power factor is completely irrelevant. ..."
Power factor losses may be small, but they are obviously not "completely irrelevent" to a person who would like to keep their hydro bill "more on the $20 side, obviously." Cents count, to a person pinching pennies, JackFlash, although such small monetary amounts mean little to the large industrial site straw men you introduced to this thread. Residential tenants are not large industrial users, and their concerns are not those of industry.
How about you stick to trying to answer the OP's concerns, and take whatever electrical dick measuring contest you are interested in running with me to MeMail?
posted by paulsc at 4:19 PM on July 29, 2009
Not at all, JackFlash. You posted:
"... But it is the power company that takes a loss on the resistive losses due to unmetered reactive power, not the user." You are flat wrong about this, for resistive losses behind the power meter (i.e. in the user's premises wiring), as my subsequent post shows.
And:
"... Power factor correction does not benefit the user because a poor power factor doesn't cost them anything, (unless they are an industrial user subject to tariff)."
Clearly, JackFlash, "imaginary" power, costs "something," even if just in wire losses, which is all the article I posted suggested. Actually, in cheap motors, it costs more. Few high efficiency motors have terrible power factors. Most motors that are inefficient for other reasons, also have bad power factors, as a result of compromised designs. Which was, however badly my power factor example illustrated it, my main point, in my first post to this thread. And you've made no objection, whatsoever, to my thesis in the first paragraph of that post, choosing to pick apart, badly, my second.
And:
"The power factor is completely irrelevant. ..."
Power factor losses may be small, but they are obviously not "completely irrelevent" to a person who would like to keep their hydro bill "more on the $20 side, obviously." Cents count, to a person pinching pennies, JackFlash, although such small monetary amounts mean little to the large industrial site straw men you introduced to this thread. Residential tenants are not large industrial users, and their concerns are not those of industry.
How about you stick to trying to answer the OP's concerns, and take whatever electrical dick measuring contest you are interested in running with me to MeMail?
posted by paulsc at 4:19 PM on July 29, 2009
Look, Paul, you were the one who brought in a bunch of power factor gobbledygook that you don't really understand to the discussion and that had nothing relevant to do with the OP's question. You are talking about very small effects. A penny a month simply isn't pertinent to the discussion of a $20 bill so I tried to clear the air by pointing out it's irrelevance. It's like insisting that your speedometer must take into account the effects of Einstein's theory of special relativity, which is rather silly.
Your original reason for introducing the power factor was predicated on your fundamental misunderstanding of power metering. Rather than admitting that you made a mistake (or even better, just leaving things alone) you insisted on forging ahead on your power factor tangent making a simple OP question complicated. It isn't helpful.
posted by JackFlash at 5:23 PM on July 29, 2009
Your original reason for introducing the power factor was predicated on your fundamental misunderstanding of power metering. Rather than admitting that you made a mistake (or even better, just leaving things alone) you insisted on forging ahead on your power factor tangent making a simple OP question complicated. It isn't helpful.
posted by JackFlash at 5:23 PM on July 29, 2009
"... A penny a month simply isn't pertinent to the discussion of a $20 bill so I tried to clear the air by pointing out it's irrelevance. ..."
Ah, but JackFlash, I've already demonstrated, that power factor losses aren't, as you put it, "a penny a month." Again, you are factually wrong. And you don't want to admit it. You'd like to be right, but, factually, you aren't.
And, for a person trying to keep her hydro bill to $20 a month, rather than $40, you've yet to suggest a single cost reducing measure.
If you'd like to continue to rant about your conceptions of electrical engineering theory, why not take it to MeMail, as I've suggested? I was wiring 300 hp 3 phase motors, and ignitron welders in a sheet metal fabrication facility, in the mid 1970's, probably before you were born. I think I know a thing or two about power factor correction in industrial facilities, that might surprise you...
posted by paulsc at 5:54 PM on July 29, 2009
Ah, but JackFlash, I've already demonstrated, that power factor losses aren't, as you put it, "a penny a month." Again, you are factually wrong. And you don't want to admit it. You'd like to be right, but, factually, you aren't.
And, for a person trying to keep her hydro bill to $20 a month, rather than $40, you've yet to suggest a single cost reducing measure.
If you'd like to continue to rant about your conceptions of electrical engineering theory, why not take it to MeMail, as I've suggested? I was wiring 300 hp 3 phase motors, and ignitron welders in a sheet metal fabrication facility, in the mid 1970's, probably before you were born. I think I know a thing or two about power factor correction in industrial facilities, that might surprise you...
posted by paulsc at 5:54 PM on July 29, 2009
Response by poster: Clarification: by 'part of the bill I pay' I mean the electrical part, because the water and heat are included.
I am curious about things such as whether it uses appreciably less power to play a movie on the laptop versos on the TV. Or basically what might account for the large gap between a $20 bill and a $40 one, which was the 'range' he told me I might expect.
posted by JoannaC at 5:56 PM on July 29, 2009
I am curious about things such as whether it uses appreciably less power to play a movie on the laptop versos on the TV. Or basically what might account for the large gap between a $20 bill and a $40 one, which was the 'range' he told me I might expect.
posted by JoannaC at 5:56 PM on July 29, 2009
Best answer: Joanna, the range that your super gave you would vary depending on how much electrical stuff former tenants had and also vary with the season of the year.
For example someone with a desktop computer and CRT monitor who left it running 24 hours a day would use a lot more energy than someone with a laptop used only a few hours a day. The difference might be around 3 cents difference for each hour of running.
The refrigerator will use more energy in the heat of the summer than in winter. People tend to leave the lights on for more hours in the winter than in the summer.
One important factor is whether you are paying for heating your hot water (aside from the water bill). If so, then someone who takes baths will use more hot water than someone who takes showers. You need to find out if you pay for your water heater because that and your refrigerator may be your biggest power hogs.
All of these factors combined could easily explain a range of $20 to $40 depending on the tenant behavior and the season of the year.
Regarding using your laptop for movies vs a TV consider the following rough estimate. Let's say your laptop consumes 50 watts while watching a movie and your TV plus CD player uses 350 watts. Then the savings is 300 watts using your laptop. If your electricity costs about 10 cents a kilowatt-hour you save about 3 cents an hour while using your laptop instead of your TV. You can add up the number of hours a month you watch movies and multiply it by 3 cents to get your monthly savings.
Just running your laptop would use about half a penny an hour. Four hours a day and 30 days a month would run you about 60 cents. You could save a little by charging your laptop at work, but the savings is probably trivial.
Running a ceiling fan might cost roughly a penny an hour.
Using a CFL "smart bulb" instead of a standard incandescent bulb might save you a half penny or so for each hour the light is on.
I'm guessing that hot water and the refrigerator are the two biggest power users if your bill runs only $20 per month. Not much you can do about the refrigerator. You don't want to adjust the temperature so much that your food spoils. Most refrigerators today are self-defrosting, but if not, you want to defrost the refrigerator regularly if too much ice builds up. You should also use a vacuum cleaner to clean off the dust bunnies from the radiator coils that are on the back and/or bottom of the refrigerator.
You can save on the hot water by only taking showers.
posted by JackFlash at 6:48 PM on July 29, 2009
For example someone with a desktop computer and CRT monitor who left it running 24 hours a day would use a lot more energy than someone with a laptop used only a few hours a day. The difference might be around 3 cents difference for each hour of running.
The refrigerator will use more energy in the heat of the summer than in winter. People tend to leave the lights on for more hours in the winter than in the summer.
One important factor is whether you are paying for heating your hot water (aside from the water bill). If so, then someone who takes baths will use more hot water than someone who takes showers. You need to find out if you pay for your water heater because that and your refrigerator may be your biggest power hogs.
All of these factors combined could easily explain a range of $20 to $40 depending on the tenant behavior and the season of the year.
Regarding using your laptop for movies vs a TV consider the following rough estimate. Let's say your laptop consumes 50 watts while watching a movie and your TV plus CD player uses 350 watts. Then the savings is 300 watts using your laptop. If your electricity costs about 10 cents a kilowatt-hour you save about 3 cents an hour while using your laptop instead of your TV. You can add up the number of hours a month you watch movies and multiply it by 3 cents to get your monthly savings.
Just running your laptop would use about half a penny an hour. Four hours a day and 30 days a month would run you about 60 cents. You could save a little by charging your laptop at work, but the savings is probably trivial.
Running a ceiling fan might cost roughly a penny an hour.
Using a CFL "smart bulb" instead of a standard incandescent bulb might save you a half penny or so for each hour the light is on.
I'm guessing that hot water and the refrigerator are the two biggest power users if your bill runs only $20 per month. Not much you can do about the refrigerator. You don't want to adjust the temperature so much that your food spoils. Most refrigerators today are self-defrosting, but if not, you want to defrost the refrigerator regularly if too much ice builds up. You should also use a vacuum cleaner to clean off the dust bunnies from the radiator coils that are on the back and/or bottom of the refrigerator.
You can save on the hot water by only taking showers.
posted by JackFlash at 6:48 PM on July 29, 2009
JoannaC, I don't mean to confuse you. And, I suppose, I'm glad JackFlash has at least tried to address your concerns. But, his comments, as we''ve seen throughout this thread, can be, to be charitable, "overly broad." As follows:
"... For example someone with a desktop computer and CRT monitor who left it running 24 hours a day would use a lot more energy than someone with a laptop used only a few hours a day. The difference might be around 3 cents difference for each hour of running. ..."
As he has throughout this thread, JackFlash hasn't shown his homework. He hasn't shown his assumptions for power cost (until, perhaps, much later in his comment), power usage for a desktop computer and CRT monitor, and for a laptop. If he assumes that your power cost is a low $0.10/kwh, and that a desktop computer + 21" CRT monitor pull, together, .6 kw/hour, and that a laptop might pull, say, .3 kw/hour, then his 3 cents an hour estimate is great. However, few laptops pull as much as .3kw/hour, and most fully configured desktops + monitors + 5 channel audio rigs + Wacom tablets + scanners + laser printers, these days, pull, easily, a lot more than .6kw. So the difference between some hypothetical previous tenant with a desktop rig, and you, with a laptop, might be 3 cents an hour, plus/minus 200%+. (I suppose, in fairness, when later in his comment, he comes to an estimate of "... Just running your laptop would use about half a penny an hour." we should toss aside our notepads, and give him the benefit of the doubt, for his closer estimate, there).
Of course, none of that is really important to you, unless you happen to know what kind of computer the previous tenant was using, if any, and what his/her power bills were. It's just another meaningless "straw man" comparison JackFlash has tossed into this thread, to suggest something he believes might be true. What is important to you, is that you say you are using a Macbook. This thread indicates a Macbook, sleeping, pulls something like 37 watts, when it's charging, and 24 watts when the battery is full. However, another poster in that same thread, with better instrumentation, states that the most he could measure a Macbook using was 25 watts of power. If that poster is right, and your cost of power is $0.10/kwh, you could leave your MacBook running all day and night for a lot less than JackFlash thinks you can.
But let's continue quoting the amusing Mr. JackFlash:
"... One important factor is whether you are paying for heating your hot water (aside from the water bill). If so, then someone who takes baths will use more hot water than someone who takes showers. ..."
Pardon me, but I would say, that depends a lot on how much hot water a person taking a bath might draw, and how long a person taking a shower might be in the shower. A person drawing 6 " of warm water in a medium size bathtub, might very well pull less hot water, and incur a far smaller power bill, than a person taking a 15 minute steaming hot shower. Again, JackFlash can't be bothered to show his homework.
"... Running a ceiling fan might cost roughly a penny an hour. ..."
And then again, depending on the diameter of your fan's blades, the number of blades, the efficiency of the motor driving your fan, and other factors, as we've seen above, it might cost more. JackFlash, again, fails to show his homework. Since guessing appears to be JackFlash's preferred method of making recommendations, I'm guessing, on every bit as firm a ground as JackFlash, that it might cost you more like 5 to 7 cents an hour, and more if you also turn on the lights in a combination fan/light fixture.
"... You can save on the hot water by only taking showers."
posted by JackFlash at 9:48 PM on July 29 [+] [!]
Great advice, but, perhaps, not totally accurate, if you take 15 minute hot showers, in lieu of lukewarm, 1/2 tub baths.
posted by paulsc at 8:17 PM on July 29, 2009
"... For example someone with a desktop computer and CRT monitor who left it running 24 hours a day would use a lot more energy than someone with a laptop used only a few hours a day. The difference might be around 3 cents difference for each hour of running. ..."
As he has throughout this thread, JackFlash hasn't shown his homework. He hasn't shown his assumptions for power cost (until, perhaps, much later in his comment), power usage for a desktop computer and CRT monitor, and for a laptop. If he assumes that your power cost is a low $0.10/kwh, and that a desktop computer + 21" CRT monitor pull, together, .6 kw/hour, and that a laptop might pull, say, .3 kw/hour, then his 3 cents an hour estimate is great. However, few laptops pull as much as .3kw/hour, and most fully configured desktops + monitors + 5 channel audio rigs + Wacom tablets + scanners + laser printers, these days, pull, easily, a lot more than .6kw. So the difference between some hypothetical previous tenant with a desktop rig, and you, with a laptop, might be 3 cents an hour, plus/minus 200%+. (I suppose, in fairness, when later in his comment, he comes to an estimate of "... Just running your laptop would use about half a penny an hour." we should toss aside our notepads, and give him the benefit of the doubt, for his closer estimate, there).
Of course, none of that is really important to you, unless you happen to know what kind of computer the previous tenant was using, if any, and what his/her power bills were. It's just another meaningless "straw man" comparison JackFlash has tossed into this thread, to suggest something he believes might be true. What is important to you, is that you say you are using a Macbook. This thread indicates a Macbook, sleeping, pulls something like 37 watts, when it's charging, and 24 watts when the battery is full. However, another poster in that same thread, with better instrumentation, states that the most he could measure a Macbook using was 25 watts of power. If that poster is right, and your cost of power is $0.10/kwh, you could leave your MacBook running all day and night for a lot less than JackFlash thinks you can.
But let's continue quoting the amusing Mr. JackFlash:
"... One important factor is whether you are paying for heating your hot water (aside from the water bill). If so, then someone who takes baths will use more hot water than someone who takes showers. ..."
Pardon me, but I would say, that depends a lot on how much hot water a person taking a bath might draw, and how long a person taking a shower might be in the shower. A person drawing 6 " of warm water in a medium size bathtub, might very well pull less hot water, and incur a far smaller power bill, than a person taking a 15 minute steaming hot shower. Again, JackFlash can't be bothered to show his homework.
"... Running a ceiling fan might cost roughly a penny an hour. ..."
And then again, depending on the diameter of your fan's blades, the number of blades, the efficiency of the motor driving your fan, and other factors, as we've seen above, it might cost more. JackFlash, again, fails to show his homework. Since guessing appears to be JackFlash's preferred method of making recommendations, I'm guessing, on every bit as firm a ground as JackFlash, that it might cost you more like 5 to 7 cents an hour, and more if you also turn on the lights in a combination fan/light fixture.
"... You can save on the hot water by only taking showers."
posted by JackFlash at 9:48 PM on July 29 [+] [!]
Great advice, but, perhaps, not totally accurate, if you take 15 minute hot showers, in lieu of lukewarm, 1/2 tub baths.
posted by paulsc at 8:17 PM on July 29, 2009
Best answer: JoannaC:
Much depends, as previous posters have described, on whether you have independent metering of power to your unit, or if you share common metering, and just pay a "fair share" of a single concatenated bill for your address.
Unless you address this very different means of billing for utilities, it is difficult to correctly advise you; nevertheless, here I am, trying to "guesstimate" your power usage, from your initial post, and followups, and calculate what your financial exposure might be, if you are being separately billed for power:
"... No air conditioner or dishwasher, but I'll have two combination ceiling fan/light fixtures. I have already put in the smart bulbs. ..." If you've read this far, you've at least a couple of disparate views concerning the effects on your hydro bill, of running your fans. The power used by the lights in these fixtures, per hour, are straightforward; for the lights, it's simply the wattage they specify on the bulbs, times the time you use them = kwh used. You can get your rate per kwh from any utility bill. If you have a single 13 watt CFL bulb in each of your 2 fixtures, and use it 4 hours a day, the cost calculation is: .13K * 4H / $0.10/Kwh = $0.052 per hour, for the lights, alone.
But the rate, and the power usage, for the ceiling fans is harder to estimate, particularly if the fans are older, and physically larger, models. Worst case I can imagine, if you run both of the fans on hot afternoons, for 4 hours, and your power base rate is something like $0.10/kwh, you could spend something like $0.40 to $0.50, per day, running your fans. If you ran those fans every day, for 4 hours, you could see, in a 30 day month, something like $12 to $15, on top of the rest of your electric bill, for operating your ceiling fans. Add the lights, from the previous calculation, at about a nickel per hour, if you also run them 4 hours a day, and your total cost of operation, for 4 hours a day of fans/lights, is something like $0.70 per day, or $21 per 30 day month, for 4 hours a day of lights and fans, in two rooms.
Your refrigerator is subject to similar calculations, but you haven't given us much information about it. If it runs the 570 hours a month the table I posted previously estimates, and your power cost is the $0.10 range that makes for easy math, and your 'fridge motor pulls 3/4 HP when it runs (high, but not impossible for older refrigerators), at a power factor of only 0.75, you will be spending something like $42.75 a month to run your refrigerator. I can only hope, for your sake, that your refrigerator is a much smaller, or much more efficient model than you have thus far posted, insofar as power consumption is concerned.
"... I have a TV but will not be getting cable. ..." A lot depends on the size of the TV, the technology (CRT vs LCD or plasma), and the number of hours a day you run it. A 35" CRT Sony might be expected to consume something like 130 watts for every hour it operates. If you ran such a beast 4 hours a day on system costing you $0.10 per KwH, you'd be eating about a nickel a day in operating costs. But if you left it on, for 8 hours a day, you'd owe the power company a bit more than a dime. Do that, for 30 days in a row, and you'd need something a bit north of $3.00 to cover your TV power, despite what the cable or satellite company would charge you for programming. A 15 inch LCD screen could make pictures on 1/10 that power consumption.
"... I have a Macbook. ..." As discussed above, the power you Macbook requires, relative to your power is negligible. Toss a dime in the household kitty each month, if you feel you are taking advantage of anyone, by charging your Macbook.
"... I have a microwave and toaster oven. ..." These appliances use a lot of power when they operate, but they only operate, typically, a few minutes a day. Unless you run these appliance a long time, on average, each day, the cost of toasting an English muffin, for most toaster ovens, is something like a nickel. So, let's say you are judicious in using your appliances, and only spend something like $2 a month, heating bagels and English muffins for breakfast. That would be great, but if you add 30 minutes a day of microwave time, at 700W, for heating frozen dinners, you add something like $10.05 for microwave power to your monthly total. You can argue with yourself as to whether any of my estimates are reasonable, compared to how you actually live.
Bottom line is: For what you've described, $40 a month in power cost is minimal. Expect more, if you are individually metered.
posted by paulsc at 2:29 AM on July 30, 2009
Much depends, as previous posters have described, on whether you have independent metering of power to your unit, or if you share common metering, and just pay a "fair share" of a single concatenated bill for your address.
Unless you address this very different means of billing for utilities, it is difficult to correctly advise you; nevertheless, here I am, trying to "guesstimate" your power usage, from your initial post, and followups, and calculate what your financial exposure might be, if you are being separately billed for power:
"... No air conditioner or dishwasher, but I'll have two combination ceiling fan/light fixtures. I have already put in the smart bulbs. ..." If you've read this far, you've at least a couple of disparate views concerning the effects on your hydro bill, of running your fans. The power used by the lights in these fixtures, per hour, are straightforward; for the lights, it's simply the wattage they specify on the bulbs, times the time you use them = kwh used. You can get your rate per kwh from any utility bill. If you have a single 13 watt CFL bulb in each of your 2 fixtures, and use it 4 hours a day, the cost calculation is: .13K * 4H / $0.10/Kwh = $0.052 per hour, for the lights, alone.
But the rate, and the power usage, for the ceiling fans is harder to estimate, particularly if the fans are older, and physically larger, models. Worst case I can imagine, if you run both of the fans on hot afternoons, for 4 hours, and your power base rate is something like $0.10/kwh, you could spend something like $0.40 to $0.50, per day, running your fans. If you ran those fans every day, for 4 hours, you could see, in a 30 day month, something like $12 to $15, on top of the rest of your electric bill, for operating your ceiling fans. Add the lights, from the previous calculation, at about a nickel per hour, if you also run them 4 hours a day, and your total cost of operation, for 4 hours a day of fans/lights, is something like $0.70 per day, or $21 per 30 day month, for 4 hours a day of lights and fans, in two rooms.
Your refrigerator is subject to similar calculations, but you haven't given us much information about it. If it runs the 570 hours a month the table I posted previously estimates, and your power cost is the $0.10 range that makes for easy math, and your 'fridge motor pulls 3/4 HP when it runs (high, but not impossible for older refrigerators), at a power factor of only 0.75, you will be spending something like $42.75 a month to run your refrigerator. I can only hope, for your sake, that your refrigerator is a much smaller, or much more efficient model than you have thus far posted, insofar as power consumption is concerned.
"... I have a TV but will not be getting cable. ..." A lot depends on the size of the TV, the technology (CRT vs LCD or plasma), and the number of hours a day you run it. A 35" CRT Sony might be expected to consume something like 130 watts for every hour it operates. If you ran such a beast 4 hours a day on system costing you $0.10 per KwH, you'd be eating about a nickel a day in operating costs. But if you left it on, for 8 hours a day, you'd owe the power company a bit more than a dime. Do that, for 30 days in a row, and you'd need something a bit north of $3.00 to cover your TV power, despite what the cable or satellite company would charge you for programming. A 15 inch LCD screen could make pictures on 1/10 that power consumption.
"... I have a Macbook. ..." As discussed above, the power you Macbook requires, relative to your power is negligible. Toss a dime in the household kitty each month, if you feel you are taking advantage of anyone, by charging your Macbook.
"... I have a microwave and toaster oven. ..." These appliances use a lot of power when they operate, but they only operate, typically, a few minutes a day. Unless you run these appliance a long time, on average, each day, the cost of toasting an English muffin, for most toaster ovens, is something like a nickel. So, let's say you are judicious in using your appliances, and only spend something like $2 a month, heating bagels and English muffins for breakfast. That would be great, but if you add 30 minutes a day of microwave time, at 700W, for heating frozen dinners, you add something like $10.05 for microwave power to your monthly total. You can argue with yourself as to whether any of my estimates are reasonable, compared to how you actually live.
Bottom line is: For what you've described, $40 a month in power cost is minimal. Expect more, if you are individually metered.
posted by paulsc at 2:29 AM on July 30, 2009
If [your refrigerator] runs the 570 hours a month the table I posted previously estimates...you will be spending something like $42.75 a month to run your refrigerator. (paulsc)
paulsc might want to consult his chart again, as it suggests that a fridge runs 180 hours/month. The 570 hours cited by paulsc would suggest that the fridge compressor is running nearly 80% of the time (assuming a 30 day month), which is clearly incorrect to anyone who has ever had a fridge unless (a) the door is open most of the time, (b) you're trying to cool things down to cryogenic temperatures, or (c) the fridge is very severely broken. Using paulsc's math, which provides a reasonable rough estimate, the power consumed by your fridge is:
(180 hrs/month)*(559W [=3/4HP in Watts]) * (1/0.75 [this represents the efficiency of the fridge. and is probably a low estimate; paulsc's article suggests that 0.85 is a more reasonable efficiency]) * $0.10/kWhr = $13/month. Again, this is a large fraction of your bill, but if you're not paying for hot water, keeping it close to $20 doesn't seem unreasonable. Turn off things you don't need, and follow the advice here that isn't overly burdensome.
As an aside to those who care about paulsc and jackflash's little kerfufffle regarding power factor- let's put this to rest once and for all.
Let's say joanna's bill is $40/month [note to Joanna: I think it might be possible to keep it closer to the $20; this is just for the sake of the argument.] That corresponds to 400 kWhr at the rate we've been assuming. Let's also make the assumption (which is a worst-case scenario from a power factor point-of-view) that ALL of those 400 kWhr are from motors with power factor of 0.75. The losses in the home from reduced power factor are the result of increased power dissipation in the electrical wiring.
Using the assumptions from paulsc's article, we can say the resulting cost is is (power used / power used in the fridge in the article) * (cost of power loss for the fridge), or (400/157.9)*$0.06, or 15 cents. This is, again, the TOTAL for fans, fridge, etc.
Simply put, paulsc's argument about power factor being a major contributor does not hold water. I doubt JoannaC is worried about less than 15cents on her $20-40 hydro bill.
Now, paulsc perhaps meant to argue that inexpensive motors with poor power factors also tend to be inefficient. That argument would be perfectly valid and reasonable. Her fan might be sucking a lot of power. Or, perhaps paulsc might argue that power factor is a legitimate concern for industrial sites that are charged extra for their reduced power factor (such as his sheet metal fabrication facility). That's also a fair point. None of this, however, applies to JoannaC's situation, and is therefore not a helpful answer. Perhaps now might be a good time to just call it done?
posted by JMOZ at 6:39 AM on July 30, 2009
paulsc might want to consult his chart again, as it suggests that a fridge runs 180 hours/month. The 570 hours cited by paulsc would suggest that the fridge compressor is running nearly 80% of the time (assuming a 30 day month), which is clearly incorrect to anyone who has ever had a fridge unless (a) the door is open most of the time, (b) you're trying to cool things down to cryogenic temperatures, or (c) the fridge is very severely broken. Using paulsc's math, which provides a reasonable rough estimate, the power consumed by your fridge is:
(180 hrs/month)*(559W [=3/4HP in Watts]) * (1/0.75 [this represents the efficiency of the fridge. and is probably a low estimate; paulsc's article suggests that 0.85 is a more reasonable efficiency]) * $0.10/kWhr = $13/month. Again, this is a large fraction of your bill, but if you're not paying for hot water, keeping it close to $20 doesn't seem unreasonable. Turn off things you don't need, and follow the advice here that isn't overly burdensome.
As an aside to those who care about paulsc and jackflash's little kerfufffle regarding power factor- let's put this to rest once and for all.
Let's say joanna's bill is $40/month [note to Joanna: I think it might be possible to keep it closer to the $20; this is just for the sake of the argument.] That corresponds to 400 kWhr at the rate we've been assuming. Let's also make the assumption (which is a worst-case scenario from a power factor point-of-view) that ALL of those 400 kWhr are from motors with power factor of 0.75. The losses in the home from reduced power factor are the result of increased power dissipation in the electrical wiring.
Using the assumptions from paulsc's article, we can say the resulting cost is is (power used / power used in the fridge in the article) * (cost of power loss for the fridge), or (400/157.9)*$0.06, or 15 cents. This is, again, the TOTAL for fans, fridge, etc.
Simply put, paulsc's argument about power factor being a major contributor does not hold water. I doubt JoannaC is worried about less than 15cents on her $20-40 hydro bill.
Now, paulsc perhaps meant to argue that inexpensive motors with poor power factors also tend to be inefficient. That argument would be perfectly valid and reasonable. Her fan might be sucking a lot of power. Or, perhaps paulsc might argue that power factor is a legitimate concern for industrial sites that are charged extra for their reduced power factor (such as his sheet metal fabrication facility). That's also a fair point. None of this, however, applies to JoannaC's situation, and is therefore not a helpful answer. Perhaps now might be a good time to just call it done?
posted by JMOZ at 6:39 AM on July 30, 2009
Response by poster: Thank you for the replies, everyone! Much appreciated.
posted by JoannaC at 5:28 PM on July 31, 2009
posted by JoannaC at 5:28 PM on July 31, 2009
This thread is closed to new comments.
posted by jschu at 6:17 PM on July 28, 2009 [1 favorite]