# Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Posts: 163Solar Expert ✭✭✭✭✭
I have a Frigidaire 26cf Side by Side. Manufactured 07/2004

I just finished running my Kill-A-Watt meter on it for EXACTLY 24 hours. Surprising (to me) results.

With the compressor running and the freezer fan blowing.....1.3A and 158 watts.

In 24 hours, it used 2.91Kwh

Dividing 2,910 Watt hours / 24 hours = 121 watts per hour average.

At idle (compressor off, freezer fan ON)....30 watts

But the label inside says...115V / 8.5A. So I previously was calculating 115v x 8.5A = 977.5 Watts
Obviously, I was mistaken. Big time.

The fridge Energy Star rating for this refrigerator was VERY good....actually among the best for all side by side 26cu ft fridges in 2004

Right now, I have two, 125Ah batteries. 125Ah x 2 x .85(inverter eff) x .5 (Batt discharge depth) / load (121watts avg)

So instead of my fridge running 1 hour (at 977watts, it should run more like 10 hours on the two batteries)
HUGE and very encouraging difference. Kill-A-Watt meters are your friend.

Am I missing something here? Should the defrost cycle have run at least once during that 24 hour period?

After calculating a 1 hour run time on two batteries, even 4 hours is fantastic.
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• Posts: 17,615Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Your batteries will supply at most 1500 Watt hours. Actually it will be less because you have to power the inverter and also lose some in the conversion to AC. If you convert to AC you get about 1275 Watt hours.

Your refrigerator by your own measurement uses 2910 Watts hours per day, or an average 121 Watts per hour.

1275 Watt hours / 121 Watts = 10 hours run time at best. At that point the batteries will be at 50% SOC and in danger of not recovering. It is much better than 1 hour.

Yes, the defrost cycle will probably run at least once per day. There are a number of factors that affect this and the refrigerator's draw in general. Including ambient temperature and humidity and how often you open the door.
• Posts: 5,087Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Most fridges have a ~ 10 hour timer on the defrost... Why 10? don't know, and the defrost cycle is about 1/2 hour... so 2 per 23 hr day

KID #51B  4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
• Posts: 163Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
Your batteries will supply at most 1500 Watt hours. Actually it will be less because you have to power the inverter and also lose some in the conversion to AC. If you convert to AC you get about 1275 Watt hours.

Your refrigerator by your own measurement uses 2910 Watts hours per day, or an average 121 Watts per hour.

2910 Watt hours / 121 Watts = 10 hours run time at best. At that point the batteries will be at 50% SOC and in danger of not recovering. It is much better than 1 hour.

Yes, the defrost cycle will probably run at least once per day. There are a number of factors that affect this and the refrigerator's draw in general. Including ambient temperature and humidity and how often you open the door.

I know right?

I'm really glad to learn that my current system can power my full size fridge overnight...maybe even a little more.
My number one priority for emergency power is keeping the fridge running and it appears with the investment I've already made
I have achieved that goal. It is no problem to add 2 more batteries and enjoy even longer run times or raise the discharge point.
I'll just need to add Solar panels until I have a system capable of re-charging all my batteries quickly enough once the sun rises the next day.

I see nothing wrong with a happy ending:cool:

(Although, this simply opens the door for more possibilities and further investment)
• Posts: 17,615Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Yes, that's the problem with solar; once you get a taste of it you want more!
• Posts: 209Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

I would leave that meter on there for a week or so to get a more accurate measurement. Most energy star 25 CF refrigerators today are coming in somewhere around 500 KWhr/year. Your refrigerator is using twice that, according to your measurements. I bet ice production has a lot to do with daily energy used. Maybe try manually turning the icemaker off for a day or two and see if your numbers improve.
• Posts: 163Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
I would leave that meter on there for a week or so to get a more accurate measurement. Most energy star 25 CF refrigerators today are coming in somewhere around 500 KWhr/year. Your refrigerator is using twice that, according to your measurements. I bet ice production has a lot to do with daily energy used. Maybe try manually turning the icemaker off for a day or two and see if your numbers improve.

Thanks VF.
Ours is 26 Cu Ft. It's a 2004 model.
I do know that the newest 26 Cu Ft refrigerators use even less energy, even though mine is not bad.
We do in fact use the icemaker. You make a good point.
Next time I test it I'll try turning the icemaker off for that 24 hrs.
I'll have to determine if making ice during an extended power outage is a priority or should be turned off.
• Posts: 867Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
I'll have to determine if making ice during an extended power outage is a priority or should be turned off.

Depends on how the neighbours feel about watching you enjoying an ice filled beverage while they are all sweltering with no A/C.

You could always keep a bag of ice cubes in the freezer, rotate it through stock...like Bill (BB) does with his generator gas supply. Power goes out you kill the ice making feature because you already have some on hand. My fridge is all fridge, I've forgotten what ice in a drink is like.

\ralph
• Posts: 3,009Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
I'll have to determine if making ice during an extended power outage is a priority or should be turned off.

It could also be a tradeoff between having the unneeded luxury of having ice for a few hours, or being able to continue running your fridge during an extended outage which would give great joy to any jealous neighbors you may have.
Seriously, the folks "in the know" on here who abide waste are extremely few and far between. I'm sure by now you must have seen their motto: Conserve, conserve, Conserve.
My fridge? A converted freezer. It's average consumption per 24 hours? 200 watt hours / 0.2 Kwh. Granted it doesn't have an icemaker, and is half the size of yours, but yours still consumes roughly 7 times more electricity per CuFt than mine does. But hey, to each his own. Oh, and I run it very close to the freezing point, I like ice water and that's exactly what I get
• Posts: 163Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
It could also be a tradeoff between having the unneeded luxury of having ice for a few hours, or being able to continue running your fridge during an extended outage which would give great joy to any jealous neighbors you may have.
Seriously, the folks "in the know" on here who abide waste are extremely few and far between. I'm sure by now you must have seen their motto: Conserve, conserve, Conserve.
My fridge? A converted freezer. It's average consumption per 24 hours? 200 watt hours / 0.2 Kwh. Granted it doesn't have an icemaker, and is half the size of yours, but yours still consumes roughly 7 times more electricity per CuFt than mine does. But hey, to each his own.

Well,
My better half "OWNS" the kitchen. She does all the cooking and loves to cook. And is good at it so I can't complain.
But, she picks out the kitchen appliances.

I want to run the Kill-A-Watt again on the kitchen refrigerator WITHOUT the Icemaker turnd on and see what diff it makes.

I do have two refrigerators in the Garage. But I haven't checked their usage yet.
One is a small college dorm type 2.0 cu ft unit (which I hear will use as much energy as the big ones.)
And the other is a backup side by side which more than likely uses MORE energy than the one in the kitchen.

Now the Garage....THAT's ALL MINE. She has no say about the garage.
• Posts: 5,087Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

I think I hear "we'll see about that " coming from the kitchen.

KID #51B  4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
• Posts: 1,925Solar Expert
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
I'm sure by now you must have seen their motto: Conserve, conserve, Conserve.

In my mind conserving doesn't mean getting by without things that you want to have. Conserving is not austerity. Conserving is using means and devices that use less energy and at the same time provide the same (or better) level of service.

I've never had a fridge with ice-maker before. Now I have big fridge with ice-maker. And I like the ice-maker. I use it even in winter. The fridge does consume ~2kWh/day, but that's not bad. It's much better than my old smaller fridge without ice-maker, which used to consume 4kWh/day. That is conservation - I use less electricity and at the same time have better life.

Could I conserve more? Sure. I could switch the fridge off for the winter and store food in a box outside - it's freezing out there. I would save some electricity, but my life would get worse. That doesn't look like conservation to me. That's austerity. In the end, 200 years ago people used to live without electricity. Can I do that now? Absolutely! But I see absolutely no reason to do that.
• Posts: 1,807Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

I pretty much agree with NorthGuy. We have bought some energy efficient appliances and have improved energy efficiency of our home over time in other areas. But we like conveniences too. So my motto for a long time has been "I don't believe in conserving renewable energy - I believe in making more of it".
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Chris
• Posts: 2,334Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
ChrisOlson wrote: »
I pretty much agree with NorthGuy. We have bought some energy efficient appliances and have improved energy efficiency of our home over time in other areas. But we like conveniences too. So my motto for a long time has been "I don't believe in conserving renewable energy - I believe in making more of it".
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Chris

We do too Chris ... but! As we look at our current RE systems we are always looking for ways to make life better. When our AC units needed replacing we improved our AC efficiency allowing us to have 2 Plug-in cars. We add insulation to the house allowing us to add the workshop/office building loads. In that workshop/office we used mini-splits to cool as needed with the triple zone they offered. We load shift to buy cheap off peak to save money for other things like a kitchen remodel or new hardwood flooring. Sometimes conserving is the better part of valor and is much cheaper than adding more RE, all with the idea of making life better.

I think managing RE is just as important as adding more. Jeez now I sound like the Coot! LOL 8)
• Posts: 867Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

We might have figured that out about you Chris, if we read between the lines. Lots of solar, lots of wind (production), lots of battery, lots of toys in general. Lots of solitude to play with the toys.

I've thought about generating more, but it would only be beneficial from Nov through Jan. \the rest of the year we have sufficient for needs, or almost. April's utility consumption was 42kwhrs. Solar 180kwhrs, wind 96kwhrs. Those utility hours might cost \$5.00 (plus \$45 line fees). I don't hate the utility company as much as some here might. The load sservice was re-installed when the feed in tarrif system went on line. Transformer was there so why not? It's nice to have the shop fully functional again.

Ral;ph
• Posts: 1,807Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
Ralph Day wrote: »
We might have figured that out about you Chris, if we read between the lines. Lots of solar, lots of wind (production), lots of battery, lots of toys in general. Lots of solitude to play with the toys.

I've thought about generating more, but it would only be beneficial from Nov through Jan.

We've done without a lot of things for a long time. We put our youngest daughter thru medical school, which was a 10 year adventure (for both her and us). After that was accomplished we decided to spend some money on ourselves for a change. We have never had AC in the house but that is the latest thing we have now.

We want to have a decent quality of life with the normal conveniences that other folks have. And I do not mind running the generator at bad parts of the year to support that lifestyle. The generator, to us, is the "grid". It's our power source that works when everything else fails. When we get up in the morning in the dead of winter when it's -30 outside and no incoming power - we still want our morning coffee make in our electric coffee maker, and to make ham and eggs on the electric range. It's what my wife and I like. And we are not going to make compromises. We'll run the generator to enjoy what we like before we'll go without. A lot of off-grid folks don't look at it that way.
--
Chris
• Posts: 17,615Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

A lot of off-grid folks are not, to put it in perspective, rich.
All that energy production comes with a cost, and that cost is always higher than not needing it in the first place. It's amazing what you can do without when you've never had it to begin with.
• Posts: 1,807Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
All that energy production comes with a cost, and that cost is always higher than not needing it in the first place

Anybody who lives off-grid realizes that it's more expensive that living with utilities. It's not a thing that's cheap in the first place.

Everybody who lives off-grid has their reason why. Some enjoy a more conservative lifestyle of independence, some enjoy the location and grid isn't available, some think society is going to collapse so they want a "prepper" lifestyle, and the reasons go on. For the seasonal off-grid home, you do without a lot of things and it's fine. When you live there everyday, especially thru the dead of winter when things get really tough, there comes a point where you're either going to go the distance or give up on it because you get tired of it and simply can't do it anymore.

There seems to be a sort of "romance" with off-grid living. It's not romantic. It's a lot of work, takes a lot of ingenuity, and costs money. How comfortable you want to make it depends on how much money you want to spend on it, and how much work you want to put into it.

I have lost track of the number of people that know us that think we "got it made". I tell them, "oh yeah? Go to your utility panel and turn off the Main and break off the handle so you can't turn it back on, and imagine the utility company is going to charge you \$168,000 to put a new handle back on the breaker. You are now off-grid. No power. No water. No heat in the house. No AC. Figure it out. Your problems have only just begun. You'll find out just how much we 'got it made'."
--
Chris
• Posts: 17,615Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Having both an off-grid place and an on-grid place (with really cheap electric) I fully understand the difference.

One of the repeated themes on the forum is people wanting to reduce their electric bill by going off-grid, followed by a dozen or so forum members explaining how that doesn't happen.

I have become hyper-sensitive to these issues in the past year. The last big project that was supposed to fund retirement did not turn the profit that it should have (none, in fact) leaving the finances way short of what they need to be. Worse, my health took a drastic turn for the worse making all the effort necessary to maintaining the off-grid place extremely difficult for me.

The price of off-grid power comes in three parts: money, effort, and inconvenience. To some extent they are coefficient and can be balanced one against the others.
• Posts: 1,807Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
I have become hyper-sensitive to these issues in the past year. The last big project that was supposed to fund retirement did not turn the profit that it should have (none, in fact) leaving the finances way short of what they need to be. Worse, my health took a drastic turn for the worse making all the effort necessary to maintaining the off-grid place extremely difficult for me.
.

'coot - EXACTLY. That's what we're looking at. When we get to be 65-70 we're going, "are we going to want to continue doing this, or even CAN we continue doing it?" We have had a long winter this year and just about ran out of wood. Without the wood our house goes cold - we have no backup. In March when it became evident we had better start conserving a bit by turning down the thermostat and cutting back on wood consumption, I could not get in the woods to get more wood out. The snow was up to my neck and the skidder simply wouldn't go in it. I looked at the situation - sun was shining beautifully in our March days and I wished I had some backup solar heating. Guess what my newest project is going to be this summer?

We decided we're not going anywhere. This is our home. And we have to do now what it's going to take in 10 years to still be here. And if we don't we're going to have to give up on it because it's simply too much work once we reach the point where we can't we can't do it anymore. And if and when that point comes, it would kill us to have to leave our home that we've worked so hard to build.

It's not easy, man. You have to make decisions and choices. I could say, well I can fix this by just putting up more wood. Problem solved. For now. Or I can spend some money now on putting in some solar heating that takes less labor so that when I'm 65 I can keep up with the amount of wood I have to put up for the winter. My theory is that I can reduce some of the inconvenience part of your three part off-grid requirements by putting in the money and effort now while I can do it, to reduce the inconvenience later.
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Chris
• Posts: 17,615Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Well I'm out of money and can't manage the effort so all I've got left is the inconvenience.
• Posts: 1,807Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
Well I'm out of money and can't manage the effort so all I've got left is the inconvenience.

That's not good, but I still like your equation:
Money + Effort + Inconvenience = Off-Grid

The equation has to balance no matter what. Reduce any one of the things on the left side and you have to increase another one to keep it balanced.

You should write a book, "Off-Grid Living Guidelines", based on that equation, and sell it. The effort would go into the book, it would probably sell like hotcakes and maybe you could increase your money - and reduce some of that inconvenience 8)
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Chis
• Posts: 1,807Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

I got one of those kill-a-watt meters and I plugged it into the wall for our 'fridge yesterday after reading this thread. I was curious, as I have never checked the thing. Our 'fridge is a top and bottom one with the freezer in the top. It is a Frigidaire from 1994. I think it defrosts maybe twice a day, but not sure on that as I don't pay a lot of attention to it.

But anyway, it used 1.8 kWh from yesterday noon when I plugged it in until just now. I know it uses more in the summer. And I think it uses more than that normally. We have not had a fire in the furnace for two days and it's down to 65 degrees in the house so the 'fridge has not run much. Plus with only my wife and I here, we don't open it very often, which lets warm air in (or does the cold leak out??).

But I still think it's pretty good for 1994 'fridge.

It's running watts is 133.
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Chris
• Posts: 1,925Solar Expert
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
ChrisOlson wrote: »
Money + Effort + Inconvenience = Off-Grid

I definitely balance this with effort.
ChrisOlson wrote: »
You should write a book, "Off-Grid Living Guidelines", based on that equation, and sell it. The effort would go into the book, it would probably sell like hotcakes and maybe you could increase your money - and reduce some of that inconvenience 8)

Or you can go to solar consulting business, and you will definitely be better at this than 99% of existing solar consultants.
• Posts: 125Solar Expert ✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

For those who want to conserve energy but still run a 110v fridge, we turn off our Magnum inverter when we go to bed, turn it back on in the morning. We have done this for several years WITH a 110 fridge/top freezer and a chest freezer. The food says cold (butter still hard in the am, ice cream in the top freezer hard but not "rock hard", this saves quite a bit of energy use while not hurting anything so far.

So the refrigerator and freezer are running all day and well into the night, but there are 8 hours or so when they are off, without consequences. you could also put them on a timer for the same result if you wanted the inverter on all night...
Magnum4024PAE, 2 Midnite Classic 150s, 3100watts solar, 432ah lifepo4 battery.  Off grid since 2004.
• Posts: 163Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

Whew !!

Back on track! Hoo-Rah!

For a few posts there I thought my poor little Kill-A-Watt Refrigerator thread had been HI-JACKED.....nooooooooooooooo
• Posts: 1,925Solar Expert
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
For a few posts there I thought my poor little Kill-A-Watt Refrigerator thread had been HI-JACKED.....nooooooooooooooo

One man's "hijacking" is other man's "thinking outside the box"
• Posts: 163Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
bbbuddy wrote: »
For those who want to conserve energy but still run a 110v fridge, we turn off our Magnum inverter when we go to bed, turn it back on in the morning. We have done this for several years WITH a 110 fridge/top freezer and a chest freezer. The food says cold (butter still hard in the am, ice cream in the top freezer hard but not "rock hard", this saves quite a bit of energy use while not hurting anything so far.

So the refrigerator and freezer are running all day and well into the night, but there are 8 hours or so when they are off, without consequences. you could also put them on a timer for the same result if you wanted the inverter on all night...

I'm no thermodynamics engineer but.......

Won't the fridge STILL gain "some" heat energy overnight (lose some of the cold due to transference)
So now, in the morning when it comes back on, you need more energy to drive that heat energy back out
and get everything back down to the daytime, normal cold level?

I do not think it's thermodynamically possible for the fridge to maintain the "exact" state over 8 hours with no external input.
But, I've been wrong before......once. (lol)
• Posts: 2,334Solar Expert ✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
I'm no thermodynamics engineer but.......

Won't the fridge STILL gain "some" heat energy overnight (lose some of the cold due to transference)
So now, in the morning when it comes back on, you need more energy to drive that heat energy back out
and get everything back down to the daytime, normal cold level?

I do not think it's thermodynamically possible for the fridge to maintain the "exact" state over 8 hours with no external input.
But, I've been wrong before......once. (lol)

True but if the sun is up it can come off the panels instead of drawing off battery all night long.
• Posts: 17,615Banned ✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours

A certain amount of lateral thinking is inevitable in these threads.
If it strays too far we do try to redirect or start new threads on the subject.
But sometimes it's hard to tell just when 'the line' has been crossed.

Basically we're still talking about refrigerator power use and how to reduce it.
• Posts: 163Solar Expert ✭✭✭✭✭
Re: Full Size Refrigerator - I ran the Kill-A-Watt on it for 24 hours
solar_dave wrote: »
True but if the sun is up it can come off the panels instead of drawing off battery all night long.

Ahhhhhh....good point.

Grasshopper is learning.
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