Energy efficient refrigerators on solar power?

softdown

Finally got my 48 volt system operational. Seems to be an abundance of power for one person. When I found an unused energy efficient refrigerator for $400, I couldn't resist. It is a Samsung RB1855SW that was made in July, 2003 yet never used. For sale at a Habitat Restore. Plugged it in and found that it is quiet and cools at a good rate.

This model costs $44/year to operate according to ratings. Employs separate compressors for the fridge and freezer and offers about 19 cubic feet of storage. I had been looking at a vert small fridge at Costco then noticed that it cost $37/year to operate according to ratings.

Now I am thinking that energy costs a lot less in 2003 than now. So perhaps my fridge isn't quite the energy miser that I had hoped. It uses max power of 3.2 amps. Samsung rated it an A for energy efficiency when it was offered for sale. Parts are still easily available.

Have read about highly efficient fridges but wasn't looking forward to buying a new one. It has been impossible to buy a used energy efficient fridge in the past. I think many people were donating their old fridge and buying newer, more energy efficient refrigerator. Budget is tight and expenses for being off grid never seem to end.

Have two weeks to return it. Though it is a project to bring it 220 miles to my mountain shop.

H2SO4_guy

Plug your Kill-A-Watt (Order one now if you don’t have one, I think Home Depot carries them sometimes for around $30) and see how much energy your unit really uses in your situation. I got a 1997 used medical refrigerator for $80 and while it does keep veggies longer by about a week and keeps the temp within 1 degree Celsius, it uses about 4.5 kwh per day for about 14 cu. Ft. refrigerator only! That’s a lot. I want the Danby refrigerator only 17 cu ft unit, but funds are going elsewhere for awhile.

I was also looking for a ‘Slightly Used’ forklift battery and checked several out. Some of the shops order used cells to get the ones working that they can, so there is that option. Most fail because one or more cells fail and then you are left with mismatched cells if you go the used cell replacement route.

Took cookies for 12 weeks to a battery place where it is the last stop before the smelter. I started going with used 8D flooded. Mine are mismatched and don’t have full capacity, but way cheaper. They let me look through there various batteries and gave me a really good deal on whatever I wanted. After all, anything over scrap was more profit for them.

They would get used L-16’s, but not enough matched, as they usually came out of lifts or floor scrubbers. They also wanted way too much for those. Their least desirable ones to them were stationary batteries. I got 56 Panasonic 2 volt cells @ 1040 AH. That works out to 2 strings of cells with 6 spares. I run 2 parallel strings for 2080 AH @ 48 volts and have 6 spares charged every month @ 12 volts. That gives me all matched cells with quite a few spares.

Not counting lead trade-in, I have $2,000.00 in batteries. I am at the 22 month mark, so spending less than $100.00 per month on batteries. Gives me about $6.50 worth of usable electricity.

Good luck and let us know how it works out.

softdown

Their theory was smaller compressors use less energy in the long term. The downside (isn't there always a downside?) is that the compressors will be on more. One of my ramps slid over the lug holding it in place and the fridge was on its side for a minute. Wondering if I should let it sit for awhile after all the jostling of moving and setting on its side for a minute. I know nothing about refrigeration.

Your equation of spending less than $100/mt on batteries for $6.50 worth of electricity somehow has failed to impress me yet.

Mountain Don

softdown wrote: »

This model costs $44/year to operate according to ratings.

Go by the KwH rating, not the $$g by the $$ on the label our 1999 storage tank style water heater is cheaper to run than a present day on-demand water heater.

H2SO4_guy

I seem to recall that a compressor should be upright for several hours if it has been on it’s side to let the oil get back to where it’s supposed to be. Wouldn’t hurt anything to not plug it in for awhile.

Wasn’t trying to impress anyone, just sharing my experience about going on the road less traveled with batteries. Most of the used fork truck batteries are bringing around $2,000.00 and how long they last is a crap-shoot. While cells can be swapped out, then it is a mismatched pack and there are issues with that. I used to have a GNB 500 AH @ 48 volt fork truck battery. It stored about $1.50 worth of usable electricity and it was a challenge to move around. Weighed 2035 pounds including the steel case. I have an engine hoist on steel wheels to move it around.

I do several things outside the norm for off-grid power. It isn’t about the money, I could have had power poles set and had way cheaper grid power, but wanted autonomy. Almost bought a home in Weston Colorado, but couldn’t get the water issue worked out. Hauling water in the mountains would be a killer. That is such a beautiful area. Fantastic views.

waynefromnscanada

H2SO4_guy wrote: »

I seem to recall that a compressor should be upright for several hours if it has been on it’s side to let the oil get back to where it’s supposed to be. Wouldn’t hurt anything to not plug it in for awhile.

I once worked with a retail outlet that handled fridges. Some, but not all of them had marked on the outside of the carton which SIDE should be UP, if it were to be laid down, thus preventing compressor oil getting up in the refrigerant lines. Others, we had factory info that they should be standing upright for 2 hours before connecting power and starting it - - IF it had been on it's side during transportation, thus permitting any oil in the lines to find it's way back tot he compressor. .

softdown

It uses 547 Kw hours/year.....that was good back then.

Used 181 watts for about five minutes upon plugging in. Then it shifted gears and went to 230 watts for a bit. Currently sitting at 190 watts. Seems to be a "soft start" compressor.

I like the digital temperature read out displays.

Should have studied first. http://www.greenbuildingadvisor.com/...t-refrigerator

They do a lot better now. Mine wouldn't even earn an energy efficient rating these days. Oh well.

softdown

Looked around plenty. Sears offers a section with nothing but Energy Star units.

http://www.sears.com/appliances-refrigerators&Yes_Sears/b-1020022?filter=ENERGY%20STAR%20Compliant_storeOrigin&sortOption=PRICE_LOW_TO_HIGH&subCatView=true&viewItems=50

cupcake

BEST *small refrigerator for off-grid living below:

https://www.youtube.com/watch?v=YrHN6iTMtvM

30 watts. Cheap. Works

Try it!

softdown

Now I have a little Buyers Remorse. Had a 20% off coupon though. With the money I saved, I can buy two more panels to run the fridge. Always liked big fridges. Last one was a big side by side.

Ethan Brush

cupcake wrote: »

BEST *small refrigerator for off-grid living below:

https://www.youtube.com/watch?v=YrHN6iTMtvM

30 watts. Cheap. Works

Try it!

Caky do you have one and if so have you verified the watt draw? I have a real hard time believing that figure, I suspect his math or meter is wrong.

Mountain Don

This one may be it ???

FWIW, the yellow label states 270 KwH a year. For a 3.1 cu ft fridge & freezer that is actually a lot of electricity. We have an 18 cu ft top freezer whose label states 355 KwH a year.

Photowhit

Ethan Brush wrote: »

Caky do you have one and if so have you verified the watt draw? I have a real hard time believing that figure, I suspect his math or meter is wrong.

The video shows a little flakey guy, 2 harbor freight sets and 2 marine starting batteries.... NOT a sustainable system!

The 30 watts is per hour, over a 24 hour period or 720 watt hours in a 24 hour period. (I think they said 740watt hour) So the duty cycle is already taken into account. Also doesn't say anything about ambient temperature. I think my small 2 door fridge used about the same most of the year, more in the summer if I was away and cabin temps ran up to high 80's low 90's.

softdown

Batteries down to 88% SOC early this morning. Yesterday was pretty cloudy and I charged some tool batteries while putting the new fridge through the paces. Security cameras etc normally take batteries down to 95% SOC by early morning.

softdown

Concerned now....battery state shows "discharging" at 1:00 MST. It is a cloudy day here. Fridge is usually consuming 7 watts I think. Kill a Watt meter is partially clouded over so readings are a bit of a guess. Battery SOC is now 85%. Strange....why is the CC in float mode instead of bulk mode?

BB.

What is the battery bank DC voltage?

How do you know 85% SOC? What is telling you that?

-Bill

Dave Angelini

BB. wrote: »

What is the battery bank DC voltage?

How do you know 85% SOC? What is telling you that?

-Bill

Yea how about specific gravity? Most of the new 22 cubic foot refrigerators in Tier 3 energy star are around 400 KWH per year.

softdown

Both the Gel and 8D banks measure 55.6 volts using a voltmeter under float charge.
Panels are producing 78-82 volts/string.
Maybe that 85% SOC is from earlier this morning. But why does the system say that it is discharging I wonder. It isn't that cloudy today. Not using much energy either.

softdown

Batteries have slipped to 84% SOC. It really is a cloudy day most of the time. That is the culprit by my estimation.

Photowhit

How are you reading the battery state of charge? What meter or device?

softdown

Outback FlexOne Mate. Batteries now reading 83% SOC. I think this is the tell tale readout: In: 18 Ah Out: 50hA Bat: -32 Ah
Guess I better read the manuals pretty soon. Dry as dust...

Photowhit

I'm not an outback guy, but I think you can set the charge controller to replace amps lost after float. Might be a good question for the Outback forum! Though there are a lot of people around here that use them.

cupcake

Ethan Brush wrote: »

Caky do you have one and if so have you verified the watt draw? I have a real hard time believing that figure, I suspect his math or meter is wrong.

No the math on this fridge is correct, it consumes on average 30watt hours. Its the real deal, and the guy who posted the youtube review of it is not a n00b to solar...

Its a Kenmoore, sears sells it, it only uses 30watthours... our is running as I write this... and it gets ice cold as seen in the video...

-- sweet cake in a hot cup

cupcake

Photowhit wrote: »

The video shows a little flakey guy, 2 harbor freight sets and 2 marine starting batteries.... NOT a sustainable system!

The 30 watts is per hour, over a 24 hour period or 720 watt hours in a 24 hour period. (I think they said 740watt hour) So the duty cycle is already taken into account. Also doesn't say anything about ambient temperature. I think my small 2 door fridge used about the same most of the year, more in the summer if I was away and cabin temps ran up to high 80's low 90's.

I have been LIVING with this fridge running 24/7 for nearly 2 years.-- its 30 watts! The fridge is the real-deal. They guy in the video is not flakey, its how he talks. His little harbor freight set up is not his main setup, it was used to test it...

Also photowhit, for the millionth time, 2 marine batteries ARE sustainable depending on where you live, I, like the guy in the video live in the DESERT, its 100% sun here every single day, all day long. The panels and battery banks are SUBSTANTIALLY lower out here due to the wheather. I dont even have a kilowat in panels and the fridge, fan, washer are all running right now....


The fridge is 30watt hours - I saw the guys video, bought one, tried it myself, he wasnt BSing. What's more is that you can adjust the settings... he had his on full -blast, I have minez on half... the AC stuff comin out these days is super-efficent. Even the cielign fans have DC motors and use only 17 watts on 'high'.... the washer I have has a DC inverter motor, etc, etc... you just gotta search and be realistic and theres tons of stuff to be had...

but again, I and the guy in the vid live in the land of everyday sun

If you want I'll post up my own vid of this fridge running on solar...


-- cake in a cup

cupcake

Photowhit wrote: »

The video shows a little flakey guy, 2 harbor freight sets and 2 marine starting batteries.... NOT a sustainable system!

The 30 watts is per hour, over a 24 hour period or 720 watt hours in a 24 hour period. (I think they said 740watt hour) So the duty cycle is already taken into account. Also doesn't say anything about ambient temperature. I think my small 2 door fridge used about the same most of the year, more in the summer if I was away and cabin temps ran up to high 80's low 90's.

I have been LIVING with this fridge running 24/7 for nearly 2 years.-- its 30 watts! The fridge is the real-deal. They guy in the video is not flakey, its how he talks. His little harbor freight set up is not his main setup, it was used to test it...

Also photowhit, for the millionth time, 2 marine batteries ARE sustainable depending on where you live, I, like the guy in the video live in the DESERT, its 100% sun here every single day, all day long. The panels and battery banks are SUBSTANTIALLY lower out here due to the wheather. I dont even have a kilowat in panels and the fridge, fan, washer are all running right now....


The fridge is 30watt hours - I saw the guys video, bought one, tried it myself, he wasnt BSing. What's more is that you can adjust the settings... he had his on full -blast, I have minez on half... the AC stuff comin out these days is super-efficent. Even the cielign fans have DC motors and use only 17 watts on 'high'.... the washer I have has a DC inverter motor, etc, etc... you just gotta search and be realistic and theres tons of stuff to be had...

but again, I and the guy in the vid live in the land of everyday sun

If you want I'll post up my own vid of this fridge running on solar...


-- cake in a cup

Ethan Brush

Ok well if its 30 watts average, not just while running then that explains it. Plus you have inverter inefficiencies then. That is not that good compared to a "real" dc off grid fridge, but I admit it is pretty good for a ac consumer unit. For comparison , my DC novakool uses about 26 watts while running and runs at maybe a 20% duty cycle, plus no inverter losses. If I had your sun I would likely get one....

cupcake

Ethan Brush wrote: »

Ok well if its 30 watts average, not just while running then that explains it. Plus you have inverter inefficiencies then. That is not that good compared to a "real" dc off grid fridge, but I admit it is pretty good for a ac consumer unit. For comparison , my DC novakool uses about 26 watts while running and runs at maybe a 20% duty cycle, plus no inverter losses. If I had your sun I would likely get one....

"Real" DC fridge costs 5-10 times more, than this Kenmoore 30watt AC fridge available off the shelf at sears...

naw mean?

--cc

Ethan Brush

Yup......5 times as much, at least for the novakool (a little smaller that the kenmore). In my climate cheaper to pay that than the additional batts and panels to get it through the winter months.....

Photowhit

cupcake wrote: »

Also photowhit, for the millionth time, 2 marine batteries ARE sustainable depending on where you live, I, like the guy in the video live in the DESERT, its 100% sun here every single day, all day long. The panels and battery banks are SUBSTANTIALLY lower out here due to the wheather. I dont even have a kilowat in panels and the fridge, fan, washer are all running right now....

I'm sorry, I'll kindly disagree I could do the math for you, but unsustainable has to do with 2 batteries and even a 30 watt load 24 hours a day. 90 watts of harbor freight panels likely produce about 70 watts in direct 'solar noon' 4-5 hours a day and I'll even give you 5 hours! on either side at 1/2 that. So the 10 hours that it produces 35 watts, the inverter and fridge are eating every bit of that, the 1/2 of the 70 watts that is available for storage is a total of 175 watt hours... How long do you think the system will be sustained?

BTW - If you're going to bad mouth me, at least quote me correctly, I said the "system is NOT sustainable".

That is with out talking about how useless marine type batteries are....

I will not encourage the use of them unless you have an emergency situation.

If you had been on the forums since the usenet bulletin boards, as I have, you couldn't count the number of times marine batteries have disappointed people, not to mention the harbor freight solar panel kits.

If you have something personal against me, that's fine. But I'll put my solar back ground and resume' up against most people's, I'm approaching 15 years of living off grid and I can throw in another couple years of a sailboat system, a total loss bicycle system that work it's intended 9 months of cycling....

softdown

Starting to think that my Mate is simply acting up. Battery voltage is around 13 volts after disconnecting from CC. So the declining SOC (down to 73 now) and message that batteries are losing charge seems like a bug. Electronics and I just don't seem to get along.

westbranch

not sure I saw this rating table listed http://library.cee1.org/content/qualifying-product-lists-residential-refrigerators