Dedicated System For Fridge

monoloco
monoloco Solar Expert Posts: 103 ✭✭
in Off Grid Solar & Battery Systems #1
Looking for opinions on what would be the optimum array size, inverter, and battery bank to run 1 modern 18 cu. ft. standard household refrigerator. I am looking at a replacement system for my small gas fridge and don't want to tax my current battery bank. I live in an area with over 300 days of sunshine a year. I currently have 2) 140w and 1) 75w Evergreen panels that I am not using for anything that I could dedicate to refrigeration.
· Share on Twitter

Comments

  • unicornio
    unicornio Solar Expert Posts: 217 ✭✭
    #2
    Re: Dedicated System For Fridge
    monoloco wrote: »
    Looking for opinions on what would be the optimum array size, inverter, and battery bank to run 1 modern 18 cu. ft. standard household refrigerator. I am looking at a replacement system for my small gas fridge and don't want to tax my current battery bank. I live in an area with over 300 days of sunshine a year. I currently have 2) 140w and 1) 75w Evergreen panels that I am not using for anything that I could dedicate to refrigeration.

    you can buy a true solar frigde. they are so good, but so expensive...in some case you need to buy a fridge and freezer apart, both can work like fridge or freezer....they normally are a chest style...

    http://sundanzer.com/solar-power-refrigerators/chest-style/

    this one is only fridge, but only need a 400w solar array, and not need battery nor charge controller!...
    http://sundanzer.com/wp-content/uploads/BFRV55-Brochure.pdf
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #3
    Re: Dedicated System For Fridge

    The question would be how much power that 'frige actually uses.

    My 16 cu.ft. not-so-new draws approximately 1.2 kW hours per day. On the 24 Volt system that's about 50 Amp hours just for the 'frige. Since some of the running is during daylight hours that eases things a bit. I have a 232 Amp hour battery bank, so the total is around 25% DOD during non-sun hours for everything.

    I also have generators in case the sun doesn't shine.

    Absolute minimal 'frige system in my opinion would two GC2's for 220 Amp hours @ 12 Volts, a good sine wave inverter of 1kW+ (to handle the start surge), and about 400 Watts of panel on a 30 Amp PWM controller or 350 Watts on an MPPT controller to recharge. Plus something to power it if the sun doesn't shine.

    If your 'frige uses less, you can get away with less. But frankly it's not easy to down-size from there; a smaller system could actually cost more. You could really couldn't reduce the inverter size without losing the ability to start the 'frige.

    Just my POV, feel free to disagree.
    · Share on Twitter
  • monoloco
    monoloco Solar Expert Posts: 103 ✭✭
    #4
    Re: Dedicated System For Fridge
    unicornio wrote: »
    you can buy a true solar frigde. they are so good, but so expensive...in some case you need to buy a fridge and freezer apart, both can work like fridge or freezer....they normally are a chest style...

    http://sundanzer.com/solar-power-refrigerators/chest-style/

    this one is only fridge, but only need a 400w solar array, and not need battery nor charge controller!...
    http://sundanzer.com/wp-content/uploads/BFRV55-Brochure.pdf
    My wife would never be happy with a chest refrigerator.
    · Share on Twitter
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #5
    Re: Dedicated System For Fridge

    I have a Meanwell TN-1500-124F (24V ) inverter that has a built in charge controller that I use for my dedicated Refrigerator 25 cf power source. I am on the second year and no issues yet.

    There are all kinds of versions. The (F) is a GFI plug in, (G) is hardwire.

    http://www.powergatellc.com/dc-ac-inverters.html

    http://www.powergatellc.com/mean-well-tn-1500-124f-dc-ac-inverter.html

    http://www.powergatellc.com/mean-well-tn-1500-dc-ac-inverter.html
    · Share on Twitter
  • Desert Rat
    Desert Rat Solar Expert Posts: 147 ✭✭✭
    #6
    Re: Dedicated System For Fridge

    There are several 18 cu. ft. refrigerator/freezers that are rated at 383 kWh/year. My girlfriend has such a fridge, and I have measured daily use at 1500 watt-hours with an ambient temp of 105°F. With one of those, I believe you would be fine with Cariboocoot's suggested system size, given your sunny location in BCS. That size system is just barely enough, so bigger would be better, or at least a generator for cloudy days. I'm not a fan of the Sundanzer units--your money is better spent on solar panels to run a conventional AC refrigerator.
    · Share on Twitter
  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    #7
    Re: Dedicated System For Fridge

    Mono
    My fridge is a sears 18cf. rated at 392 kw a year, so a little more than 1kw a day. I checked it with a killawatt and was amazed at its power consumption. During the cooler months it averaged 900 to 1000 watts a day but in the summer when it was hot in the house the consumption jumped to 3kw a day. I have no idea what yours might draw but that is something to consider when sizing your system.
    HTH
    Larry
    · Share on Twitter
  • unicornio
    unicornio Solar Expert Posts: 217 ✭✭
    #8
    Re: Dedicated System For Fridge
    monoloco wrote: »
    My wife would never be happy with a chest refrigerator.

    we are all affected by a vertical design that is not rational, our wives and ourselves. the kitchens are established for upright fridge design.

    however it is nothing ingenuous to make a refrigerator with vertical doors, and if you look, you see that is rarely that the industrial fridges and freezers are vertical, except when occupying a entire room or building ...

    after being using a refrigerator horizontally for more than a year, I can assure you it is much more comfortable, has more capacity and consumes less than a quarter, much better keeping the freshness of food (which has a minimal loss of cold when used and that means less temperature variation on them), and having an ability to cool food in less time when we introduce them in the fridge. it even do not need a light inside, because the normal light enters perfectly from above...;-)

    vertical fridge/freezer is only one more of our bad vices, that shows an erroneous way of life. however the refrigerator vice is more evident since it operates 24 hours a day... and keeps inside our food (and our beer!).
    · Share on Twitter
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #9
    Re: Dedicated System For Fridge

    LG now advertises a 2 door, inner and outer doors, to keep the inner portion colder by limiting the 'escape' of all the cold air when you open the door, as on a standard fridge.

    Not sure how efficient that improvement works. NO consumption ratings listed http://www.lg.com/ca_en/refrigerators/lg-LFX31945ST-french-3-door-refrigerator

    30.5 Cu ft 20.5 fridge 10 freezer C$4300 MSRP 350 lbs
     
    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
    West Chilcotin, BC, Canada
    · Share on Twitter
  • monoloco
    monoloco Solar Expert Posts: 103 ✭✭
    #10
    Re: Dedicated System For Fridge
    westbranch wrote: »
    LG now advertises a 2 door, inner and outer doors, to keep the inner portion colder by limiting the 'escape' of all the cold air when you open the door, as on a standard fridge.

    Not sure how efficient that improvement works. NO consumption ratings listed http://www.lg.com/ca_en/refrigerators/lg-LFX31945ST-french-3-door-refrigerator

    30.5 Cu ft 20.5 fridge 10 freezer C$4300 MSRP 350 lbs
    Holy mackerel, that thing is a beast, appliance porn, I'm not even going to show that to my wife.
    · Share on Twitter
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #11
    Re: Dedicated System For Fridge
    monoloco wrote: »
    Holy mackerel, that thing is a beast, appliance porn, I'm not even going to show that to my wife.

    wow, i don't blame you for not showing it to her. price is criminal imho. lucky for me i can't fit a refrig that big here, but if you need much more than that amount of cuft you might consider a walk-in.:-)
    · Share on Twitter
  • bmet
    bmet Solar Expert Posts: 630 ✭✭
    #12
    Re: Dedicated System For Fridge

    I wonder if there are any inverters out there, specifically designed for running a refrigerator? there could be a substantial market for such a product.
    · Share on Twitter
  • unicornio
    unicornio Solar Expert Posts: 217 ✭✭
    #13
    Re: Dedicated System For Fridge
    bmet wrote: »
    I wonder if there are any inverters out there, specifically designed for running a refrigerator? there could be a substantial market for such a product.

    there is not is necessary to make an inverter for each thing. the important, to keep in mind, is that for an electric motor can works (refrigerator, pump, compressor ... etc) need to have a pure sine wave inverter, and to able to hold a peak at the start, about three times more power that are consuming by the electric motor in question.
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #14
    Re: Dedicated System For Fridge
    bmet wrote: »
    I wonder if there are any inverters out there, specifically designed for running a refrigerator? there could be a substantial market for such a product.

    How about a refrigerator designed to run off an inverter instead?

    That's where the real problem is: because utility power is "limitless" there has been little need for companies to invest in soft-start or even low power usage.

    Now if they'd incorporate the same technology as used in the mini-split A/C units they'd have something. :D
    · Share on Twitter
  • unicornio
    unicornio Solar Expert Posts: 217 ✭✭
    #15
    Re: Dedicated System For Fridge
    Cariboocoot wrote: »
    How about a refrigerator designed to run off an inverter instead?

    That's where the real problem is: because utility power is "limitless" there has been little need for companies to invest in soft-start or even low power usage.

    Now if they'd incorporate the same technology as used in the mini-split A/C units they'd have something. :D

    hi, Coot, i agree with this...
    some sundanzers are CC and the AC units have soft start...
    · Share on Twitter
  • monoloco
    monoloco Solar Expert Posts: 103 ✭✭
    #16
    Re: Dedicated System For Fridge
    Cariboocoot wrote: »
    How about a refrigerator designed to run off an inverter instead?

    That's where the real problem is: because utility power is "limitless" there has been little need for companies to invest in soft-start or even low power usage.

    Now if they'd incorporate the same technology as used in the mini-split A/C units they'd have something. :D
    It would also be nice if they would design them so the defrost cycle could be programed for times when your batteries are charged up.
    · Share on Twitter
  • monoloco
    monoloco Solar Expert Posts: 103 ✭✭
    #17
    Re: Dedicated System For Fridge
    bmet wrote: »
    I wonder if there are any inverters out there, specifically designed for running a refrigerator? there could be a substantial market for such a product.
    What is the most reliable small inverter big enough to run a fridge? Is their anything like the 300w Morningstar only a bit bigger?
    · Share on Twitter
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #18
    Re: Dedicated System For Fridge
    monoloco wrote: »
    What is the most reliable small inverter big enough to run a fridge? Is their anything like the 300w Morningstar only a bit bigger?

    The problem is the 1kW+ start-up demand as most 'friges will draw <200 Watts running. Wayne has some running off MS 300, but not without a lot of effort.

    A good 1kW sine wave inverter will start and run most refrigerators.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #19
    Re: Dedicated System For Fridge

    One person here has successfully converted a chest type freezer or three (as I recall) to run on a single 300 watt MorningStar TSW inverter (rated for 600 watts for 10 minutes at I recall).

    Wayne from NS Canada did a lot of work to find the optimum capacitor for the freezer starting circuit. Set up a buck transformer to drop the starting voltage and increase the starting current (a bit). And sequencing relays so that only one fridge/freezer would receive AC power at a time (and when one shut off, the next compressor would get power, etc.).

    It was a lot of work. And has worked well for many years (as I understand). But, probably not frost free units and "simple" chest units (maybe a non-frost free standup fridge too).

    Easier to get a ~1,200-1,500 watt minimum AC inverter (TSW preferred) and you can run a typical energy star rated frost free fridge/freezer and some other loads at the same time too.

    Even then, not all 1,200-1,500+ watt AC inverters are created equal (and not all loads are equal too). Modern Frost Free fridges/freezers typically have electronic timers that reset to zero if AC power is removed (i.e., inverter "sleeps" and "sweeps" to save idle power). So, when power is "restored", they usually immediately start a defrost cycle (~500-600 watts of heater+circulating fans).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #20
    Re: Dedicated System For Fridge
    monoloco wrote: »
    It would also be nice if they would design them so the defrost cycle could be programed for times when your batteries are charged up.

    Or
    1) only when needed - maybe a photo cell to measure real frost buildup, instead of a timer to clear Florida humidity.
    2) not start a defrost cycle at power up. Heck, if the power was off, it likely does not need to defrost anyway.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

    · Share on Twitter
  • H2SO4_guy
    H2SO4_guy Solar Expert Posts: 213 ✭✭✭
    #21
    Re: Dedicated System For Fridge

    I run refrigeration off of Exeltech XP-1100's. Any of them will work just fine and are a true sine wave. 1100 watts and 2200 surge for a few minutes. They can be had for about $600 from NAWS, but I bought most of mine for $300 or less used. Other than having an old Trace C-40 charge controller fail and kill one, I have had great service from them. I have heard (but not confirmed) that Exeltech (Made in U.S.A. BTW) will repair most for $100 exchange plus shipping, so it keeps them running for not too much money. Sometimes they can be had pretty reasonably. I paid $35 each for 3 of the pure sine wave Exeltech XP-125's in 24 volt. I think I may need a support group to attend or something, don't even have a 24 volt setup (Yet!!!!)

    Good luck and let us know how it goes.
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
    · Share on Twitter
  • CDN_VT
    CDN_VT Solar Expert Posts: 492 ✭✭✭
    #22
    Re: Dedicated System For Fridge
    monoloco wrote: »
    It would also be nice if they would design them so the defrost cycle could be programmed for times when your batteries are charged up.

    There is a mechanical or electronic timer , electronic is unplug at just before peak ,it will start with defrost ,, mechanical is turn the timer till click & watch the kill-a-watt heater come on at peak .. then every 24 , it should be in line Sir.

    VT
    · Share on Twitter

Categories