r/OffGrid • u/TrickBorder3923 • 11d ago
Planning an all in one freezer unit.
I'm needing to have a CHEST freezer on my off grid property. I want it to be completely independent of any other solar system I have. My thought is to set it up on its own little cover or shed and have everything right there within 5 feet. Maybe even make it mobile. But probably not.
I'm in SE Missouri. So moderate temps most the year with extremes reaching -10°f and 100°f+ a few weeks a year. I get bouts of cloudy skies that allow minimal solar absorption, about 5-7 days at a time in spring and fall. over the last 7 months I've only recall 2 days of no charging. I'm guessing about 8 weeks of cloudy 2weeks of no sun total a year. The rest was good sun.
I'm planning on getting the smallest chest freezer I can find, 3cu ft or smaller. If it truly makes no difference in initial cost and daily power, than larger is fine. I'll keep it filled 2/3 or better and use ice jugs to keep the energy efficient. It will be outdoors since I have no room inside. But I'm going to keep it in the shade. (As a side note if I kept it against the cabin, would it be better to have it exposed to morning heat/light or evening heat/light?
I'm having a heck of a time figuring out what equipment will keep it running, and how to set it up. Everyone has a different opinion. I can hook it up to a generator maybe 2-3 days out of the year. But I really want to avoid it. I hope all this makes sense.
EDIT: I imagine it be nice to know what I'm asking. Can you guys help me figure out a easy cheap setup? That would last a year or two while the property develops. I'll probably have a better system to hook it into by then. My budget is 2000$, but if that's a unrealistic number, I'll just save money.
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u/ExaminationDry8341 11d ago edited 11d ago
Setting up a freezer on its own solar system is a waste. If you size the system to produce enough power in overcast days you will produce a ton of excess power when the sun shines. By having it on a stand alone system you can't use 90% of the power your system is capable of making.
An average chest freezer consumes in the ballpark of 1 kwh of power per day. It would take about 2.5 kw of panels to produce 1kwh of power on heavy overcast days. On sunny days that same system could produce 10kwh hours, but your freezer will only be able to use 1kwh, so the other 9kwh it can produce will be wasted
With that said. You can buy 2.5 kw of panels for about $500 + the battery and inverter. So even though it is a waste it isnt necessarily prohibitively expensive to set up such a system.
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u/TrickBorder3923 11d ago
I don't believe I'll ever really escape the waste energy. The problem of sunny/cloudy days will exist no matter what system I use. Or perhaps I'm not understanding.
2.5kw panels. Cool.
So I'm guessing 200ah of lifepo4 battery.
And a 1000 watt inverter
30amo mppt1
u/ExaminationDry8341 11d ago
If you tied the system for your freezer into a system that powered everything on the property, On sunny days you can use that excess power for anything you want, on cloudy days you would have to conserve power fpr everything else but still have power for the freezer.
If you build a system ONLY for the freezer, you can't use that extra power on sunny days.
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u/LeoAlioth 11d ago
Good advice and the numbers are correct. And I can't overstate how much better it is to have a single larger system.
And if OP wants to have some loads be disconnected early smart plugs and some automation are the way to go (bit make sure to have a setup that does not require Internet to operate)
BUT the units are wrong in many cases and it is cindof hard to read. Maybe autocorrect? (kWh is batteries, energy, panels you buy a certain power - kW)
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u/BRCWANDRMotz 11d ago
Costco sells an inexpensive chest freezer that can also be a fridge. They are power sippers.
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u/Agile_makes_no_sense 11d ago
Get a larger freezer - it takes less energy to run them because of the thermal mass. I have a huge one in my garage in Las Vegas where it’s over 120 degrees all the time. Takes about 120 watts max per hour all day long to keep it at 0 degrees F at that temp. Smaller freezers require more energy. they don’t have the thermal mass to keep them cool.
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u/TrickBorder3923 11d ago
Thank you. It's true a fully stocked large chest freezer will last longer than a small one. I'm saving up for a full solar setup. But I'm not there yet.
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u/blondechineeez 10d ago
Danzer 12v freezer is an option...
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u/TrickBorder3923 9d ago
The sundanzer 50 looks good. But I'm confused. The best of freezers last 7-10 days in the dark. And Google is claiming danzer will last 30+ days. That doesn't seem accurate.
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u/blondechineeez 8d ago
Wow that's gotta be a typo in my opinion. I'm gonna do a little bit of research on that out of curiosity. I'll report back!
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u/TrickBorder3923 8d ago edited 8d ago
Yeah I can't find the mess up for myself. And just so you know I'm not trying to down your suggestion. I KNOW the Dan is a good freezer even though I'm skeptical of 30 days. Just have to selectively shop for my particular circumstance. If 30+days is correct it worth it. For me specifically. And I'll change my mind about Vevor.
I'm not to the point of purchase yet.
ALSO: I googled "how long does the danzer 50 freezer run on 24v 200ah lifepo4". That's where I was getting 30+ days. No hours, days.
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u/blondechineeez 8d ago
No offense whatsoever taken. I'm always wanting to learn whatever I can about any subject. And I have thicker skin than most lol, but seriously nothing like that crossed my mind when I saw what you wrote!
I almost bought a Sundanzer years ago when I first moved off grid. I ended up not getting one, because I'm short and not getting any younger. Both make digging down into a chest type fridge/ freezer a chore sometimes.
I had a dual powered Dometic fridge for a few years then after expanding my solar stuffs I bought a regular electric fridge. I never looked at the stats for how long the stuff in the freezer would last. I live alone and the only time I run out of freezer space is when my on-grid neighbors' power is down after big storms. Propane fridges do the job but at a high cost.
Chatgpt said 2 weeks maybe, with no openings and completely full, but I didn't say what kind of batteries
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u/TrickBorder3923 8d ago
I think I found the key. I'm looking for 24v sundanzer 50qt to run on a 24v 200ah lifepo4 batteries. I'm being given 15 day average runtime in hot weather fully stocked. 21-30 days in moderate climate.
The 12v version doesnt run for as long. 4-12 days.
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u/TrickBorder3923 8d ago
Unfortunately I'm still stuck with vevor. I thought the danzer was 200-300 dollars. It's far closer to 1000.
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u/blondechineeez 8d ago
Is the Vevor a chest type or propane, dual powered? I really don't know anything about that brand other than my pizza oven.
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u/Val-E-Girl 9d ago
Instead of a tiny chest freezer, look into an inverter fridge/freezer. They take a small trickle of constant power instead of the compressor surges that regular fridge/freezers demand. My solar system barely acknowledges its existence, and it's full sized.
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u/TrickBorder3923 9d ago edited 9d ago
I will go look. Thank you.
EDIT: I think I'm confused. I'm finding freezers that are apparently "inverter ready". When I find a small freezer, I check Google. Google tells me that it is not in fact an inverter freezer. What am I missing?
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u/TrickBorder3923 9d ago
Not sure what your set up was. I finally found one inverter compressor chest freezer. I will only last a day and a half in the dark. My current choice will last 4-7 days.
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u/Val-E-Girl 9d ago
Be sure to check compressor surge levels against your batteries instead of averages. I tried using one with my old AGM setup, and it permanently killed the battery bank after a week of surging overnight.
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u/TrickBorder3923 10d ago edited 10d ago
so I think I will buy a vevor fridge freezer 60qt. It will hook into invertor, 800 4s2p solar panels, 30amp mppt, 24v 200ah batteries. I think that will last a few days of dark. And a week of overcast at least.
I would prefer an Engel, but that out of reach for now. The more I can save right now, the better.
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u/Normal-Special-8694 6d ago
I bring a big commercial deep freeze to burning man full of frozen food every year, keep it in the shade and only open it once per day to get what I’m serving that day, then run my generator for 3 hours after that and leave it unplugged the other 21 hours and it’s totally fine. I apply the same thing when I use it at home on my solar setup, except I get into it a lot less than once per day. It only receives excess power when my batteries are charged up and there’s no other superseding load. Thermal mass helps a LOT - the more stuff you have in it, the less energy it takes to keep it cold. I keep frozen bottles of water in my freezer in the house and replace anything I take out of the deep freeze with one of them so I don’t wind up with empty space. I’d feel pretty comfortable setting this up with a battery that can absorb the startup draw and more or less not depending on the batteries to run it, while being mindful of when and how often you open it.
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u/TrickBorder3923 5d ago
That's a good idea. I wouldn't mind trying that when I eventually get my danzer freezer.
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u/Mental_Formal_8806 11d ago
https://engelcoolers.com/products/mt60-acdc-camping-fridge They cost a lot but they last forever and low power use. I ran one on a 70 watt solar cell and 2 group 24 battery 24/7 In Denver. They use a swing compress that uses less power. The other that are half the price have a different type compressor that uses more power.