Paranoid prepper question….
If you had a big quality chest freezer filled with food. And the grid power went off permanently. would everything in the freezer still stay frozen and fine if you had solar on your house but not a battery? So the freezer would only kick back on in day time and then just stay frozen while off (not opening it much) during the night?
Would that work?
If Grid Power Was Cut off. Could a Freezer Run on Just Solar?
ego22 on 03/07/2022 - 17:47
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This for on-grid solar power system without a battery. The inverter is shut off without grid power. I dont remember why thats the case.
It’s because otherwise workers will get electrocuted when they try to fix the wires, if solar is feeding energy into it which can't go anywhere
Yeah i think that was it.
I was more thinking not browning out home appliance when the inverter cannot fully generate power for the instantaneous consumption
There's isolation switches to do that (plus the touchy subject of roof top isolators, introduced by the guys sitting in offices for fire fighters to disable your solar, except in reality they are the major cause of rooftop solar fires)
@bamzero: The good news is that rooftop isolators are no longer required. https://www.pv-magazine.com/2021/11/23/australia-removes-muc…
I understand this, but why not simply shut off the feed in, and let the solar owner have their power. This surely isn't rocket science.
@jrvb42: I think you need a battery for that to act as a sponge to absorb the extra power generated and release extra power when less is being generated. I don't think it is as simple as just throw away some of the power (I'm not an electrical engineer though)
Yeh, it is because solar alone isn't a stable source and you'd get brown outs from cloud cover.
Well thats. just. crap… Back to the drawing board..
Also freezer wont stay below -20C without power overnight
Sometimes it's not sunny for a few days in a row… if you want to go this path you'd need a backup generator.
Just add a battery and make sure you tell your installer you want to be able to use the solar when there is a blackout (as that's not guaranteed by just having a battery).
You can get an inverter/battery system that allows what you are proposing and stays connected to the mains, in this case the mains is your back up and if it drops the solar/battery continues to operate while posing no risk to utilities workers.
Fronius Gen24 can run your house on solar if the grid goes down.
I just looked at some data on the PV point feature. Thats what people intuitively expect solar power inverter to function
Only through one power point unless you have battery backup.
What happens if a cloud passes over, wouldn't all your stuff brown out/break?
Obviously great idea on a full sun day.
Maybe have a UPS plugged in then your item plugged into the UPS
@Xistn: If it is just operating during the day it should be OK. It's only to keep the power constant even with clouds passing over etc.
Chest freezers are pretty energy efficient!
If you are curious, get one of those power draw meters and monitor the freezer for 24 hours, it only draws power for ~ 4-6 hours a day (assuming no opening) …
A fully charged ZBM3 flow battery can power our 750L chest freezer for just over 3 months :D
The newer ones have 100w compressors. I was surprised, as normally cheap appliances use 200w compressors, but I guess it makes sense. The less on/off cycling they do, and the lower the compressor power relative to condenser size, the more efficient they run.
Ps 3 months? Thats crazy! I never even heard of zinc bromine flow batteries before but they must be strong
No wonder, it's a 10KWh battery and nearly 800mm square :D
Interesting battery though, had never heard of them before. How do they compare $/W to Lithium?
Cheaper and last longer as Lithium eventually breaks!
With flow batteries, you can just replace the liquid in 15-20years and instantly restore capacity, with Lithium you have to buy the whole thing again :/
We have three in the garage (they stack easily)
I would love to get a ZBM3. Would you mind sharing how much they cost (ball-park)?
If the grid went off permanently, you’re going to have a lot of issues that will last after the food in the freezer has run out.
If you want really low power use off grid then don't use a freezer. Get that well insulated chest freezer and run it at fridge temperature using an eBay thermostat. Get rid of the less well insulated upright fridge which uses a lot more power.
Then start storing food which doesn't need any power because it's preserved.
Then start spinning your own wool lolIf the power is off permanently, its time to get used to many fewer calories, untreated health problems, feeling cold in winter and hot in summer with few options and working bloody hard to get enough clean water and food to eat.
And that assumes security isn't a problem.Probably no annual KPI reviews though, traffic will be a lot better, and the price of GPUs won't be as big a deal.
"and the price of GPUs won't be as big a deal."………..that got me going, good one.
In Papua New Guinea we used to just plug a generator into any power point during blackouts and power the house. Can you do that? And then get a small bank of batteries attached to the inverter… why do these solar power batteries cost so much more than camping 100AHr ones? Size? Why can't we get small set ups to just let us have emergency power for judicuous use?
I would hope one day we'd get small battery/generator units for backup costing $2-3k for our solar setups. The 2?kW generator starts automatically when battery at x%….
o just plug a generator into any power point during blackouts and power the house.
Any slightly fried linesman who called in to debate the dangers of that probably wouldn't use their voice to communicate their displeasure…
Any slightly fried linesman
OP is a prepper. End of the world scenario. No linesman on call. No phones to call. No power on grid. No reflective vests. Noooothing around …
Psst: "remove main fuses before plugging"
Chest freezer is best for cold retention but as others have said, you need to sort out some batteries to have a power feed.
Would that work?
With cloudy, dark wintry weather as we had it? Nope
With cloudy, hot and humid summery weather as we had it? NopeWith shinning sunny days? How well insulated your freezer is? How well insulated the room having the freeze is? Does the freezer run during the night?
Too many variables pointing to a "probably not".
Solar inverters usually shut off completely when mains power is cut. It’s a safety thing so that they don’t feed in to a grid that is down. So no.
There are some inverters that have a special power point that can be powered from solar while mains is down. That might work - but you’d have to check that the freezer starting load wouldn’t exceed what the inverter can supply to it.