50AMP, 240v - 12,000 Watts

Solar4All

Someon build better battery technology please.
Hello, New here. Looks like a great solar forum!

I have an off-grid project with open budget.

Looking to power 50AMP, 240v - 12,000 Watts circuit for welding unit or anything else rated for such a circuit.
No batteries. Setup will only run off solar panels during peak time.
Location San Diego
Space for panels is 960 sq. ft. prefer to stay around ~36 standard size panels.

What All-in-one off-grid solar Inverter(s) is a good choice?
What panels do you recommend? (prefer to spend more for higher watt panels unless there is a really good bang for the buck panel that would still fit the space requirements)

My initial thoughts are:

(36) ~400W panels like the LG415's

and a Growatt 12,000W 48V Inverter (120AMP / 250V)

Recommendations?
 
Last edited:

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
Sadly it isn't that simple. The gotcha is no batteries.... They are the buffer and without it you'll have varied power and a welder will strain that to the limit at best. Standard Mono-Facial Panels are less complex to install but Bi-Facial can give you great gains IF properly installed to make good use of it and yes it is a little more complicated but not by much. The surge when you hit the trigger is HUGE so without any question you are Limited to Low Frequency Pure Sine Wave with TRANSFORMER. None of the Transformerless or HF (High Frequency) Inverters will survive a MIG or other High Draw welder. I use a MIG on my solar system occasionally and it is brutal and so I use it with my genset when I have to she the job size demands it. (anything more than a quick 2" long weld = genset)

Such use cases are best served with paralleled inverters for load sharing purposes, the Growatts can do so with the proper models. A Hybrid model capable of taking AC from Grid/Genset (via AGS to autostart/stop a Generator) and handle a respectable battery bank is the better all around solution.

SantanSolar sells both New & used Panels and Bang for Buck that's the place for Panels, check it out:

Inverter spec clarifications....
Growatt 12,000W 48V Inverter (120AMP / 250V)
Means it can output 12,000W from a 48V Battery Bank. That is 48V X 250A = 12,000W AC. 12,000÷120VAC=120VAC/100A or 240VAC/50A not corrected for inverter efficiency.
120A is likely representing the Charge Capability for Battery Banks.
250V is the DC Input allowable for the MPPT Solar Controller.

A basic LFP 48V Battery Pack requires 16 LFP cells, one BMS (Battery Management System) and one Fuse per pack.
16 Matched & Batched 280AH cells with Factory Matching Report $125 USD ea, $2000 USD
-- Shipping for above by GUessTimator is $1000 +/- Accurate quote only by opening Chat/Messenger session with vendor.
1, 250A Capable Smart BMS from $200 & up, budget $300
1, 250A Fuse $30-$50 pending on type.
That would provide 48V/280AH/ 14.3kWh or 14,336Wh. for <$3500 USD.

And it is not rocket science or very hard to put together, see the 2nd link in my Signature for a Document that gives you all the pertinent information and reference links.

Note the Vendor I am quoting is one of our best Know Good vendors who has supplied a LOT of cells to members here. Luyuan Tech and Amy Wan.

Hope it helps, Good Luck
 

Solar4All

Someon build better battery technology please.
Setup needs to be done without batteries. If I have to use double, triple, etc the amount of panels then so be it. I get that source has a huge surge, but if you have enough electricity coming into the all-in-one inverter should it not be able to handle it? No one is making an all-in-one inverter to handle a 50AMP, 240V, 12,000W circuit?
 

HRTKD

Boondocker
I don't know about Growatt, but my solar charge controllers don't respond instantaneously to changes in load. The batteries pick up the slack.

What is your aversion to using batteries?
 

kromc5

Solar Addict
I'm still learning but I would have to believe that is going to be difficult. Considering a 42-amp load on the breaker side translates to 110 amps on the battery. I'm wondering if the conversion would be similar to the panels as well? I'm still rewiring the panels due to misinformation but before with 36 500w bifacial panels I was just able to stay positive with 5400watt load. It's taken 4 days to pull hundreds for feet of wire but I should be done today. Steve talked about the growatts, I have two of the 12kw growatts but they require a battery.

I remembered mpp had an inverter that ran with no batteries but they won’t let you tie 9 together without a battery.

Due to the inconsistent nature of PV power, batteryless mode can only work normally under single-unit setup.

This is a good point when the winds are up and the clouds are coming in the voltage measured at the combiners can really fluctuate.
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
I did mention Growatt - The Solar Models "Hybrids" are limited to the number of models if you do;t want a battery. There are other Inverter systems that can do this but never get mentioned here. Then of course there are those which can take Microinverter on Panel input to provide direct house power (no grid) but I don't know much about them as they are outside my interest... being a Rural & Remote off grinder.
 

NwCali

Solar Addict
Given that money is not object, why not contact the big boys direct? I'm sure a few million will get you a "space station" setup. :)
 

Solar4All

Someon build better battery technology please.
I don't know about Growatt, but my solar charge controllers don't respond instantaneously to changes in load. The batteries pick up the slack.

What is your aversion to using batteries?
No aversion to batteries. If the only workable solution requires batteries then I will use them. Trying to design the system without batteries. Batteries add cost and maintenance. They are the first part of the system to go typically and I do not need them if I can come up with a system that does not require them. I should be able to throw panels at the problem. Just need to figure out the inverter setup. Thanks.
 

Solar4All

Someon build better battery technology please.
I'm still learning but I would have to believe that is going to be difficult. Considering a 42-amp load on the breaker side translates to 110 amps on the battery. I'm wondering if the conversion would be similar to the panels as well? I'm still rewiring the panels due to misinformation but before with 36 500w bifacial panels I was just able to stay positive with 5400watt load. It's taken 4 days to pull hundreds for feet of wire but I should be done today. Steve talked about the growatts, I have two of the 12kw growatts but they require a battery.

I remembered mpp had an inverter that ran with no batteries but they won’t let you tie 9 together without a battery.

Due to the inconsistent nature of PV power, batteryless mode can only work normally under single-unit setup.

This is a good point when the winds are up and the clouds are coming in the voltage measured at the combiners can really fluctuate.
Thanks for the (36) 500W bifacial panel to 5400W load stat. I am thinking about the same panels. Also, looking at the LVX6048 and running multiple separate units. If I run the unites separate as stand alone units I should not need batteries. Need to check with MPP and get some more details.
 

Solar4All

Someon build better battery technology please.
Since the LVX6048 is good for 6kw and do not require batteries when stand alone, I assume I could setup 3 of these as separate units for 18kw total. As long as I do not allow them to talk to each other I can run them without batteries and tap into the combined power for my load. I am sure there are more then a few people out there who have done something similar.
 

Solar4All

Someon build better battery technology please.
Use a bank of ultra capacitors and slap an active balancer on it and call it a battery?
Yes, if I have to use batteries using super capacitors is a good idea. They last longer then batteries, have high cycle counts, and can handle the surge. That might be the way to go for this design.
 

Wibla

Engineer
They last longer then batteries, have high cycle counts, and can handle the surge.
You realize that there are other battery technologies out there than just lead acid, right? And that most of them require little to no maintenance when compared to lead acid?

LTO would be pretty great for a smaller high-draw pack that can sustain surges.
No aversion to batteries.
Setup needs to be done without batteries.
No batteries. Setup will only run off solar panels during peak time.
Right-o...
 

curiouscarbon

Science Penguin
+1 for LTO.

Very power dense. Very long life. Application implies little need for deep discharge, suggesting *even longer* life on top of LTO’s crazy long lifespan.

supercap or LTO are my personal favs

people making crazy high amperage bass emitting vehicles often use LTO to handle the transient draw 🙂
 

Daveyclimber

New Member
If this is a short term project why not just use a generator or rather a engine driven welder. Way cheaper in the short term for power generation. Otherwise batteries will need to be in the mix somewhere.
 
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