Solar panel help.

[MT59918]

I have the Growatt SPF 3000TL LVM and 2 24v 280ah lifepo batteries. This is for an off grid application in northern MT. I need to decide what panels to buy next. I have a quote for brand new panels wiring and mount for $3200 shipped for 6 Rec n peak 330w panels. The 6 panels are $1300, shipping is $1000, the rest is the mount and wiring misc. But I just found these panels for sale on FB marketplace. They are 45 mins away. Ad says they are new. Tags shows manufactured in 2018 and they are asking $1600 for 12 panels that I can use to build the system out as I expand, use 6 for now. They are REC twin peak 350w.

so if I ran 2 strings of 3 panels of the 330w I’m at 1980 total watts and 123 Voc. If I did the same thing with the 350w panels it would be 2100w and 140.1 voc. Max is 145 voc and 2000w for the Growatt.

would I be pushing to much with the 350 panels? They are much cheaper than the 330. This is why I’m asking the question

This is the first time building something like this.

 

[OnTheRoadAgain]

At 24v, 2000Watts is the maximum rated PV array power for that unit.

There are ways to bleed off that extra 100Watts, however, before the controller

It "probably" would handle the extra 100watts.....but.......

 

[MichaelK]

For a COLD environment like northern Montana, you really need to focus attention on what your solar voltage will be at very low temperatures.

Here is a link to Midnight solar's string calculator

MidNite Solar - Classic Sizing Tool.

MidNite Solar is the industry leader and manufacture of quality Renewable Energy System electrical components and E-Panels.

www.midnitesolar.com

Plugging in the numbers for your proposed panels for 3S2P the numbers are...


So, a below zero day, and your controller circuit gets exposed to 162Voc.

On the other hand, wire them for 2S3P and you get...


The important question with 2S3P is now "how many amps can your controller handle?".

BTW, I would look at other venues for your solar purchase. In my location, I can get 2000W of 245W panels for 440$. That's with local pickup. I think your panels are way overpriced.

 

[MT59918]

For a COLD environment like northern Montana, you really need to focus attention on what your solar voltage will be at very low temperatures.

Here is a link to Midnight solar's string calculator

MidNite Solar - Classic Sizing Tool.

MidNite Solar is the industry leader and manufacture of quality Renewable Energy System electrical components and E-Panels.

www.midnitesolar.com

Plugging in the numbers for your proposed panels for 3S2P the numbers are...
View attachment 50870

So, a below zero day, and your controller circuit gets exposed to 162Voc.

On the other hand, wire them for 2S3P and you get...
View attachment 50871

The important question with 2S3P is now "how many amps can your controller handle?".

BTW, I would look at other venues for your solar purchase. In my location, I can get 2000W of 245W panels for 440$. That's with local pickup. I think your panels are way overpriced.

It looks like it’s an 80A charge controller. It’s a 24v system. It looks like you have 48 in that calculator. I’ll have to look at the calculator. It looks like the 2s3p is a better way to go.

I’m in CT, that’s where the 350 panels are I can pick up. The new stuff is from northern Arizona wind and sun. The $1000 in shipping is a killer.
Are there any other suggestions for suppliers? I called 3 other places a week ago and left vmail a to check price and options and no one returned a call. Arizona were the only people who did. Times we live in I guess. I’m not interested in chasing people to give them business.