New Solar Setup in the Arizona Desert

[AZ Off-Gridder]

Hey there fellow Solar lovers. I’m in the planning phase of my off grid solar setup and this is fortunately my 2nd time around the block. In late 2019 many of you helped me (Arizona Off-Grid, lost my account login) build a very budget very simple build and I lived off grid in a camper trailer for 9 months and I loved every bit of it. Life circumstances changed and I sold the property and entire setup…. Long story short I’m starting over now and this time I have a better understanding, and a better budget!

Just for some more background information The off grid home will be a tiny house made out of company built shed. 14ftx32ft insulated with spray foam.

(Edited after learning more…)
Im looking at getting 12 250w SanTan T Series (used snail trails they call them, small cosmetic blemishes on used panels but all tested and pass CC) they sell for $50 each!
Panel details: 60 cell Polycrystalline
250W. VMP 30.3V. MPC 8.27A
Wired into 4 parallel series of 3
Giving me 90.9V at 33.8A = 3,007W -15% for lose from used panels (Thanks Bvillebob!!) so 2,555wh from 12 panels
15.3kwh per day. Not sure if this will be large enough for this setup after learning about my calculation errors. Thoughts?

I want to pair this with 3 of Signature Solars EG4 48V 100AH Batteries. Wiring these big batteries in parallel. For a total bank of 15.36KWh. Or how does the Jakiper battery compare?? Looks very similar in specs….

Next is the inverter, after having an all in one unit before I really loved it, so I want one for this build. I’m looking at the Growatt 48V 3000TL LVM 3kW or
Renogy 48V 3500W. If anyone has any input to what one would be better for my setup, I do know the EG4 battery uses a Growatt BMS is there any benefit to that matching up with the Growatts Inverter?

Please let me know if my math is wrong and if this sounds like a balanced setup. It would cost me around $6,500
And I know this post is lacking what my usage is, that’s because I hate calculating it, that’s something I still struggle with I’ve done so many calculations and adding up. And my numbers are always so high I just know they’re inaccurate. So instead I’m laying out the proposed build, and y’all tell me if you think it’s solid and would run a tiny home in the Arizona High desert. Or maybe if need be we can work out my power consumption needs. Thanks for reading yall.

 

[Bvillebob]

Your math is wrong in that you're using Voc, not Vmp, same for amps, for calculating power.

They're (theoretically) 250 watts panels, 12 of them will not give you 3,929 watts, theoretial max is 3,000 watts. I have 40 of them installed, same panels, realistically I've seen about 200 watts out of each of them. They're used and somewhat degreaded, but still great panels for the money. For planning purposes, I'd suggest figuring on getting about 2500 watts out of 12 of them. You may get lucky and get more, you may not, it's a gamble with used panels. As I said, I like them, they're doing a great job, but be realistic about their output capacity.

 

[AZ Off-Gridder]

Your math is wrong in that you're using Voc, not Vmp, same for amps, for calculating power.

They're (theoretically) 250 watts panels, 12 of them will not give you 3,929 watts, theoretial max is 3,000 watts. I have 40 of them installed, same panels, realistically I've seen about 200 watts out of each of them. They're used and somewhat degreaded, but still great panels for the money. For planning purposes, I'd suggest figuring on getting about 2500 watts out of 12 of them. You may get lucky and get more, you may not, it's a gamble with used panels. As I said, I like them, they're doing a great job, but be realistic about their output capacity.

Thank you! I appreciate your honest opinion, and personal input from using these panels it’s very helpful to me. I’ll get more panels. And I’ll correct my math for the panels wh production, thanks. Do you use an all in one inverter/charge controller? And are you also 48v?

 

[Bvillebob]

If you're going to be using this system as your basic power supply, I'd really suggest looking at buying better quality equipment. The Growatt stuff has been having some issues, and Renogy doesn't have a very good reputation. In the big picture, stepping up to some first rate equipment won't cost that much more and will be much more reliable. For my system, i'm using Midnite Classic charge controllers and Samlex EVO inverters, really well made, great customer support and service and highly reliable. Lots of other good stuff, like Victron of course, probably the most popular, Magnum, Shneider, etc. I'm not associated with them in any way, but I just recently discovered a vendor that gets little recognition, DonRowe.com, great prices on inverters.

 

[Bvillebob]

My system is 24v, just started out that way and once you've got the investment it's easiest to stay that way. I don't use much power compared to some people, I have a 4KW and a 2KW inverter, 20KWhour of lead acid batteries I started with and added 45KWhour of lithium batteries last summer from cells I bought and built up. At that level the 24v is working fine.

 

[AZ Off-Gridder]

I’ve made the calculation changes to my original post, thanks again Bob!

 

[JoeHam]

I agree with Bob but if you really must stay with a budget price AIO take a look here :

My DIY Experience with a MN3024DIY Hybrid Inverter

After viewing my cabin solar system, a friend asked me to help him plan and install a similar system for his remote cabin. My system consists of 2,400 watts of solar panels, a Magnum MS4024PAE inverter/charger, a Midnite Classic, a 10,800-wh Trojan T-105 battery bank, and a 11-kw diesel...

diysolarforum.com

Still chinese made but US based support. No personal experience.

I also like Don Rowe but here is a place in AZ with 5% off your first order :

MidNite Solar DIY Series MN3548DIY Inverter & Charger

Note: This model has been succeede by the MidNite MN5048DIY

www.solar-electric.com

I have a couple of the San Tan panels powering a small off grid shipping container less than 10 miles from San Tan Solar.