diy solar

diy solar

About to take the plunge...

MJSullivan

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Jul 16, 2021
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About to take the plunge on purchasing a "DIY" solar PV system from Northern Arizona Wind & Sun. This is the layout I gave their sales department for my particular situation. Other than a total price I haven't had much feedback from them on specific details. Note that these panels are being mounted on an old timber-frame (post and beam) barn, so there are no rafters, only purlins. By my count there appears to be a need for 36 QuickBolt mounts to hold everything together (as shown in the diagram). Additionally I'm not 100% sure where the best place for mounting the combiner -- currently I assume it should be in the attic near the PV panels but perhaps it can be located in the basement near the inverter? Anyway, hope to hear from some of you on this forum as to the veracity of this design. Feedback welcomed.

Michael
 

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Depending on the voltage of the panel wiring. My panels are wired to produce 300V. My combiner box is 50ft from the panels, next to the charge controller. In any case l don't know why you need the combiner box in the attic. Of course there is practically no information about the system in your post, that would allow to give sound advice.
 
Depending on the voltage of the panel wiring. My panels are wired to produce 300V. My combiner box is 50ft from the panels, next to the charge controller. In any case l don't know why you need the combiner box in the attic. Of course there is practically no information about the system in your post, that would allow to give sound advice.
Diagram below. The initial plan is to use the PV+Battery primarily as a UPS for critical loads for the time being. However, in the future I can imagine adding additional strings and larger battery to power EVs and possibly a heat pump. The thought I had was to to avoid having to run future wiring all the way down to the basement. Additionally, I was under the impression that the DC surge protector should be as close to the PV panels as possible, but perhaps that is not necessary.
OutBack RSI Remote Shutdown3.1024.jpg
 
Wow, you are purchasing a very complete and sophisticated system. Appears that each one of your panels has it's own monitoring and shut off system. On top of it rapid shut down. There are protections all over and latest battery technology. I still don't see why you should not be able to install the combiner box where it best suits you. However, l need to admit that this is way to complicated of a setup for me to give reliable advise. Personally l prefer simple. No remote monitoring, no wifi, no constant software updates etc.....
My system is bare bones. 10500W of solar power, 3 strings 320V each, combiner box, 300V charge controller to charge a battery bank of 192V (16 12V/250AH Gel batteries connected in series). Single phase 10KW inverter from 192VDC to 120VAC. Couldn't better happier. On a sunny morning my batteries are full at 7:30AM, on a cloudy day by 9:AM and on a rainy day by 11:AM. Highest discharge l have experienced was 3% (201V).
Anyway, sorry to be of no help to you. ?
 
Wow, you are purchasing a very complete and sophisticated system. Appears that each one of your panels has it's own monitoring and shut off system. On top of it rapid shut down. There are protections all over and latest battery technology. I still don't see why you should not be able to install the combiner box where it best suits you. However, l need to admit that this is way to complicated of a setup for me to give reliable advise. Personally l prefer simple. No remote monitoring, no wifi, no constant software updates etc.....
My system is bare bones. 10500W of solar power, 3 strings 320V each, combiner box, 300V charge controller to charge a battery bank of 192V (16 12V/250AH Gel batteries connected in series). Single phase 10KW inverter from 192VDC to 120VAC. Couldn't better happier. On a sunny morning my batteries are full at 7:30AM, on a cloudy day by 9:AM and on a rainy day by 11:AM. Highest discharge l have experienced was 3% (201V).
Anyway, sorry to be of no help to you. ?

In Massachusetts, Rapid Shutdown (UL 3741) is required. Which as you say vastly complicates things. I'll do most of the grunt work myself for this project and hire a certified electrician to wire everything up to code and commission the system. I'll probably keep the combiner in a closet directly under the attic floor so as to keep the combiner as close to the PV panels as possible, as per the attached diagram from Outback.

Outback RSI layout.jpg
 
Yes, l can see combiner box within 1p ft of panels. I am on an island in Panama, non of the over the top regulations. This makes solar very affordable.
I bet for the price of your system l could power 5 houses where l am. Of course not with Outback and your battery packs.

Good luck
 
I have little choice— the local inspector will not approve a PV install unless it has complete documentation. Nor will any licensed electrician work on a project that is not to code. In Massachusetts, that means NEC 2020 and UL 3741. So those of you berating the “coastal elites” haven’t a clue — everything costs significantly more “here” than “there”. We have to pay. No way around it. And in the end, everyone benefits as we are the guinea pigs for the rest.
 
On more thing...

I'm about the take the plunge and purchase a "DIY" Outback 4048a system, which meets my current "critical loads only" requirements nicely. The kit consists of the following:
  • (12) REC Alpha Series 370 Watt PV panels
  • (2) Fortress eFLEX 5.4kWh batteries
  • (1) Outback FPR-4048A-300AFCI pre-wired inverter/charger with FLEXmax 100 AFCI charge controller
However, if in the future I were attempt to to double my capacity by adding another (12) PV panels and another (2) eFlex batteries would it be wiser to bite the bullet now and go for an 8048a system (presumably with one inverter un-used for the time being)? Or is it relatively straightforward to add another 4048a to my current system (or alternatively, update my 4048a to an 8048a)?

The total for all the proposed items is not inexpensive (for me), but "upgrading" to the 8048a now would merely be incremental.

Thoughts?

Michael

P.S. attached is the layout of the core components in my (rather tight) basement. I've allowed room for a 2nd 4048a to the right if necessary

Basement layout2.1200.jpg
 

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Nice looking plan.

My understanding is that you can turn a 4048 into an 8048 pretty easily, just drop in the second inverter and maybe a control board? But, I'd verify that with either your vendor or Outback.
 
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