diy solar

diy solar

Determining factors for micro inverters ? BEST Panel config for a SP3000 TL LVM-ES?

B Dannels

New Member
Joined
Jul 19, 2021
Messages
38
Looking to get some used panels, to maximize a , SPF 3000 TL LVM-ES.

Not real sure if I need the (ES)? Ground mount panels, with a EG4 LiFePO4 48v battery.

My question is, what is the determining factors in using micro inverters on panels?

Thinking they were to be used for longer runs to prevent a large voltage drop, by changing to AC?

My plan, will put the panels about 200’ + from the controller/batteries. I also will have shading issues

with some trees. Also understand Micro’s help with shade? Do I need micro-inverts for this length of run?

How to Compare Wire size cost vs Micro Inverter cost?



Also looking for the best panel configuration, (Max. Watt) being cost effective when looking for used for this Growatt 3000

with a 200 foot plus length of run!



Thanks for your Time

Bill
 
Looking to get some used panels, to maximize a , SPF 3000 TL LVM-ES.

Not real sure if I need the (ES)? Ground mount panels, with a EG4 LiFePO4 48v battery.

My question is, what is the determining factors in using micro inverters on panels?

Micro-inverters are used in place of a string inverter. You would use your Growatt OR microinverters - not both.

Thinking they were to be used for longer runs to prevent a large voltage drop, by changing to AC?

No. designed for grid-tie solar.

My plan, will put the panels about 200’ + from the controller/batteries. I also will have shading issues

Do you have any better options?

with some trees. Also understand Micro’s help with shade? Do I need micro-inverts for this length of run?

Again, not if you want to use your Growatt.

How to Compare Wire size cost vs Micro Inverter cost?

Voltage drop calculator.

Also looking for the best panel configuration, (Max. Watt) being cost effective when looking for used for this Growatt 3000

IMHO, that inverter is impossible to get 4000W with its 18A PV input limit. 4000W/18A = 222Vmp - it's impossible to find a combination of panels that will hit Vmp=222V and not blow the 250V limit.
 
Micro-inverters are used in place of a string inverter. You would use your Growatt OR microinverters - not both.



No. designed for grid-tie solar.



Do you have any better options?

Not really, have other spots, maybe 1/4 the size. Thinking the longer run would be more cost effective?

Again, not if you want to use your Growatt.

Not dead set on the Growatt, picking the AIO because of simplicity, very open to other AIO's suggestions !

Voltage drop calculator.

Trust me, I tried looking at 3 or 4 different voltage calculators, some not showing 48v, talking about 2 runs?, amps?
I am not real sure about what inverter or panels I am going to use at this point! My best conclusion was 3 AWG THHN/THWN-2 Building Wire $2.05 per foot?
IMHO, that inverter is impossible to get 4000W with its 18A PV input limit. 4000W/18A = 222Vmp - it's impossible to find a combination of panels that will hit Vmp=222V and not blow the 250V limit.
I am not sure how you got the 18A PV limit? Maybe I used the wrong inverter info??
SPF3000TLLVM-48P
3000VA/3000W
Maximum solar charge current 80 amp.
Maximum PV array power 4,500 w
For whatever reason, it just seems like I can't get off 1st base! Between the inverter, panels and the wire for the run, I am totally lost as where to go next. Your input is greatly appreciated and much needed. Going back to the inverter, do you think the Growatt is a good choice for what I'm trying to do?
Thanks again for your time
 
SPF 3000 TL LVM-ES
I am not real sure about what inverter or panels I am going to use at this point! My best conclusion was 3 AWG THHN/THWN-2 Building Wire $2.05 per foot?

Without knowing the specifics of voltage and current (which panels you're using, and how the array is configured), one can't make any conclusion about the wire.

I am not sure how you got the 18A PV limit? Maybe I used the wrong inverter info??

Per your subject line:

SP3000 TL LVM-ES​


1641499647438.png


SPF3000TLLVM-48P
3000VA/3000W
Maximum solar charge current 80 amp.
Maximum PV array power 4,500 w

That's a different model than the one you referenced in the subject line.

For whatever reason, it just seems like I can't get off 1st base! Between the inverter, panels and the wire for the run, I am totally lost as where to go next. Your input is greatly appreciated and much needed. Going back to the inverter, do you think the Growatt is a good choice for what I'm trying to do?
Thanks again for your time

You have a fundamental misunderstanding. Micro-inverters are not used in conjunction with a Growatt. Micro inverters do the same thing as a growatt (inverter PV DC to AC); however, they are typically used exclusively for grid-tie.

Long runs require higher voltage (more panels in series). Partial shading benefits from parallel (less panels in series, more in parallel) as such, a 200' run with shading issues is just a bag full of buttholes. Are you sure that this is something that makes sense for you? Shading can be devastating to solar production even with microinverters.

Microinverters don't make panels perform better in shading, but they make the overall array perform better. Example:
10 panels in series. 9 in full sun, 1 shaded to reduce output by 50%. Your array would perform at about a 95% level.

On the Growatt, the one panel would contribute nothing since it would be bypassed due to underperformance, so the array would be at 90%.

Have you designed this system based on the loads, the daily energy you need, etc.?
 
Sorry about the mix-up on the inverter, MY error, cut and pasted the wrong one! Thinking the SPF3000TLLVM-48P is more like what I
was thinking I need?? Re: Have you designed this system based on the loads, the daily energy you need, etc.? To clear this up, I have NO needs,
all I have is wants. I am 75 years old, looking for something to to do, bought this place on 6.5 acres, Lots of trees (some of it on the Peace River). close to the middle of nowhere! Sold my Internet based business of more than 20 years. Probably have more money than I should! Love working on/with computers. Only Solar experience, put together a 12v system to run a Frig. and LED's in our off grid Cabin that we no longer have, 15 years ago, !

Mining Crypto is my new hobby of 2 Months. I really enjoy it because it's computer based! Solar stuff also really intrigues me.
Number 1 want's, is to run my small 700w mining rig on solar during the day. Then I want to see how long I can run it after dark!
Then I want to build another rig and see what it will take to do the same! It is so quite and peaceful out here, it'd driving me nuts!!!

No internet connection to speak of, watching YouTube (Will Prose) on my phone hotspot. Spent a while learning and setting up a wi-fi router connected to my phone. Takes care of all my current needs. 3 Computers, Alexa, Vacuum, two TV's. and runs my mining rig 24/7! :)

Done rambling on, back to my WANTS. I want to do this, but at the same time, I don't want to piss away the money. Not looking for a payback, hell we are in the middle of nowhere, I can justify the system cost for peace of mind, if we get any blackouts! :) If I were to use the SPF3000TLLVM-48P (unless you have a better suggestion) 4000w of panels and a battery, I pretty much know the cost except for the wire. I really think the long run is my only option. Choices are A, B, C, D. D is my largest area and earliest sun in the AM! B & C are much closer to the house, but Lots of trees.
I will try to attach a aerial view of our property showing my situation. Uploading sux via hotspot out here!

TKS
BIll
 

Attachments

  • SolarLocation2.png
    SolarLocation2.png
    4.2 MB · Views: 10
Assuming 200' run worst case.

Utilize 60 cell panels with a Vmp around 30V. This will get you about as high as you can go on a 145Voc controller.

18 250W panels (60 cell) in a 3S6P array. will give you about 90VDC and 50A.

At 200', 90VDC, 50A, 3awg will give you a 4.4% voltage drop.

Is 3awg readily available?
 
Well I finally feel like I am moving off 1st base, and I thank you for that!! :)

>Is 3awg readily available?
I am saying "Yes" If this one will work in regards to this application? https://www.wireandcableyourway.com/3-awg-thhn-building-wire
Picture shows 7 strands, description says 19 strands. I just found this place looking around on the web. Don't know if there is a better place??
What is your thoughts going to higher watt panels? maybe 72 cell?
Just looking for some flexibility in choosing used panels!

Thanks Again
Bill
 
72 cell panels will produce lower Vmp. Their Voc is too high for 3S, so you'll have to run 2S and need even thicker wire. You can fit 3S 60 cell panels for a higher working voltage.
 
Just checking to see, if Sunshine_eggo is still here??



Life gets in the way.... Making progress!
I got, what I consider a good deal on 12-240w USED Q-cells panels! Voc 37.5 Vmp 29.6 Isc. 8.9A. I can get more if needed! 12 was all I could carry! ☹️
He has three or four more pallets of them. They were $65 each, they came from a power company out west. They changed them out for newer/bigger ones, to get another tax break!?
At this point, I am 70% sure on getting the Growatt SPF 3000 TLLVM-48 max. 80 amp. Max. PV 4,500w. I am not really married to the idea, if you can make a better suggestion for my situation! ? Regarding what to use for wire, I selected the 3awg, because I could buy it by the foot.
Now that I really need a 250' run, I can get that length just about anywhere!
Length of run (panels to Controller is 250' NOT 200'!
Knowing that the extra 50 ft will increase the voltage drop, not real sure if the wire size would be the same?
On a lighter note, at least we know the size and type of the panels.
Appreciate ANY help you or anyone else can give, in helping with my decisions !
Thanks Again!
Bill
 
It's hard to tell from the picture, but if tall trees are the problem, could you put the panels on the North side of the pond? Seems like they would have a clear view to the south and the cable length isn't that much farther than your D spot.
 
It's hard to tell from the picture, but if tall trees are the problem, could you put the panels on the North side of the pond? Seems like they would have a clear view to the south and the cable length isn't that much farther than your D spot.
Lazy dragon, you are correct, that is kind of where I have been thinking! Need to kind of split the difference, because of the trees!
 
Back
Top