Solar Panels 400ft From House....19360 KW system with 3 SMA SB 7.0-US inverters
I'm trying to figure out how to get the power from my panels back to my house, with acceptable Voltage drop.
I'm wondering if I can run DC back to house with 3 x 2 Pairs of 4 AWG aluminum then hook to inverters, or should I have a breaker box and inverters out with solar panels and run the AC back on 350mm wire?......Thanks for the help in advance....Dan
I'm wondering if I can run DC back to house with 3 x 2 Pairs of 4 AWG aluminum then hook to inverters, or should I have a breaker box and inverters out with solar panels and run the AC back on 350mm wire?......Thanks for the help in advance....Dan
Comments
Each of your 3 arrays would be connected to roughly 6500w.
Run that at something like 450v. Would leave you with about 14.5 amps to move at peak power.(per array)
A pair of 10awg gauge copper wire could do that.
http://www.calculator.net/voltage-drop-calculator.html
At ac transmission you would be transmitting at 240v
That is 80 amps at peak. 1/0 should handle that approximately 100kmils
Price your options. Will you ever need or want ac power out by the array? If so transmitting via ac maybe benificial.
So, I was trying to stay with alumninum for the 400ft long, and in order to maintain 3% Voltage drop or less, the tools were saying I needed like #250 aluminum or like 4/0 copper (which looks really expensive).
Is the 3% voltage drop the real target (as all the tools seem to say so) or can I go higher?
Here is output of the voltage drop tool..
Results
I am available for custom hardware/firmware development
Agree with all comments about sending higher DC current.
hth
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But a more realistic 65 amps 2awg copper gives a 3.39% drop
2/0 awg aluminum gives a drop of 3.28% at 80amps 240v
These are much smaller than what you thought you may need. But I am cheap and even 2awg is expensive to me.
3 pairs of 10awg cabling would do your 3 arrays.
So calculate rate of 1200ft [400x3] 2 conductors. 10awg.
Vs
400ft of 2
Only reason I see to do ac transmission is if you need ac power out that way anyway.
I am going to do an array at a similiar distance yours is. Mine will do ac transmission because I need power out there anyway.
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