rick86
New Member
- Joined
- Mar 6, 2022
- Messages
- 4
Hi all,
I just found this awesome community and have been searching the threads. Great info here but I can't find answers for my specific situation. I'm trying to build the system Will talks about in his video at:
I don't have any experience designing or building solar power systems so I'm trying to learn as I go, spend money wisely and not get myself killed in the process.
I'm trying to build an "off-grid" system for my home in case the power goes out. I'd like to be able to charge my Nissan Leaf during the day when the sun is out and also top off the LiFePO4 battery so that it's available during the day AND the night for small loads like lights, cell phone charging, laptop, hot plate, TV, etc. I'd like to be able to do this in situations where there's zero grid power available. I live in southern Nevada so I get plenty of sunlight.
This is what I have so far:
1 Pro Version 48V LiFePO4 Battery
1 Growatt 48V SPF 3000TL LVM inverter
14 Trina 72 Cell 330W Solar Panels (45.8V voc)
The charger for the Nissan Leaf is as follows:
input: AC120V 12A 60Hz
output: AC120V 12A 60Hz
I thought I could set up 12 panels 3s4p on ground mounts. That would give me 990w and 137.4 voc in each parallel circuit. The Growatt's max solar panel array voltage is 145VDC and the max solar array wattage (for the 48v model) is 4500W.
When I plugged the numbers into the calculator at:
www.solarchargecontrollercalculator.com
I realized that I don't know the values for:
Panel STC
Max power current Imp(A)
Temp coefficient of Voc
Temp coefficient of MPP
The specs for the solar panels are at:
https://watts247.com/product/deal-trina-72-cell-330w-solar-panel-1/
but I can't find those specs required by the calculator.
By entering the values that I know and leaving the default values in the other fields of the calculator, it says that my charge controller (which is in the Growatt) needs to be able to handle 150.4V (50.1V max voltage per panel at low temp). Since that exceeds the max panel array voltage of the Growatt, does that mean that 3s4p isn't an option with these panels?
Also, I know I need a combiner box but I don't know anything about them. I was looking at some that were 4 string with 15A fuses and 63A circuit breakers. It doesn't seem like this would be enough but I'm not sure.
And the last question is, what kind of OCPD should I get for each of the parallel strings?
Sorry for so many questions in my first post. Any help you can provide would be greatly appreciated.
Rick
I just found this awesome community and have been searching the threads. Great info here but I can't find answers for my specific situation. I'm trying to build the system Will talks about in his video at:
I don't have any experience designing or building solar power systems so I'm trying to learn as I go, spend money wisely and not get myself killed in the process.
I'm trying to build an "off-grid" system for my home in case the power goes out. I'd like to be able to charge my Nissan Leaf during the day when the sun is out and also top off the LiFePO4 battery so that it's available during the day AND the night for small loads like lights, cell phone charging, laptop, hot plate, TV, etc. I'd like to be able to do this in situations where there's zero grid power available. I live in southern Nevada so I get plenty of sunlight.
This is what I have so far:
1 Pro Version 48V LiFePO4 Battery
1 Growatt 48V SPF 3000TL LVM inverter
14 Trina 72 Cell 330W Solar Panels (45.8V voc)
The charger for the Nissan Leaf is as follows:
input: AC120V 12A 60Hz
output: AC120V 12A 60Hz
I thought I could set up 12 panels 3s4p on ground mounts. That would give me 990w and 137.4 voc in each parallel circuit. The Growatt's max solar panel array voltage is 145VDC and the max solar array wattage (for the 48v model) is 4500W.
When I plugged the numbers into the calculator at:
Solar Charge Controller Calculator
Panel STC
Max power current Imp(A)
Temp coefficient of Voc
Temp coefficient of MPP
The specs for the solar panels are at:
https://watts247.com/product/deal-trina-72-cell-330w-solar-panel-1/
but I can't find those specs required by the calculator.
By entering the values that I know and leaving the default values in the other fields of the calculator, it says that my charge controller (which is in the Growatt) needs to be able to handle 150.4V (50.1V max voltage per panel at low temp). Since that exceeds the max panel array voltage of the Growatt, does that mean that 3s4p isn't an option with these panels?
Also, I know I need a combiner box but I don't know anything about them. I was looking at some that were 4 string with 15A fuses and 63A circuit breakers. It doesn't seem like this would be enough but I'm not sure.
And the last question is, what kind of OCPD should I get for each of the parallel strings?
Sorry for so many questions in my first post. Any help you can provide would be greatly appreciated.
Rick
