Please give me your feedback on my system. TYYYY

[konst85]

Hello, I am fairly new to DIY solar. I purchased the 3kW Stackable 48V 150VDC 80A Off-Grid Inverter by Growatt that Will recommended. I purchased the JK48V100 Server Rack LiFePO4 51.2V 100Ah 5120Wh Smart BMS Rechargeable Lithium Iron Phosphate Battery. Now I am trying to pair this with 3 solar panel's for an off grid system. Attached are the specifications for the solar panels. I want to make the system as simple as possible so I want to arrange the panels in a series. I used the calculator that will recommended but cant decide if the panels are correct and will work in a series with the inverter.

Im open to all feedback. I am here to learn. THANK YOU!! Or if you think another panel will work better let me know. I can pick these up new for $165 each.

 

[sunshine_eggo]

First, did you establish that the inverter, solar and batteries will meet your electrical needs?

Second, if the inverter you purchased has a 145Voc PV input limit, and you are not in a cold environment (< 0°F), you should be able to series three of those panels.

 

[konst85]

@sunshine_eggo Thank you for your feedback. The system is in Sacramento CA. It almost never snows here. Lowest temp on record was 17degrees F. I want to power a 300 watt computer.

 

[rmaddy]

Assuming a 5120Wh battery and 80% DOD you get 4096Wh. Your 300W load with inverter inefficiencies is about 350W. So you can run your computer for 4096Wh / 350W = 11.7 hours before you need to recharge the battery. This assumes a constant 300W load from the computer.

With 885W of solar and 5 good hours of sun each day you have 4,425Wh of solar on a good summer day. That would be enough to recharge the battery each day but not enough to recharge the battery fully and run the computer during the day. And none of this deals with a cloudy day or two.

So depending on how many hours you actually use the computer each day and the time of day that you use it you may need more battery and/or more solar. It would be a lot cheaper to double your solar panels than buying a second battery.

 

[konst85]

@rmaddy Thank you for your response. If this was your system can you please give me an example of what kind of solar panel you would go with? If you wanted to keep it simple and arrange panels in a series.

 

[rmaddy]

Assuming the max PV input voltage of your all-in-one is 145V (please verify what it really is) then 3S is the max with the panels you show. For 6 panels I would put them in 3S2P. That's a simple setup. You just need one pair of MC4 Y-connectors to join the two strings together.

Since your all-in-one appears to support 80A max battery charge current and you have a 48V system, you can have up to 4kW of solar panels.

Given the 145V max input voltage and coldest temperature you might see, you should be safe with any solar panel that has a Voc of 40V or less if you want to have 3 in series (and any number in parallel). That likely limits your panels to 300W, maybe 310W depending on the panel. So you can create 900W strings and parallel up to 4 such strings. Maybe even a 5th string and set them up to point in different directions to maximize your solar from sunrise to sunset. But that's likely a lot more than you need for one 300W load.

 

[konst85]

Assuming the max PV input voltage of your all-in-one is 145V (please verify what it really is) then 3S is the max with the panels you show. For 6 panels I would put them in 3S2P. That's a simple setup. You just need one pair of MC4 Y-connectors to join the two strings together.

Since your all-in-one appears to support 80A max battery charge current and you have a 48V system, you can have up to 4kW of solar panels.

Given the 145V max input voltage and coldest temperature you might see, you should be safe with any solar panel that has a Voc of 40V or less if you want to have 3 in series (and any number in parallel). That likely limits your panels to 300W, maybe 310W depending on the panel. So you can create 900W strings and parallel up to 4 such strings. Maybe even a 5th string and set them up to point in different directions to maximize your solar from sunrise to sunset. But that's likely a lot more than you need for one 300W load.

Thank you!