This system can be used for an off-grid property or an entire house if you heat and cook on natural gas. It will be compact because of the hybrid inverter. It has a high solar input voltage, so we can wire many panels in series. You can add a generator.
As a rule of thumb, we need to be able to recharge the whole battery in one day. One day averages 3 sunhours in Houston, Texas. Two lithium server rack batteries have a total storage capacity of:
51.2V ×100Ah ×2 batteries=10,240Wh
If we have 8x 365W of solar panels, we can recharge the battery with:
10,240Wh⁄((8panels ×365W)=3.5 sunhours)
The inverter’s max input voltage is 480VDC. Let’s calculate the number of panels we can string in a series.
The solar panel specs are:
- Power: 365W
- Open Circuit Voltage (VOC): 48 V
- Short Circuit Current (ISC): 9.83 A
- Maximum Power Voltage (VMP): 39.10 V
- Maximum Power Current (IMP): 9.33 A
480VDC/((48Voc ×1.25))=8 panels in series
We can have a maximum of 8 panels in series for this off-grid hybrid inverter.
Let’s calculate the PV wire for this system if the solar panels are 100ft or 30m away from the PV input of the hybrid inverter.
We can see that we need a minimum of 16AWG (1.5mm²) wire. Since no 16AWG PV wire is available, we will use 12AWG (4mm²).
This system has a shunt that monitors the battery’s state of charge in Ah of %. You have to calibrate it in the beginning, but that is easy.