DyslexicDancer
New Member
- Joined
- Aug 3, 2022
- Messages
- 27
I'm going to be setting up an off grid power system and had a few questions on panel string size at low temperatures
I'm using 12 Sunpower E20-330-COM-MLSD panels with the following specs
330W
Power Temp Coef. −0.35% / C
Impp 6.04A
Isc 6.52A
Current Temp Coef. 2.6 mA / C
Vmpp 54.7V
Voc 64.9V
Voltage Temp Coef. −176.6 mV / C
I'm using a SPF 3000TL LVM-48P Inverter which has a maximum Voc of 145V
If I wire two panels in series I should have a Voc of 129.8V @ 25C
The all time low temp record in my area is somewhere around -25C
I found an online calculator (https://footprinthero.com/solar-panel-voltage-calculator) to figure out my maximum Voc and it is showing 138.8V with the panel specs given above and that would keep me under the 145V limit of the inverter
Just wanting to make sure I'm understanding this correctly and that the online calculator is correct, because if I run the math myself I come up with a Voc of 147.46V, but then I was never great at math, maybe the calculator is factoring in voltage line loss which I have not done?
Any help would be appreciated
I'm using 12 Sunpower E20-330-COM-MLSD panels with the following specs
330W
Power Temp Coef. −0.35% / C
Impp 6.04A
Isc 6.52A
Current Temp Coef. 2.6 mA / C
Vmpp 54.7V
Voc 64.9V
Voltage Temp Coef. −176.6 mV / C
I'm using a SPF 3000TL LVM-48P Inverter which has a maximum Voc of 145V
If I wire two panels in series I should have a Voc of 129.8V @ 25C
The all time low temp record in my area is somewhere around -25C
I found an online calculator (https://footprinthero.com/solar-panel-voltage-calculator) to figure out my maximum Voc and it is showing 138.8V with the panel specs given above and that would keep me under the 145V limit of the inverter
Just wanting to make sure I'm understanding this correctly and that the online calculator is correct, because if I run the math myself I come up with a Voc of 147.46V, but then I was never great at math, maybe the calculator is factoring in voltage line loss which I have not done?
Any help would be appreciated
Last edited: