Some questions about this rule to those who understand all the implications,
Is the PV array size, for the purpose of calculating this rule out, the STC rating of the array or the NMOT rating (more realistic real world performance)? I am guessing most would say use the STC rating but can we safely use the NMOT rating or not? Does Victron say anything about this? We all know we dont get the rated power of the PV panel, so why calculate battery size based on a wattage we will never achieve?
For example, say a PV array of 60 panels at 450w.
In STC terms this is 27 kWp (60 x 450 = 27000). In NMOT terms its 20.3 kWp (60 x 338 = 20280)
So if we follow the 1.5KWp PV to 100 Ah lithium rule for the STC rating of this array it would be ;
STC PV 27 kWp / 1.5 kWp = 18 | 18 * 100 Ah = 1800 Ah | 1800 Ah x 50 V = 90 kW battery .
So if we follow the 1.5KWp PV to 100 Ah lithium rule for the NMOT rating of this array it would be ;
NMOT PV 20.3 kWp / 1.5 kWp = 13.5 | 13.5 * 100 Ah = 1350 Ah | 1350 Ah x 50 V = 67.5 kW battery.
Thoughts ?