Hi everyone, I would like to know if there could be any problem with this setup for an off-grid, I want to have 10kWp of solar panels, connected to two MPPT 250/100 and the MPII 48V 5000VA 70+50A. I think it should be fine but I want to make sure, because I've seen other setups that they match approx the kWp with the inverter power. Thank you!
There isn't really a strong relationship between PV power and MultiPlus power in a DC bus system, that's more of an AC PV inverter thing.
The batteries are a more important factor. The batteries are the interface between the two, absorbing the PV charge, and supplying the inverter loads.
For a 10 kW PV array, I would be looking at least 1000 Ah at 48V of lead acid, or 10 kWh of Lithium batteries.
You may have other reasons to increase the size of the battery bank beyond that, but just to be able to absorb the potential PV power, that would be the minimum.
Thanks for your answer @Guy Stewart (Victron Community Manager). My plan is to install 4x(9,6kWh) or 6x(14,4kWh) pylontech 2,4kWh batteries.
What would be the limitation that the batteries would have for the absorption of the PV energy? For example, if the panels are producing 8kwp, are the batteries able to absorb all of that at the same time?
Each Pylontech module has a chrarge/discharge limit of 25A.
4 x 25A = 100A x 48V = 4800W of charging power
6 x 25A = 150A x 48V = 7800W
So for 8kWp of potential Solar power you should use at least 7 modules and for 10kWp 8 or 9.
Thanks @Matthias Lange - DE, I would assume that the Pylon will self-limit to 4800W charge in case that there is more available? Or it would damage the batteries?
BTW, I see that you have multiplied by 52 instead of 48 in the 6 batteries example. So they can allow up to 7200Wp. I hope it's ok for installing a few more watts (10-20% extra), as I assume this value would realistically never be exceeded, having panels not towards south 30º tilt, etc.
