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Calculating MPPT size ... and then seeing what these little blue boxes cost. Sigh ...

Victron has a very nice calculator that allows you to enter the PV panel specifications and allows you to play around with the number of panels in series and parallel.

I learned one thing today from this. MPPTs will be another factor to consider when you decide on the number of PV panels you are installing. A simple example is that I will require the same number and type of MPPTs if I install 20 panels or 24. It becomes a "cost of equipment" optimisation game where the cost of panels can be played off against the cost of the MPPTs and the energy you require.

I also learned from one distributor today that quite a few people blow their installed MPPTs because they did not take into account the Voc voltage spiking effect when a PV panel sitting without sunshine at minus 0 C, suddenly start generating electricity when the sun energizes it.

In addition he also mentioned installer who do not take the phenomenon named cloud albedo effect, into consideration when choosing a MPPT.

Never realised that these two factors can actually create the holy smoke.