starmage Posted January 21, 2021 Posted January 21, 2021 I have 6x355 panels and a Victron BlueSolar 150/45 MPPT (max 2600w input from panels). Although my summer production is basically enough most days(basically +- 13kW production), my winter production is almost half that at arounf 7.5kW. I now want to add an additional 6 panels to specifically increase my winter production. What is best : 1. add another 150/45 MPPT or 2. Replace the current MPPT with a larger model e.g. 150/70 (max 4000w) Quote
wolfandy Posted January 21, 2021 Posted January 21, 2021 51 minutes ago, starmage said: 1. add another 150/45 MPPT or 2. Replace the current MPPT with a larger model e.g. 150/70 (max 4000w) Adding a 2nd MPPT would give you the option to have the new panels face a different direction (e.g. capturing the early morning sun) If you replace your current MPPT, I would go for a 250/XX model. This allows you to connect more panels in series, which result in a longer solar day Maybe play around a bit with the PVWatts Calculator and see which direction will give you the best yields? Gandalf 1 Quote
starmage Posted January 21, 2021 Author Posted January 21, 2021 Forgot too add - its a flat IBR roof, so there is only 1 direction (direction and pitch is excellend for summer >85% efficientcy, where as in winter the efficiency drops to about 60%) Quote
wolfandy Posted January 21, 2021 Posted January 21, 2021 9 minutes ago, starmage said: so there is only 1 direction In that case I would upgrade to a 250/XX model and re-wire to put more panels in series. Are you currently running 2S3P? If yes, you could then add your new panels to make 4S3P - which means you would not even need to pull any new wires or add any new combination boxes (obviously assuming that your current wires/boxes can handle the new config) Quote
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