Power flow and priorities in solar hybrid system
I tried looking all over the internet for an answer on the power flow in DC-coupled grid-tie systems with battery back-up. All sources claim that if PV production > load then the surplus will go to charge the battery. I'd like to know why it is like that and not the opposite, meaning why isn't the battery primarily fed and the surplus sent to the loads. From what I understand, the charge controller comes directly after the PV array and is not considered a load, but rather the batteries are. The CC basically just dictates the voltage at which the batteries should be set depending on their state of charge. I think it does matter how the power flows in that system since according to most sources, PV primarily feeds the loads and any excess is used to recharge the batteries. What I'd like to know is how they came up with that statement. Could it be something between the CC and the Inverter or maybe something related to basic electric circuits theory that I must have missed?
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