When my solar panels are sitting in the sun all day but the battery is full, where does the extra power go?


Edit: I should mention it’s a boat system so it’s not grid tied

In: 510

Usually, solar panels are set up such that excess power is put back into the grid. The systems are also able to simply shut off and not produce any power at all, but that’s wasteful.

Assuming your system is not tied to the grid, no extra power is generated. Once the battery is charged the controller will not be allowing any power into the battery. This results in an open circuit on the panels, as if they weren’t connected to anything at all. The voltage across the panel will increase until the incoming sunlight balances the voltage, and the incoming sunlight power will turn into heat just like if you sat a black object in the sun.

There’s a battery in solar panels that can be full? TIL

If you have a grid-tie system, depending on where you live– the electric utility buys power from you when you generate more power than you use.

Solar panels have U I curve very “straight” meaning open circuit voltage isn’t thet much higher than MPP point meaning you can disconnect them from inverter and they will be fine