If I have a 13kW system, will a 5kW export limit overheat the inverter or damage panels?

Question :

I've been told to get the biggest solar system possible, however between 11am and 3pm on sunny days, when we aren't using much power at home, and the grid will only take 5 kW, isn't the power wasted?

Is the excess energy the panels are producing "dumped" somehow?

Did I read correctly it is possibly converted to heat at the inverter, or is put back into the panels?

I'd like to understand how this excess energy is disposed of?

I'm concerned this this "burning off" of excess energy might damage to the inverter or panels, or reduce their effective life?

Answer :

Export limiting is not a big deal, so don't be too worried about "losing" extra energy sometimes. The economic value of export at 5c/kWh is negligible compared to having a decent amount of your own solar energy available, saving 35c/kWh for extended hours of the day.

If there's waste then it's best described as wasted potential, (ie that's energy you could store in a hot water service, EV or battery) It's not actually wasted yield.

When your solar is throttled by the export limit setting there's no work being done nor extra heat generated.

To use a water analogy, when you close a tap the flow (current in amperes) stops and the pressure (voltage) in the pipe rises until its equal to the mains water supply.

When you hit 5kW of export, around 22amps at 240VAC... the inverter simply doesn't pass through any more energy.

The DC voltage supplied from the panels rises and the DC current slows, but nothing else goes on.

If you turn the kettle on (and there's enough sunshine) the inverter simply ramps up and delivers more current until either the sun fades or the water is boiled.