Using arduino to drive a mosfet to limit the max power of a solarpanel.


Me again with probably an other stupid question.

I have a 125 PeakWatt grid tie inverter (18-38v). (actually I have 3 of them) I am thinking of using a 170 pw 35v solar panel.

Right now the grid tie inverter is hooked to a very old 120 pw panel which never does more than 65 pw and drops to 30 watts when the sun is not directly shining on it and back to 15 when it is a little cloudy.

So I think if I buy the 170wp panel that maybe 5-10% of the time it delivers more that 125 pw. the rest of the time it is less than that and I am in the safe zone. I found a few used ones for only 32 euro's a piece and I really want to use the inverters I have.

I recently learned that when dropping voltage you need to burn/dissipate unwanted energy or use a buck converter.

What I think I know now is that I could limit the power coming from a source simply by using pwm and reduce the duty cycle to limit power.

So if I hook a mosfet (Like the IRLZ44N) to an arduino and can measure the current and voltage going to the inverter I could make sure that when the power rises above say 120 pw I use pwm to make sure the power does not go higher?

The only limits here are the power that the Mosfet and the current sensor can handle and should be a faily simple project right?

Or am I missing something important again?