Let's say your panels could produce 95% of nominal, 3 hours a day, 3 months of the year when the sun is in the right spot. That's 4275W, or 75 over. 0.075 * 3

Let's say your panels could produce 95% of nominal, 3 hours a day, 3 months of the year when the sun is in the right spot. That's 4275W, or 75 over. 0.075 * 3 * 90 is 20kWh you're leaving on the table per year. So yeah the payback time for the more expensive one would be never. I'm seeing price differences from 4200W to 5000W inverters be more like 10-70€ though: https://www.alma-solarshop.com/10-solar-inverters?q=Inverter+type-Grid+inverter-Hybrid+inverter/Power-4200W-5000W https://www.alma-solarshop.com/10-solar-inverters?q=Inverter...