Comment by spockz
9 hours ago
On my case I have 4500Wp of panels. The inverter is sized at 4200W. The next step up 4800 or 5200 was twice as expensive adding about €600. Not sure if I ever would have made that back. I hit the maximum only a few weeks in spring.
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...