Solar Inverter

If a 4 kilowatts inverter needs 80 watts of electericity to convert, can i use only an 80 watts Solar Panel ?
I’ve seen people installing bigger Solar Panels, than their inverter requires, why ?
A 80 Watts solar panel, assuming 100% efficiency, can provide max 80 Watts. That’s good enough for one light bulb.
I am sure you need more power than that…
Total Power In = Total Power out + Losses