Sizing an inverter

I have a 3kw SolarEdge inverter with approximately 4.2 kw maximum production from my current panels. Because of this, actual usable production tops out at 3 kw. I am adding 4 more 300 watt panels to my array in the next few weeks. That would bring my maximum production to about 5.4 kw.

I am going to replace/upgrade my inverter. My question is . . . what is the right size? and . . . what are the advantages and disadvantages of getting an oversized inverter (say 10kw)?

Hi Fran,

The right size inverter is not a simple question as it is based on your consumption and usage patterns and how efficient your house is. What is your daily or monthly usage in kWh?

Try using this tool to help -

Hi, I am not sure I understand what consumption and usage patterns have to do with the size of the inverter. I mean I understand how that would help you figure out how many solar panels when designing a system . . . and . . . therefore, that would influence which inverter and what size.

I guess my question is . . . based on the maximum output of one’s solar array . . . what are the considerations in sizing the inverter? Should it be sized right around that maximum output? What are the advantages or disadvantages of sizing it bigger than that? For example, if my maximum solar output is 5.6 kw . . . should I get 6kw or 10 kw inverter? Thanks.