Hi Jason,
Thank you this is very helpful.
In my situation, are these correct statements?
- There is no value to having an oversized solar inverter unless plans for expand are imminent.
- If my max consistent output (output that is consistently reached on sunny summer days) with all the considerations you note below is around 7kw then my solar inverter should be “around” 7kw. A little higher or lower will have no significant input.
- A 10 kw solar inverter (if I have no plans for further expansion) is overkill. I am paying extra for capacity that I am never going to use.
- A 7kw solar inverter will also be highly efficient.
My only remaining questions are:
- What is the practical efficiency downside if I have a 10kw dollar inverter? For example, does my efficiency at peak output get reduced to 90%? 80%? 70%?
- What are the efficiency measures at lower output? For example, in winter in Maine, days are short and sun is scarce. Does a larger solar inverter mean I am less likely to take full advantage at lower output? This is important because winter is when I am most likely to lose power from the grid.
I really appreciate your patient help. The contractor that is adding to my array ordered a 10kw solar inverter and I want to make sure I understand any negative implications before I consider installing a solar inverter this big.
Thanks
Fran