Room to expand?

[darrenbeau1]

Would buying an inverter that is higher than the planned production of my solar panels cause a severe drop in efficiency?
I'm considering buying a 15kw inverter with 7/8kw worth of production with intent to add the remaining 7/8 kw as a future expansion.
The inverter I'm eyeballing is a solaredge 15kw with optimizers on the panels if that makes a difference.
Install is residential and the first connect (anything under 10kw) is free with my utility to connect so I won't get double charged.
All help is appreciated!

 

[gnubie]

No, it won't cause severe drop. You are looking at the 3 phase unit? The peak efficiency looks pretty good so I don't think you have anything to worry about at all there. If you have any questions about it probably best to refer to the place you are buying from or having it installed by.

 

[darrenbeau1]

I appreciate your response! Yes the three phase is the one I'm looking at. That I will do, thanks!

 

[JeepHammer]

What I found when I stepped up,
See if it's one big transformer or smaller transformers that 'Cascade' as load increases.

Single big transformer units will REALLY lean into a Load, but they losses are full time no matter what the load on the inverter is.
The smaller, multi-transformer units take a second to 'Ramp Up' to lean into load, but they have MUCH lower idle or lower Load losses.

The same is true with big split phase (heavy 240 volt) inverters,
My first 240 inverter was supposed to be 'Bullet Proof', virtually indestructible, and it's still here and still works 15-16 years later,
But it sucks about 20% of the rated amps full time!

It's replacement losses are small and go up as load increases, topping out about 16-18% of full load.
It can idle along at 1-2% of rating output, a HUGE difference!

I actually though my solar/battery system was screwed up somewhere, I try to push a machine shop on (mostly) solar.
I was building heated dies for a vulcanizing/lamination press and they had very specific resistance heating elements in them, I plugged them into my inverter, tracked input and output, and was DUMBFOUNDED by the results!
I pay a LOT more attention to losses now.

 

[Supervstech]

Would buying an inverter that is higher than the planned production of my solar panels cause a severe drop in efficiency?
I'm considering buying a 15kw inverter with 7/8kw worth of production with intent to add the remaining 7/8 kw as a future expansion.
The inverter I'm eyeballing is a solaredge 15kw with optimizers on the panels if that makes a difference.
Install is residential and the first connect (anything under 10kw) is free with my utility to connect so I won't get double charged.
All help is appreciated!

15KW inverters are great, but 8KW panels can easily out produce the demand from one...
Unless you are DRAWING 15KW all day.

8KW panels can produce 48KWh energy into the battery bank. How much KWh do you use a day?