Question about SolarEdge inverter sizing and clipping

[Jeff72]

I didn't say that...

You ask if there was truth in the installers statements.

from what we are seeing and from JPMs calculations you are seeing pretty little clipping and you would lose the EV charger if you changed.
You can use PVWatts to calculate the production with a 1:1 inverter to DC ratio and see the difference as he has done

Thanks for the reply. I do not think I will use the EV charger as the inverter is mounted outside my house to the electric meter box far from my garage. My electric provider does 1 to 1 metering too so I do not think I will need a solar EV charger since I can use the electric grid provider as my "backup battery". I'll have to have a circuit run to the garage from my internal panel, though, for a future electric car...if I go that route in a year or two.

I am not familiar with PVWatts. I know that JPMs output seemed to show that there wasn't a major increase going from the 7600 W inverter to the 10,000 W inverter, it seemed. But, it does seem like there can be some increase there over the 7,600.

I still am not sure what to do. However, I've left a note with my installer asking if they could replace the 7,600 inverter with a 10,000 inverter. This may be an issue for them but I will see what they say.

Any other advice would be appreciated.

[nwdiver]

Any other advice would be appreciated.

I have a 4.5kW array on a 3.8kW inverter in SE NM that I've seen clip <5 times in a year. Panels lose ~0.5%/C so on a warm day 4.5kW is really ~4KW and on a hot day ~3.5kW. You may not get much more output by upgrading to a 10kW inverter.

For Illinois PV Watts is estimating a 32kWh/yr increase from a 7.7kW inverter to 10kW inverter....

[J.P.M.]

I know that JPMs output seemed to show that there wasn't a major increase going from the 7600 W inverter to the 10,000 W inverter, it seemed. But, it does seem like there can be some increase there over the 7,600.

Yea, to the degree my misuse of PVWatts makes any sense, something like about 0.6 % increase in annual output for a 10 kW inverter over the 7.6. That was the purpose of the exercise.

[macaddict]

Thanks for the reply. I do not think I will use the EV charger as the inverter is mounted outside my house to the electric meter box far from my garage. My electric provider does 1 to 1 metering too so I do not think I will need a solar EV charger since I can use the electric grid provider as my "backup battery". I'll have to have a circuit run to the garage from my internal panel, though, for a future electric car...if I go that route in a year or two.

I am not familiar with PVWatts. I know that JPMs output seemed to show that there wasn't a major increase going from the 7600 W inverter to the 10,000 W inverter, it seemed. But, it does seem like there can be some increase there over the 7,600.

I still am not sure what to do. However, I've left a note with my installer asking if they could replace the 7,600 inverter with a 10,000 inverter. This may be an issue for them but I will see what they say.

Any other advice would be appreciated.

If you are not using the EV charger part and are already using a line side tap, I would replace the inverter with a larger one.

[macaddict]

or switching from using main panel to doing lineside tap ($1k?)

Why would a line side tap be more expensive? If anything it is cheaper because you don't have to buy a circuit breaker.

[ButchDeal]

Why would a line side tap be more expensive? If anything it is cheaper because you don't have to buy a circuit breaker.

thats funny
there are special taps required that cost money, often a box or trough that costs money, fused disconnect (or breakers), more electrician time...

[Snipely]

This has been a very instructive thread and I appreciate everyone's contribution that helped my understanding. I recently expanded to a 7000W array with an SE5000A-US inverter (no worries on the DC side, as I have multiple azimuths) The specs say this inverter should clip at 5400, and I'm seeing around 5200 W. (Still unsure if this is a real number - is it?) I looked at my last few years of data and I found that I generally peak in April and May at ~4.35 kW, which was with a 5.5 kW system, and on occasion only. Doing the math, the new peak should be about 5.5 kW. I've seen some of the calculations here and fairly confident I am not losing much production overall. Even though my setup is not typical, I hope this adds some useful data to the clipping discussion.

[Ampster]

Thanks for the update. Multiple azimuths illustrate how different ratios work for different situations. Keep us informed as you progress through the soltice.