New 20kw Solar Install - just interconnected - Did we get screwed?

[bcroe]

if OP has full access on monitoring then they can graph production for each inverter independently
as well as DC voltage ( a big indicator of inverter forced clipping when it jumps up).

This significant time in higher voltage clipping for the inverter will likely lead to a shorter life.

Shorter life could be a subject for discussion, it likely varies with the inverter. Have not been
monitoring voltage closely, but these Fronius have been running like this for 6 years on every
sunny day. I try to align panels to limit clipping, but it is happening. Bruce Roe
NScurJn17.jpg

[LCF]

The sizes are also of as the smaller is 7.1kw. They used larger pv modules than initially quoted.
they would have less clipping with the smaller pv modules as you stated but with the larger ones it is much more clipping.
Inverter efficiency should be 98.5%.

if OP has full access on monitoring then they can graph production for each inverter independently as well as DC voltage ( a big indicator of inverter forced clipping when it jumps up).

This significant time in higher voltage clipping for the inverter will likely lead to a shorter life.

Thanks again everyone for all the thoughtful advice, opinions and ideas. Butch I am attaching an image from a graph I made in admin. Its for today only and both inverters. Key is at the bottom.
inverter.jpg

[ButchDeal]

Shorter life could be a subject for discussion, it likely varies with the inverter. Have not been
monitoring voltage closely, but these Fronius have been running like this for 6 years on every
sunny day. I try to align panels to limit clipping, but it is happening. Bruce Roe

The voltage shift would be a SolarEdge situation as that is how the optimizers and inverter deal with clipping.
SolarEdge systems can handle clipping but are not designed for this constant type clipping.
These are not alligned east/west like yours and are shedding a lot of power at these big peaks.
OP would be doing well with an east/west set up and much less clipping but broader production window like yours.

[ButchDeal]

Thanks again everyone for all the thoughtful advice, opinions and ideas. Butch I am attaching an image from a graph I made in admin. Its for today only and both inverters. Key is at the bottom.
inverter.jpg

Yep as I suspected the smaller system is clipping longer from what looks like 10:00 - 10:30 till 3:00 or 4.5 -5 hours of clipping with the larger one 11:00 - 3:00 both with a big DC voltage jump.

[LCF]

Thanks again Butch. So what yoy are saying is that this is not good for the life of the system? Given that, what would you recommend for us to ask them to change for the system to run optimally?

[ButchDeal]

Thanks again Butch. So what yoy are saying is that this is not good for the life of the system? Given that, what would you recommend for us to ask them to change for the system to run optimally?

It depends on your options... did they charge you for the larger size or the smaller size based in the original smaller pv modules?
does your contract specify the inverter models?
Are you actually limited to 15kW for net metering? If so can you go larger of you change the service to 3 phase? And are you willing to do that?

are there any options on the roof to move some of the pv modules west or east?

[J.P.M.]

The sizes are also of as the smaller is 7.1kw. They used larger pv modules than initially quoted.
they would have less clipping with the smaller pv modules as you stated but with the larger ones it is much more clipping.
Inverter efficiency should be 98.5%.

if OP has full access on monitoring then they can graph production for each inverter independently as well as DC voltage ( a big indicator of inverter forced clipping when it jumps up).

This significant time in higher voltage clipping for the inverter will likely lead to a shorter life.

Understood. Thank You.

[neweclipse]

What is hoped to be gained in the end? Just to not clip and not shorten equipment life?

Okay, pretend that happened, what have you gained? What did it cost you? (might not gain near as much as expected but you get it all)


Now here is where it gets interesting...Say you want 3 phase, farm wide, what will you gain and what will it cost you here?


The clipping can be a small, no additional cost and easy fix, but the 3 phase was missed and nobody but YOU will be paying big if that route is now taken.

It's not too late to send that Thank You Card .

[LCF]

It depends on your options... did they charge you for the larger size or the smaller size based in the original smaller pv modules?
does your contract specify the inverter models?
Are you actually limited to 15kW for net metering? If so can you go larger of you change the service to 3 phase? And are you willing to do that?

are there any options on the roof to move some of the pv modules west or east?

Thanks again Butch. The contract does specify the inverters we received but had we been given a choice we would have gone with something appropriate for our long term goals. We are hoping to find out if we are actually limited to 15KW but have not heard anything back yet. 3 phase is an option though we would obviously prefer there be no 15kw cap as it will limit our ability to expand in the future and still remain 100% solar powered. Unfortunately we can't move any of the modules. All our roofs face north/south and they have already been attached to all our metal roofs. I will let you know what I hear when I hear it.

[Ampster]

Thanks again Butch. The contract does specify the inverters we received but had we been given a choice we would have gone with something appropriate for our long term goals. We are hoping to find out if we are actually limited to 15KW but have not heard anything back yet. 3 phase is an option though we would obviously prefer there be no 15kw cap as it will limit our ability to expand in the future and still remain 100% solar powered. Unfortunately we can't move any of the modules. All our roofs face north/south and they have already been attached to all our metal roofs. I will let you know what I hear when I hear it.

I don't know what your expansion plans include but if they involve motors you would definitely want to consider 3 phase because it is more efficient. If I understand the 15kW cap it may only apply to Grid tied generation. How much additional power do you anticipate needing long term? When you say 100% solar powered do you mean on a net basis or are your loads variable such that most of them can be run when the sun is shining?

[neweclipse]

Maybe it's too early do forcast doom and gloom...run this system a while and find the reality...you may gain some new insights.
It's too early to ever say that you'd ever exceed 15kW to the grid...expansion to 30kW production may not have excess enough to ever send 15kW max....the jurys still out on all this.

[ButchDeal]

Maybe it's too early do forcast doom and gloom...run this system a while and find the reality...you may gain some new insights.
It's too early to ever say that you'd ever exceed 15kW to the grid...

OP can SEE clearly that it is clipping at 15kW now. There is no guessing here, it is 100% monitored and easily modeled to see.

expansion to 30kW production may not have excess enough to ever send 15kW max....the jurys still out on all this.

??

did you mean 20kW? if so solarEdge systems have a very flat efficiency curve. The system will produce nearly exactly the same up to the 15kW point and obviously beyond it.
There is no bonus for installing a smaller inverter.

[LCF]

Thanks again Butch. We had a conference call today with the installer. Some things they claimed were that hyper clipping is not damaging to the inverters anymore and that 5+ years ago this was a problem but that it no longer has any negative impact on the inverters. They claimed that the our energy company: National Grid does not have a 15kw cap on single phase, but that National Grid set our cap to 15kw based on our energy consumption (we do not believe this). They also said that in the future the only way we can add on and put more solar in to wipe out any future energy increases would be to do it as a new project, with new inverters and panels and that there is no possibly way to change out the inverters right now as National Grid will not let them. We reached out to our state Office of Energy Resources to try and get a contact at National Grid to try and verify what we are being told.

[neweclipse]

OP can SEE clearly that it is clipping at 15kW now. There is no guessing here, it is 100% monitored and easily modeled to see.

Where I live the sun can be different any day, over time is where the real facts come from, not a day picked here and there.
Clipping is not a fixed steady day to day amount, there can be many days where when there can be zero clipping...then over paneled becomes a welcome feature. One can not have production from capacity that does not exist.

??

did you mean 20kW? if so solarEdge systems have a very flat efficiency curve. The system will produce nearly exactly the same up to the 15kW point and obviously beyond it.
There is no bonus for installing a smaller inverter.

Being the goal here is to be 100% solar wouldn't the grid likely not see much of what is overproduced anyways?
The only kWs that count going out to the grid are the kWs that are not already self consumed on site, or in other words what's leftover.

Why punish the installer just because he installed high wattage output panels than he needed to?
Should he just change to the lower wattage rated panels to make it all as bargained for? Or maybe get paid the difference additional for the larger wattage panels installed?
Or, maybe just call it even?

[ButchDeal]

Where I live the sun can be different any day, over time is where the real facts come from, not a day picked here and there.
Clipping is not a fixed steady day to day amount, there can be many days where when there can be zero clipping...then over paneled becomes a welcome feature. One can not have production from capacity that does not exist.

Why would it be welcome on lower production days? Makes ZERO since.
For most locations a system like this is going to clip most days. It is easily modeled using TMY data and there is no reason to wait with solar so easily modeled on monthly and annual basis.

Being the goal here is to be 100% solar wouldn't the grid likely not see much of what is overproduced anyways?
The only kWs that count going out to the grid are the kWs that are not already self consumed on site, or in other words what's leftover.

OP is looking for a NET 100% offset, not an instant 100% offset.

Why punish the installer just because he installed high wattage output panels than he needed to?
Should he just change to the lower wattage rated panels to make it all as bargained for? Or maybe get paid the difference additional for the larger wattage panels installed?
Or, maybe just call it even?

not sure of the situation around the change here. Were the PV modules installed just cheaper for the installer to get? why was the change made?