I assume this is a grid tie system with backup. Frequency shift would only be used when off grid. When on the grid excess would be sold so no need to modulate. Did i miss something?I don't think inverters that use frequency shift to regulate production can do that when connected to the grid.
I think that ratio would eliminate most of the issues raised by @Hedges because the SolArk can curtail its own solar faster when off grid. When on grid I do not recall your system design exceeded the capability of the SolArk. Since you had extensive discussions with SolArk and a vendor I did not pay much attention to those details.Sol-Ark tech support told me it is more efficient to keep the AC coupled panels at about 20% of the total panels
That may be a constraint and one that I recently discovered with my Outback Skybox. My Skybox has has a limit of 5kW export to the grid even though I have almost 9 kW in panels connected. Much of that is derated by several factors. 5.7kW is going through a 3.8 kW AC coupled Solaredge inverter. Another 1.2 is some used panels that are west facing with shade and AC coupled micro inverters. They rarely put out more than 600 Watts. The balance of 2kW in panels are more west facing with some shade connected in series directly connected to the MPPT input of the Skybox. So far I have not seen evidence of any curtailment of solar production since I AC coupled the Solaredge 60 days ago.Looks to me like there is a limit on total PV it can backfeed to the grid, while your 150A main breaker on a 200A or 225A panel allows more.
I haven't looked at those details but at a high level you can always add panels to a grid tie system. Essentially they are AC coupled to the grid.Hedges says I can connect A/C coupled panels to the main electrical panel anyway.
My usage doesn't seem to justify so many panels. And there is the 10K limit for the simplified permit and liability insurance. I have seen people go higher but I think it is simpler to just say below 10K of panels.
Thanks again Hedges. Another reason I decided to go with 10K of panels is because it keeps things simple. I don't want to fail my inspection for something like too many panels or because my panels are too close to the line. And there is a qualifying question on the quick permit application that asks if my system has over 10K capacity.The limit is probably 10 kW AC of inverters.
Normally about 12 kW STC of panels would be used, just reaching 10 kW AC on a typical day with optimum sun angle. Less other season and other times of the day.
You can "over panel", put up more panels so it clips a small amount of the time and produces more during other hours that it would with fewer panels.
I think that with multiple angles, about 18 kW STC of panels can be used on a 10 kW inverter without ever clipping. It gives you 50% more power during a given day. The extra 6 kW STC of panels might cost about $2000 (more or less, depending on model) There are used, UL listed panels available cheap you might add after initial system is complete. Rapid shutdown or optimizers run between $10 and $60 per panel (some models support 4 panels per shutdown box.)
Multiple strings of different angles can be paralleled on a single MPPT input, if all are the same length (similar total Voc & Vmp if different models).
If different length strings, should go to different inputs. Sunny Boy 5 kW and larger have 3 MPPT. A system with 2x SB 5.0 would have 6 MPPT. Have to check detailed specs for minimum voltage and maximum current per MPPT (or for paralleled MPPT.)
Solar Edge has optimizers per panel which allow multiple angles in a single string and up to 24 panels in series.