For your 10kw something less than 3 kws would do. In fact I suspect Ryland was pretty close with 2.1kw.
My not terribly relevant baseline is derived from generating 4 kw avg. daily with an offgrid 1kw system. At 12v the system overcurrents at around 850 watts but in lower light conditions the larger array creates more power (cloud, haze, morning, full moon
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Being offgrid my system throws away power after the batteries are full. I tested a 13.5 amp a/c for kicks and generated 5-6kw daily.
With an ongrid application you should do much better.
I have a friend building an ongrid 3kw system. What inverters have you been impressed by?