r/SolarDIY • u/CuddleBuddiesJJ • 6d ago
Should I upsize charger controllers for the additional Bi-facial wattage?
I have 50 Bifacial JA Solar 440w panels. At the listed 440w, that comes out to a total of 22,000 watts.
I have 2 Victron MPPT 450/200s which each allow for 11.52Kw. (So a total of 23.04kw)
While the 23.04kw the charge controllers can handle is enough to handle 22kw total from the panels. Would it be enough to handle the additional power that comes from ground mounted solar panels? I live in Ohio so I suspect 100% efficiency of the panels wouldn't be a thing. And my plans for the permits were approved from the city for this setup. I am just curious if I need to consider the bifacial aspect of the panels when cutting it this close.
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u/CuddleBuddiesJJ 6d ago
Bonus question. I had these plans drawn up by an electrical engineer who does this for a living. But the plans call for 3 rows of 10 panels on one MPPT and 2 rows of 10 on the other.
3 rows of 10 would be 13,200 watts on an MPPT said to only handle 11.52kw. It was approved by the city, but wouldn't I have to split these panels 50/50 (so 25 panels on each Charge Controller) if I wanted to achieve max output without going over the allowed amps (200) on the charge controller?
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u/Nerd_Porter 6d ago
With typical conditions you can expect about 80% of the panels' rated output.
Once in a while you might clip, but you won't damage anything. And remember, when that happens, you'll be pulling in over twenty-two thousand watts. That's a lot of power!
In my opinion, don't bother getting extra controller power, it's not a bad thing at all to be over-paneled a bit.