Optimum panels for EG4 6000xp

[thatlarryguy]

First post but have been lurking for many months. I am building a totally off grid system and succumbed to the Black Friday pressure and ordered 3 of the 6000xp inverters and a full rack of batteries. I will be utilizing a ground mount system but am having a difficult time with panel selection. SS have some 400W bifacials in the $.30/watt price range that are tempting. They show a Voc of 37 and Isc of 13.78. The sales support I chatted with said I could connect 11 of these to each input which would give me 8800 watts per inverter. Although the specs show 8000 watts per inverter all of the kits they offer seem to max out at 6400 watts.

Is the 6400 watts the sweet spot for the inverter or are they just trying to keep the price down? My instinct tells me to lean towards the lower number to preserve the equipment but I don't want to undersize things either. I think the lowest recorded temperature was 10 degrees so that shouldn't be a major factor and the bifacial boost will probably be minimal in this area.

Any advice will be greatly appreciated.

 

[sunshine_eggo]

any panels that form an array that has:

Voc < 480Voc
Isc < 25A (over panel limit, anything over 17A will be wasted)
Vmp > 100V

The above is per MPPT.

Remember, you only get max output at high noon with panels perfectly perpendicular to the sun. You will get less than rated at all other times, and even at high noon, you will almost always get less than rated because panel ratings are STC based, and STC conditions almost never exist.

The recommendation is valid. Being about 10% over-paneled means you'll actually be more likely to hit rated power in optimal conditions.

I don't regard the 6400W as being significant. the unit has over-panel ratings, so it's implied that there's no issue with running the MPPT balls-out.

Using max Imp of 17A and their 320V nominal voltage, that's a 5440W array on a 4000W MPPT.

 

[thatlarryguy]

Thanks for the insights

 

[Steve72]

Are the two MPPTs independent, so that they can take different number of solar panels, e.g. 10 and 8?

 

[redalertdt]

I did the same I went for the hyperion bifacials. I am thinking 2 inverters with 8-9 panels per separate mppt. I think each (2) mppt is separate, so should be able to run different sizes to each mppt input.

 

[sunshine_eggo]

Are the two MPPTs independent, so that they can take different number of solar panels, e.g. 10 and 8?

Yes.