Best PV Array Settings?

[MikeSolarPT]

Hi, i wondering what is the best config for my PV array, especially during winter.

I have 10 445W solar panels, that combined give me 4500W with 10amps and 450volts on a series array. This is at max of the operating range VOC on the inverter.

Should i switch to 2 series one parallel string with 5 panels each at 245VOC and 20amps on the inverter? this will be better for the winter conditions for the mppt?

With only one series, i noticed that the mppt starts at 145volts until it jumps to 400volts working voltage with a great increase in power.

 

[snoobler]

If your 10S Voc is near 450V and your MPPT Voc limit is 450, good chance you may kill the MPPT when winter comes.

5S2P would be a better choice. I think that's what you described.

 

[MikeSolarPT]

If your 10S Voc is near 450V and your MPPT Voc limit is 450, good chance you may kill the MPPT when winter comes.

5S2P would be a better choice. I think that's what you described.

The recomended operating range is from 120volts to 450volts . The max is 500VOC.

My problem may be that the max amp of the mppt is 20 amps and 5P2S will be 23amps in open circuit and 21 amps operating. This can kill my mppt charger? ou it will just limit the current to 20amps?

 

[snoobler]

If it doesn't get much below freezing, then 450Voc vs. 500V max PV input is fine and no changes are needed.

The MPPT would just ignore the excess current, and you'd lose ~5% of your array power.

 

[houseofancients]

If your 10S Voc is near 450V and your MPPT Voc limit is 450, good chance you may kill the MPPT when winter comes.

5S2P would be a better choice. I think that's what you described.

im guessing you run a mpp solar/voltronic/clone unit.

2p would surpass the 20 amps, thus frie the mppt.
better off running them in 1 string.
you probably have a second mppt, use that if you need more strings.

2p strings is possible, but the amps shouldnt surpass 9 amp ( in other words, 250 - 275 watt panels

 

[snoobler]

im guessing you run a mpp solar/voltronic/clone unit.

2p would surpass the 20 amps, thus frie the mppt.

That's just not true. The MPPT is a load and like any load, it determines how many amps it needs. It will never pull more than 20A even if more are available.

Exceeding the current rating on a PWM SCC is a big no-no as they can't regulate incoming current.

 

[MikeSolarPT]

If it doesn't get much below freezing, then 450Voc vs. 500V max PV input is fine and no changes are needed.

The MPPT would just ignore the excess current, and you'd lose ~5% of your array power.

Yes i will be loosing some power but in winter i will never get full optimal PV conditions, so i will get max available power. In the summer the 4500W are more than i can store and use during the day. At this time i use 12kw a day, and the PV produces 30kw daily. I have the batterie always full at mid day.

I just want to optimize the winter time, when i get less sun hours and more couldy conditions.

 

[snoobler]

Yes i will be loosing some power but in winter i will never get full optimal PV conditions, so i will get max available power. In the summer the 4500W are more than i can store and use during the day. At this time i use 12kw a day, and the PV produces 30kw daily. I have the batterie always full at mid day.

I just want to optimize the winter time, when i get less sun hours and more couldy conditions.

In that regard, 5S2P vs 10S doesn't matter at all. I missed the "winter" detail in your original post.

Panel orientation and tilt are the only ways you can meaningfully optimize for winter PV production.

Unless you're at an extreme northern latitude with very inclement weather, an array capable of producing 30kWh during the summer has a good chance of producing 12kWh during winter. However, unless you have 3-4 days of battery capacity, you will almost certainly need to run a generator from time to time. Even here in AZ, while the "average" day is awesome and only about 10-20% worse than fall/spring (year round panel tilt), winter weather may have 2-3 consecutive poor solar days, and a generator is required.

 

[houseofancients]

a direct quote from the manual .

" never exceed the amp limits as it will permanently damage the mppt"

 

[snoobler]

What manual?