Am I doing this correctly? (Growatt / 1P16S 304AH / 1P9S 455WP panels)

[drbytes]

Hi

Before I get deeper into this solar adventure I would like to hear if I'm doing it correctly.

European setup, 230v grid, mono phase, max load on the house 4500watts. It can happen however that the wifu goes apesh*t and turns everything on and I've seen occasional loads of 7000 watts (this happens when the baby soils the bed and therefore the washer, dryer and sterilzation equipement is turned on at the same time -- that does not happen frequently, but it can happen)

Here's what I have; 9 panels, the panels were free for me and they are brand new. They are Longi Solar 455wp, product number: LR4-72HPH-455M.


These are already installed, I've set them on the ground under a 36degree angle facing south. They are about 40 meters (single run) in cable removed from where the inverter will be installed. Cable is 4mm2. I measure 430volts or thereabouts on a sunny day OC.

Because of reasons I'm looking to get an off grid inverter, I do not want to send anything back into the grid, if I do send power to the grid the government has all kinds of annoying paperwork and regulations that i do not want to deal with. THey'll want to change my meter, I'll have to re-certify the whole electrical installation, just because.

The Growatt spf5000es looks really good. It would be able to cover the normal load, but the apesh*t load of 7000 watts would .. would what? I dunno, does it cut back to the grid at that point or does it just cut out completly? IF it cuts out completly I would need to get a second one.

With the panels all in series connected to the Growatt, I should be fine, right?
It does freeze in this country, does that mean I could get into trouble with the voltage?
What are my options then? Maybe I get another panel and do 2p5s? The datasheet on the Growatt does not mention the max amperage input ( datasheet: https://www.estg.eu/nl-nl/amfile/file/download/file/4296/product/3618/ ). I read on this forum that it's 18A and newer models do 22A. I think I would be delivered a newer unit and therefore with 10.92A (x2) STC rating I should be fine.

Now for batteries, I've ordered 16 EVE cells, 304AH from Amy, that should give me 15,5kwh and get me trough the nights on battery without depleting them completely each night. Night load is 1kwh.

Ok .. so what's wrong with this setup?

cheers

 

[MisterSandals]

With the panels all in series connected to the Growatt, I should be fine, right?

Isn’t the max input voltage 250V or something like that?

I would look at 3S3P array which would produce about 150V and about 30A.
The wiring and fusing for 40 meters will be more than standard solar wire.

Maybe I get another panel and do 2p5s?

5S2P requires a single Y connector and is easy to connector. The question is whether your SCC can handle 5x Voc plus 15-20% for cold temp based voltage increases. If max input is 250V, then no.

What is MPPT (optimised function) voltage range for SCC?

 

[drbytes]

The Growatt can take 450v OC, MPPT range 120VDC ~ 430VDC

 

[MisterSandals]

The Growatt can take 450v OC, MPPT range 120VDC ~ 430VDC

5S2P is a great solution.
If you have the ability to point one 5S string east-ish, and one west-ish, you can extend your charging hours and charge at a lower amperage rate.

I know nothing of Growatt, try a search and read what folks have to say.

Now for batteries, I've ordered 16 EVE cells, 304AH from Amy, that should give me 15,5kwh and get me trough the nights on battery without depleting them completely each night. Night load is 1kwh.

That’s a nice battery.

Have you done an energy audit to see how many watt hours you use each 24h period? That will tell you more than any other step in this process.

There are a couple energy audit tools in my signature.

 

[drbytes]

30kwh max.
This setup is a test to see how much I can lower the draw on the grid

 

[drbytes]

So I have an update, the Growatt will start to beep at 5500watt draw but it continues to work. THe voltage output does drop then. SO I'm adding another inverter to the setup. Which will give me another mptt solar input for east facing panels so that's actually fantastic.
So far the system, without a battery, has cut 25% off my typical day consumption even with overcast skies and being December.

 

[chacha]

Hello, If I can resurrect an old thread. I'm very new to all this, my solar knowledge is 2weeks old.

I am looking at getting a Growatt SPF 5000ES, 450v Open Circuit, MPPT range 120VDC ~ 430VDC

I got hold of 10 Jinko 280 watt panels around 4year old.

Vmp 31.8V
Imp 8.81A
Voc 38.6V
Isc 9.49A

Im thinking of either a 5s2p solar arrangement that will give me approx 200Volts 20Amps or is it better to have the 10 panels in series with 386V and around 10Amps. Full sunlight no shade site.

The run to mppt will be some 20 meters, voltage drop is very little. My concern with the 10 panels in series is that with variables in weather or other things the voltage may rise a bit, though it rarely gets to 0c.

I would prefer the 5s2p but is 200V being around half the total Voc of 450 and only 80Vdc above Min range of mppt a concern, or is it more a concern having 10 panels in series which at 386Voc may be too close to total Growatt Voc of 450.

Hope I made some sense.

Thanks

P.s What's the diff of a 5s2p or a 2p5s

 

[MisterSandals]

P.s What's the diff of a 5s2p or a 2p5s

5S2P is 2 separate 5S strings connected in parallel. This requires a single Y connector.

2P5S aid 5 pairs in parallel, all 5 pairs then connected in series. This requires 5 Y connectors.

 

[dianea]

I have a Growatt SPF5000ES and my electric dryer runs at 5300 watts at 240V,...but if I select 220V output from the Growatt, the dryer only consumes 4800 watts.

 

[chacha]

5S2P is 2 separate 5S strings connected in parallel. This requires a single Y connector.

2P5S aid 5 pairs in parallel, all 5 pairs then connected in series. This requires 5 Y connectors.

Thanks , seems the amps would be way to high with 2p5s

 

[chacha]

I have a Growatt SPF5000ES and my electric dryer runs at 5300 watts at 240V,...but if I select 220V output from the Growatt, the dryer only consumes 4800 watts.

nice

 

[MisterSandals]

Thanks , seems the amps would be way to high with 2p5s

Your array amps would be the same with 2P5S as with 5S2P (18.98A Isc).

 

[chacha]

Yeah well, that's how much I know ). So why choose one over the other.

 

[MisterSandals]

So why choose one over the other.

2P5S aid 5 pairs in parallel, all 5 pairs then connected in series. This requires 5 Y connectors.

4 fewer Y connector pairs.
5S first makes it super easy and less likely to have cable length reach issues between the 5 2P pairs.

If you have shading issues, having a lot of 2P pairs, if one panel is shaded it could affect the 2P pair (lower combined amps) and bring down the other 4 pairs in series by limiting all the pair amps to the lowest.
With 5S first, a shaded panel would bring down this string but not the other 5S string connected in parallel.

Without shading issues, what is downstream from your array will not know the difference between the 2 configs.

 

[chacha]

Yeah ok, I had read something re that , when I get round to it I 'll take the easier 5s path. Big Thankyou MisterSandals