Growatt 5000es 48v - Auto Transformer - 410W Bi Facial Panels

[David Self]

Hello everyone,

This is going to be my first build, so please go easy on me. I am a software engineer, so I'm pretty decent at most things mathematical.

As you can see in the subject, I am planning on building with the following components.

• Growatt 5000 es 48v 240vac Inverter
• 5kW Midpoint Auto transformer
• 410w Split Cell Solar panels (10x pack)
• Battleborn 50ah 24v Batteries (2x for 48v)

My question is regarding the inverters max VOC (voltage open circuit.) The manual says the inverter can handle up to 450VOC. The panels state on the website specs that they have 49.0 front and 49.50 back VOC. I want to get as close to the 5000 max watt input as I can, so normally I would just put the panels in series until I get a little under the max VOC right? Problem is, they are bi-facial, so do I need to leave more room for those kind of depending on the day (sunlight)?

Also, the site only offers a 10 pack of the panels, so would it even be possible to series/parallel 10 of these panels to stay within the thresh hold of the Growatt 5000 inverter?

I have purchased the inverter and transformer, so if you recommend specific panels/batteries I'm open to your suggestions. I plan to run a refrigerator/freezer and a 240 mini-split heat/ac pump. Potentially some small 12v appliances in the future.

Thank you in advance, and I'm a huge fan of Will Prowse. I've seen pretty much all his videos

 

[Turricon]

I'm in KY I just purchased this set up as well but 24 250w used santans for 6kw. the guys at signature solar told me at 37.6 voc i could do 12s 2p set up. Puts it at 451v +- a hair, 18.? amps, knowing i could never get full voc where I live. Even in winter with the panels cooler ( suns not at the right angel then ) and due to the fact they are used panels.
I question this somewhat but can see it from both sides. Somewhere on the site here i saw a math formula with voc times panels voc in series and i think * 1.2 for top voc ( accounting for winter cold panel output) . Hope that help ya some, I myself am learning as well.

ohh also noticed this unit is max 6kw input 5kw output by the way.

 

[wtrey613]

What climate are you in? can you tell me more about the environment you plan to mount these? we just ordered the Growwatt and the inverter.
Also i use this calculator to calc my VOC. I would call signature solar and ask them.

PV Array Calculator for the Magnum Energy PT-100 Charge Controller | Magnum Dimensions

Accurately calculate the number of PT-100 Charge Controllers you need based on your PV array.

www.magnum-dimensions.com

 

[wtrey613]

also i would watch these videos as well david poz

 

[newbostonconst]

Here is a nice series parallel calculator....

MPPT Calculator - Victron Energy

MPPT Calculator - Victron Energy

www.victronenergy.com

 

[Turricon]

I've watched all his vids . Mid climate 70-90 summer 15-32 winters. Mild.

 

[Jim Lee]

I'm not an electrician. It is my understanding that SPF5000 ES has a 450 VOC definite maximum and 18 amp cut off. Above 18Amps would just be clipped and no harm to the inverter, but go over 450 volts and your inverter dies. At 49.5 VOC per panel your maximum series would be 9 panels, however, for safety and figuring the possible -10 degree sunny day that might only happen once 7 or possibly 8 panels would be your maximum series which would allow for cold weather voltage spikes.