East and West panels combined?

Hi, I’ve already asked something similar, but this is a bit different, adding the extra panels facing East works as planned. But now we added some more apartment buildings to our water system and tying it in to our main solar system is using too much power now, it runs our batteries low and I don’t like the really high amperage it uses. Here’s the question! I’m building a separate system to run the well and pressure pumps. The well pump is 3hp and the pressure pump is 1hp. The well pump runs mostly from 5AM till 11AM, sporadically during the day, then from 4PM till 10PM. The pressure pump runs from about 4:30AM till about 9AM, sporadically during the day, then from about 3PM till about 9PM. We will need our battery power early morning and early evening mostly and I want a backup system to the utility which often produces power under 160v in the morning. Winter sun here usually starts generating power at about 6:15AM and stops at about 6PM. Summer at about 6:45AM till about 7PM. I’m planning on using a Growatt 12kw inverter , 2 batteries with 16, 280ah cells each (48v). I’m thinking of putting 2 sets of 9, 400 watt panels at very steep angles maybe 60 or 70*, facing ESE and 2 sets of 9 400 watt panels facing WSW (14* toward S from E and same for the W, Northern Hemisphere 14.25*N). This might sound nuts but I was thinking of connecting one E set and one W set to each controller in the inverter, connected in parallel through a 6 connection combiner box so the voltage is the same only increasing the number of strings on each, so that as power dropped off from the E set, the power would come up on the W set having it make about the same amount of power all day to charge the batteries, but give a big boost to the AM and PM production. Right now I’m using one of those inverters with 2 sets of 12 400 watt panels and it works great . I know I’ll be buying a lot of extra panels, but I get them direct from the manufacturer for about $100.+ shipping and I’ll already be shipping 24 so it won’t be much more. All of your thoughts and comments will be appreciated. the dog

The east and west facing sound like a good idea to help boost early morning and late evening solar generation, but I would suggest only tilting to 50 degrees so that it operates more effectively throughout the morning and afternoon (otherwise, it might not be able to charge the batteries during the day). Can you start the pumps at sunrise rather than 5 am when it’s still dark?

East and West strings in parallel into one MPPT will work ok. It is quite common to use this configuration, but it only works when the strings are the same length (same number of panels).

Have you considered a Deye SUN-12K hybrid inverter? They have dual MPPTs, so you could have two separate strings. Also, the Deye inverters are better quality than Growatt.

Hi Svarky. Thanks I knew you would have the answer. I’ll do the 50* instead, I was afraid of making too much power during the day. I know to clip a little is OK, but I was afraid it would be too much. The pumps start when the people in the apartments get up to go to work and shut off after the 3rd shift leaves, so I really can’t cut back on them. What I do to limit the amount of battery discharge is I have a second pump, only 2hp, that will be put on a timer and run directly from the utility, set to come on at 6PM and off at 6AM, then the only time I would need more battery power is if the utility power is out. The Growatt also has the 2 MPPTs so I was thinking of 2 combiner boxes for 6 strings each, 9 panels east and 9 panels west for each of them, each running to one of the MPPTs. I’ve been hearing good things about Deye. I was thinking of the Growatt since I already use one of the 12kw with battery back up and a 8kw grid tie and the people who work here don’t really understand the systems and I figured the fewer different types I have the less chance of them damaging something. Plus the manufacturer/distributor in China I have been working with is excellent. They have even helped me with things they didn’t sell me. Thanks the dog.