How Many Solar Panels 48V

[andypop1]

I'm looking for a starting number of panels & size.
Goal for now to run a 4 kWh home AC during the Day, 12hr od use).
(AC 4 ton system, 240v 30A)

Current Equipment:
Growatt 12kW 48V 150VDC 120A Off-Grid Inverter
200 aHr 48v Li batteries

I'm thinking 2 series of 4 365w mono's

Advice would be appreciated not sure at this point.

TIA
AndyPop

 

[Samsonite801]

You'd have to post the exact specs or picture of a sticker on a particular solar panel to make accurate Voc calculation in order for anyone to confirm what would be acceptable for use on your Growatt.

Typically though, 2 average panels in series might be around 100v Voc (maybe a little less or something), check your Growatt, if it is max PV Input spec is 150v then it should be fine, but just double check it...

In other words, when looking at various panels, focus in more on looking at the specs so you can calculate Voc on the PV circuit and make sure don't go over what the MPPT PV input can handle on the AIO or charge controller. You also have to add in some wiggle room for cold temperature offset on Voc.

On watts, I always would just go with max I can find at best price, so 405w for me, it winds up cheaper in freight, because a pallet of 200w costs the same to ship as a pallet of 405w for example.

 

[MichaelK]

A good rule of thumb for powering equipment is to double the number of watts of panels for the load you are trying to run. So, if you want to power something that needs 4000W, you need at least 8000W of solar.

BTW, that most likely will work only with rotating arrays that you can track east to west over the course of the day. Even 8000W of panels is not going to run that load at 8am if they are all facing south.