Adding more solar to my existing off grid setup

[HughF]

I'm considering my options for adding an additional ground based array to my current off grid solar setup.

This extra power would be to help run AC side loads in the summer time (EV charging, domestic appliances etc) that have a higher demand than our current 2.4kW array can produce.

I currently use exclusively outback power systems products, with their 60a MPPT charge controller chargin my 9.6kWh LiFePo4 pack.

My question: would I be insane to consider adding this solar to the AC side of things, using a regular grid tie inverter (SMA Sunny Boy or similar)? This would make the wiring a lot easier as I can couple that into the property on the AC side easier than routing it back to the power building.

Or should I just buy another outback MPPT charger and add it on the DC side?

Thoughts....

[Hillhater]

How much power do you anticipate using ?
.....your existing 2.4kW system cannot be producing much more than 8-10 kWh ?
What capacity of panels are you thinking of adding ?
Do you want/need to go grid tied ?

[JackFlorey]

My question: would I be insane to consider adding this solar to the AC side of things, using a regular grid tie inverter (SMA Sunny Boy or similar)? This would make the wiring a lot easier as I can couple that into the property on the AC side easier than routing it back to the power building.

Yes. You can add a limited amount of AC coupled power to most hybrid inverters. Choose inverters that use frequency shift to shut down AC generation, and then use a relay as a safety. The Sol-Ark will do both without modification. I think you need to add a relay with the SMA.

Here's the Sol-Ark recommendations for AC plus DC coupling:

• Best: 3kWAC + 11kWDC (8KW sell)
• Good: 2kWAC + 12kWDC (9KW sell)
• OK: 4kWAC + 7kWDC
• Poor: 5kWAC + 6kWDC
• Poor: 6kWAC + 5kWDC

[HughF]

How much power do you anticipate using ?
.....your existing 2.4kW system cannot be producing much more than 8-10 kWh ?
What capacity of panels are you thinking of adding ?
Do you want/need to go grid tied ?

We are completely off grid, no grid available in our area. My existing system can generate about 8kWh/day, maximum, in the summer. But only if we can use it. In the summer we are in float at 11am sometimes so without running the washing machine/dishwasher etc, we can't use all that sunshine. Yes, I'm looking to add another 10kWh of LiFePo4.

I'd like to add another 2-3kW of panels so I can charge my car off another 3kW inverter I have, when I'm at home and the sun is out.

[Hillhater]

Most solar users “reschedule” their usage, ..washing , drying, water heating, cooking, etc etc, ..to occurr during peak solar periods ..i assume you are doing that ?
But still. 8 kWh at best is a hard to meet, low usage level....so yes an upgrade to both panels and storage would seem logical for a comfortable life.
Battery storage is available cheaply,,$200_$300 /kWh so not too scary !
https://signaturesolar.com/shop-all/bat ... ifepower4/