One of critical issue with an AC coupling system is happening when battery has fully discharged.

There is no way to recover back.

 

So, I decide to install an addtional DC coupling

as below

 

Picture1.png

 

 

Two panasonic HIT340 module on the shed at my back yard.

 

2 pannels are connected in series, it can generate 680W. (practically, it can generate 760~780W).

 

back_solar.png

 

 

I have installed cheap MPPT charger,

Actually, this model can support 190V input, and working up to 160V.

When I make 2s 96cell module, Voc is around 130-140V. and Vmppt is around 120V.

It is too hard to use a generic 150V charger.

but, this MPPT controller is perfect in my case.

 

mppt.png

 

 

This is final connection,

 

I have installed 200W 48V to 12V DC2DC for Mini-computer (monitoring), NAS (Data storage & Web Server)

and Wireless Router (to keep on an in-house network).

 

whole system.png

 

I have installed 30kWh battery power

 

The useable capacity is around 24~25kWh. and, It is enough to supply 24 hours full power usage.

or 2-3 days limited power usage at my house.

 

 

 

battery_dc_load.png

 

 

http://www.forby.com/solar/?detail=1&offset=0

 

 

I want to