I have upgraded system and have the following system
Solar panels 2900 Watts
Inverter Infini Plus
Batteries AGM Batteries 200AH , 48 V system
It took a while to get to this system as there was no clear information available. I have seen lots of views based on personal experiences.
The system is working very fine now. I had MK 5kVA before. The function of Infini is better than MK as being a real hybrid inverter. I do need to mention that we hear a lot from many people of being a true hybrid inverter but I never found clear technical explanation of this word.
A true hybrid inverter means that WAPDA and solar power both are connected to load and the inverter manages use of WAPDA based on the available solar power and the load. The shortage of power is withdrawn from WAPDA if there is any. This means the load is shifted to solar gradually in the morning as the solar power increases and so on in the evening when sun goes down.
For solar panels, anyone should install as more as possible based on the daily power consumption.
1) From my experience, you may get around 10kWh for 2200Watts solar setup. So make sure you have installed enough depending on your daytime power use in kWh. If you don’t know this get it with some help around you otherwise you will waste some of money.
2) You should have solar power less than your peak power use. Usually actual output goes up to 55-60% in summer. Make sure to have balance between your load and the solar power.
Just to mention, MK5kVA was not bad as I used it for two years without any fault. To me, that is a good economical item but you should have one of the following.
1) If you have Infini or any other real hybrid inverter, no need to worry a lot for load management and battery charging.
2) You should have either enough solar base installed to power the load and the battery charging so that inverter does not switches between WAPDA and solar.
3) If you do not have Infini and have any other either normal UPS connected along with a separate solar charge controller or any inverter with built-in charge controller, still the system can work fine by adding some control mechanism to take care of load management.
4) You have to make sure the batteries does not go below 13VDC ( 12V battery) or respective value to your system volt. If batteries go below, you reduce life. Avoid cycling of charge/discharge.
5) Make sure your batter bank is enough to give your load power up to 2 hrs. before going below 12.5V for single battery .
I hope these few words will help understand the requirement.