448880W, about 1/2 megawatt, is quite a large load, 20 times larger than large home systems individuals might install.
I assume you mean this is the continuous power, so you would consume 12 megawatt hours each day.
When you say, "65% of the stored electricity needs to be provided to the system" I am not sure what you mean.
Does 35% of electricity come from elsewhere, like utility grid?
Or is 35% from solar panels during the day and 65% has to be stored in batteries for night time use?
There are some vendors lf large industrial systems.
From SMA, here is a 2.2 megawatt battery inverter:
Preconfigured, well-matched system components as complete solutions.
www.sma.de
A 75 kW inverter. I think multiple units possibly can work together to make a larger system.
Information on the Sunny Tripower Storage 60 (no longer sold by SMA) ► discover the successor here!
www.sma.de
Separate photovoltaic inverters can be integrated in the system.
You should contact and get their recommendation of a system.
If your system is much smaller, please give us corrected numbers and we can be of more help.