This is essentially a UPS (uninterruptible power supply) with an app. The UPS basically passes power from the wall to your fridge until there's a power outage. At that point it flips to using the battery to send power to your fridge.
My one question would be: does it work with home assistant? It would be great to integrate in te energy dashboard.
As an important caveat on solar: if I'm reading correctly, it appears that the main unit only has support for a small amount of solar input directly connected to it (100 W, which makes me suspect it may be using USB PD for input), while larger amounts need the expansion pack, or a separately installed system.