* metal hydride to store hydrogen.
* a reversible fuel cell that can either split water to extract the hydrogen, or combine the hydrogen with oxygen from the air to make electricity
* using the "waste" heat as space/water heating (this is another variation of "combined heat and power" and is pretty widely deployed, though perhaps not with fuel cells).
There's been talk about using metal hydrides for hydrogen storage for many decades, and they appear to be commercially available [1]. That said, none of the discussion of hydrogen bulk storage at commercial scale seems to be talking about hydrides - it seems more to be about underground caverns just like natural gas, or tanks if you don't have a handy underground cavern. Hydrogen fuel cell vehicles all seem to be using cryogenic tanks.
If this company has an approach that can lead to anything approximating seasonal storage in a home-friendly form factor at anything approximating a reasonable cost (and that reasonable cost could be pretty high given the functionality), the world will beat a path to their door.