Ann: Redflow & Empower Energies announce strategic partnership, page-22

It's mostly to do with long term energy storage.

With most battery chemistries, you charge up the battery, and then you have a "use it or lose it" situation: the battery leaks charge over time. How much leakage, and how that impacts the energy available when you need it, depends on a combination of time and the battery chemistry; even within a broad category of chemistries (eg: nickel metal hydride), the ability of a cell to hold a charge can vary dramatically. (When talking NiMH, I will only ever buy Eneloop for exactly that reason - they're the only one that has proven to be reasonably reliable in holding a charge for a long-ish period of time. Energiser? No flaming way; those cells were useless after a few charge/discharge cycles. [I used to do a fair amount of photography with a flash; you want rechargeable batteries, not alkaline, for camera flashes - the internal resistance is much lower, allowing them to deliver a much higher current when the flash cycles. Hence the knowledge.])

With a Redflow battery, you can put it in hibernation, and you'll have the energy there, ready to go, when the battery comes out of hibernation. Perfect for environments that need energy stored for, eg, supply disruptions, but don't need it all on tap all the time. If you have three modules, you can have two of them cycling and the third in hibernation, only to bring the hibernating battery out if there's a disruption and it looks like you're likely to need the energy.

It's basically Redflow saying, "You don't need to worry about energy leakage if you put the battery into hibernation - you'll have the full 10 kWh available to you when you need it." There's a period of time to bring the battery out of hibernation, so you wouldn't do it with only one cell, and you wouldn't do it with all your cells - but there are legitimate use cases for it (substituting for a generator, for example.)