I’d love a shed sized battery sitting on the corner of my property if it could give me 5-7 days of power.
I have 15kwh of lifepo, and even if it weren't hooked to 4kw of solar I could still run my fridge, charge my phone, and run the fan in my fireplace for 4-6 days... longer if I dump the fridge.
It's 6U of deep 19" rack space.
So 2 x that isn't an entire shed-sized battery.
Though I'd happily have a shed-sized battery... I suspect that delivering and covering something that size would cost more than the batteries I already have, though.
If the GP commenter is typing in from the UK .. that's a not uncommon garden tool shed size.
By contrast modern Australian farm sheds have clouds forming within them and host birds that seasonally migrate from one side to the other.
I've never had to turn off my fridge, though it does have interesting-to-me usage patterns; it's weird what you can learn once everything you use has a watt-meter. I can look at the weekly graph and recall when I turned on a hammond organ or cooked in my instapot.
Re use old ev batteries unmodified for battery storage
The other potential problem with a lot of energy systems that use things that have hydrogen in them is running power over the systems for long periods of time can start to leak hydrogen. You'll always want to ensure you have ventilation to ensure whatever is outgassing can escape the system. You'll end up with explosions, hydrogen embrittlement, or interesting corrosion in ways you didn't think were possible.
If this battery plus some solar panels could get us free power for the next 20+ years, that's easily worth $15-$20k or so.
I live in middle of nowhere so I just built out a system myself. I am about 8k into it. It's not the biggest system (6kw inverter, 4kw panels, 15kwh storage) but it's fine for one old man living a 2kM in the high desert.
I live in a very rural spot with a difficult-to-deal-with Electric Association, with a Ute reservation on one side and unpowered parcels on other sides; I don't think that the easement is a typical issue.
And to be clear, I didn't count my labor in designing or implementing the system. I suspect that would have been somewhere in the neighborhood of another $10K if I had to get a hands-off, turn-key version of this same system.
And at some point I will likely double much of the capacity, at which point I will be able to run a mig welder at night if I want...