Yeah it's a bit confusing. When I hear "battery capacity" I think about GWh not GW but I suppose it isn't "wrong" as it can mean output "capacity" and they did mention "in GW"

Not sure where you're getting the numbers from but I think @DarthFrodo@lemmy.world is right here as in the differences in numbers are probably explained by the fact that the first number is only for batteries used to balance the grid and the other one is more general.

But yeah you do make a good point that we have no clue about actual storage capacity. Still, really strange that EU numbers are so low. I expected way more.