Here is a nice basic introduction to the existing technology options for deploying large-scale grid connected energy storage solutions.
What is very interesting is that while all of the 6 big technologies are introduced, only one is referred to by a brand name.
Lithium based energy storage is a HUGE industry, led (by sales volume) by monster MNCs like Samsung SDI, LG Chem, Panasonic and BYD.
But in this article, the technology is referred to as "TESLA POWERWALL".
It seems Tesla's marketing department has effectively brainwashed people into thinking TESLA owns Lithium battery technology.
This despite the fact that Tesla is essentially just a distributor of Panasonic batteries.
Panasonic supplies to Tesla the IP, manufacturing process and controls the manufacturing of the lithium cells manufactured in the Gigafactory. Tesla is only the land owner and sales function of the products that are manufactured there.