Interesting read, page-6

Some interesting comments in this thread -

The phrase “grid scale use of lithium batteries...” (ozblue) – weight is less of a consideration as the device is stationary, and so the lightness of Li is less of an advantage compared with mobile phones, laptops and EVs.  It is possible for some other battery type such as Vanadium to take some of the share. Jongo, are Li batteries used in your trials?

“Small jockey wheels on the tracks...” (scrubroad) – physics students know you don’t get energy for nothing. Whatever energy is charging the batteries comes at the expense of the train motion (that is, it will try to slow down the train, so more energy is needed).