Battery backups and diesel generators at the interchange, both of which are only temporary. Batteries need to be charged and diesel needs to be pumped, and while you can (and most infrastructure resiliency relies on it) operate these systems on manual power, the stability of large infrastructure systems becomes quite vulnerable once it’s necessary to run a diesel generator to pump diesel for your other diesel generators.

They absolutely do not. They just don’t require power locally, but there’s 48v on the line that needs to be generated somewhere.