The cost of transmission is partly a factor of peak usage.
Like if you build a highway and everyone commutes at exactly 9-5 then that dictates how many lanes you need.
In places with air-con, the distributed solar reduces the peak on a daily and yearly basis.
Distributed batteries also help with this.
In grid lingo these are called "non-wires alternatives" or "non-transmission alternatives"
https://en.m.wikipedia.org/wiki/Non-wires_alternatives
