Why not expand the power lines across the map, make em connect to new substation POIs, right?
Then have a special machine that cannot be picked up in a power plant around LV (Maybe the MC Alpine Dam? Trimble County Power Station? Both are IRL places...) which would take gas/some sort of fuel (or maybe just repairs?) like a normal generator, and sends some sort of data to the substations, using the power lines. BUT, if the power lines get destroyed, the substation(s) relying on that connection shut off.
The substations also add load to the grid when turned on.
The power machinery cannot be refueled by default (sandbox option), to emulate the old system of a days system. So like, it's only got X days of fuel.
A powered substation will generate power for the cell it's in, plus an X-by-X square around it.
Maybe have a sandbox option for certain occupations being the only ones able to fix this new grid machinery? (only Electricians can toggle substations, toggle the main power plant(s), fix power lines?)
Lastly, the grid would have load. So each substation adds X load to the grid, and every X days the power plant's operational would add load, to simulate wear and tear. Here's where engineers could shine, being able to fix the power plant machinery to reduce the days counter? If the grid load exceeds the grid capacity, the machinery shuts down at the power plant, requiring the grid load to be reduced to a manageable state before an electrician could turn the machines back on?
like theoretically, with the glowups in progress, this shouldn't take more than a few weeks to implement a basic version of.
like, the introduction of power plants (and possibly the water treatment plant in JeffersonCounty, S/E LV) would give users a real reason to go to LV. Especially after the awe of the glowup wears off.