Consider the distance, and speed of light, and the speed of electricity (1/100th of that). I don't think it's truly feasible to keep that much physical space in sync. Hmm...
I've also heard, but I can't explain so you'll have to look it up yourself, that none of this matters when keeping a grid in sync anyway. It just works out.
https://en.m.wikipedia.org/wiki/Synchronous_grid_of_Continen...
This might counter the grandparent poster if Asia was on the same synchronous grid, but it's not.
Here's the map including all larger powerlines
It spans 8 timezones.
Europe is just larger in capacity, not breadth.