I could see this being the case for regional balancing, but presumably a 1GW generation site has a 1GW-capable link to the grid, otherwise that seems like overb

I could see this being the case for regional balancing, but presumably a 1GW generation site has a 1GW-capable link to the grid, otherwise that seems like overbuilt capacity? (nb of course you might overprovision it to some degree on the presumption that, say, only 70% of your generation is usable at any one time; I more mean the numbers like say 16%.)