Comment by ttul
5 hours ago
Fortunately, interconnects cannot go out of phase easily. If one region is out of phase with another, massive currents flow down the transmission lines within milliseconds, causing generators at one side or the other to slow down or speed up. I have seen this effect live at a hydroelectric dam. We were watching the turbine shaft spin at the moment they switched on some giant interconnect. There was a phase-alignment dial and it just instantly pinged up to 0 while the spinning shaft shuddered, slightly altering its rate of rotation in the blink of an eye.
Is that same functionality available in solar or wind type scenarios?
When I heard the Spain issue being described by a grid engineer, they were focusing on the lack of rotational mass in those systems compared to the large turbines used in other generator designs as the reason solar could go out of phase more easily. What you're describing sounds like that scenario, hydro has large enough rotational mass to keep things stable.