I'm told there are three separate power grids in Usania: East, West, and Texas. So when the Texan voles aren't running, the voles from elsewhere can't be tempted to take their place.
I expect it's not quite as simple as that but.
It's not. There's Canadians involved in the big ones. And Alaska has two grids of its own (I suspect
BEARS make interconnection problematic or something).
But for these porpoises, it's sufficient to know that:
a) Like the UK and Europe, these grids aren't synchronised with each other. So you can't just wire them together to borrow some electrons. Like us, there'e some limited import/export capability via HVDC connections.
b) Texas has its own grid for ideological "sticking it to The Man" reasons.
c) Just like the Californians, they did capitalism, and failed to engineer their power systems in a way that could cope with rare, but entirely foreseeable, extreme weather.
d) Texas has a surprisingly large amount of wind power, much of which isn't working because (c), but this is a small portion of their total capacity, and the bulk of the problem is the natural gas infrastructure that isn't working because (c).
e) This is however a prime target for ideologically-motivated claims about the inadequacy of wind power, which can readily be disproved by observing the countless fully armed and operational wind turbines operated in ludicrous weather by extremely competent Scandiwegians, and indeed the more pragmatic Leftpondians from higher latitudes.