This piece originally appeared at Nuclear Barbarians.
In April, blackouts darkened Spain. Trains stopped, traffic lights blinked off, planes idled on runways. The Spanish government declared a national emergency.
I covered these events in a piece for Compact, which was then reprinted under a different title in The Free Press.
And my diagnosis was wrong — or, half-wrong.
This was my (as I admitted at the time) educated guess about what caused the blackouts:
Simply put, the power grid is like a giant game of tug of war. On one side, there’s demand, and on the other there’s supply. Keeping the lights on involves making sure the rope between supply and demand remains taut. This tautness is called inertia.
Healthy inertia means healthy grid frequency, which in Europe means 50 Hertz (in the United States it’s 60 Hertz). The Portuguese grid operator claims that something along one of its power lines disrupted the even flow of power between generators on its grid, which messed with the frequency, which likely tripped off more wind and solar, which slackened the rope, which probably caused the blackouts.
I guessed that a lack of firm, dispatchable resources on Spain’s grid had created inertial precarity. As Bloomberg’s Javier Blas reported at the time, thermal generation in Spain was at a troubling low just before the blackouts.
