The Physics Behind the Spanish Blackout

Bjorn Lomberg writes:

When a grid failure plunged 55 million people in Spain and Portugal into darkness at the end of April, it should have been a wake-up call on green energy. Climate activists promised that solar and wind power were the future of cheap, dependable electricity. The massive half-day blackout shows otherwise. The nature of solar and wind generation makes grids that rely on them more prone to collapse—an issue that’s particularly expensive to ameliorate. …

Grids need to stay on a very stable frequency—generally 50 Hertz in Europe—or else you get blackouts. Fossil-fuel, hydro and nuclear generation all solve this problem naturally because they generate energy by powering massive spinning turbines. The inertia of these heavy rotating masses resists changes in speed and hence frequency, so that when sudden demand swings would otherwise drop or hike grid frequency, the turbines work as immense buffers. But wind and solar don’t power such heavy turbines to generate energy. …

Just a week prior to the blackout, Spain bragged that for the first time, renewables delivered 100% of its electricity, though only for a period of minutes around 11:15 a.m. When it collapsed, the Iberian grid was powered by 74% renewable energy, with 55% coming from solar. It went down under the bright noon sun. When the Iberian grid frequency started faltering on April 28, the grid’s high proportion of solar and wind generation couldn’t stabilize it. This isn’t speculation; it’s physics. As the electricity supply across Spain collapsed, Portugal was pulled along, because the two countries are tightly interconnected through the Iberian electricity network.

It makes a lot of sense to have a high proportion of your energy from renewable sources, especially hydro. But trying to be 100% dependent on renewables (as Ardern pledged) defies physics.