The Physics Behind the Spanish Blackout

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.