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. It’s possible to make up for this with cutting-edge
technology such as advanced inverters or synthetic inertia. But many
solar and wind farms haven’t undergone these expensive upgrades. If a
grid dominated by those two power sources gets off frequency, a blackout
is more likely than in a system that relies on other energy sources. ...
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. ...