Myth No. 1: A grid that increasingly relies on renewable energy is an unreliable grid.
Going by the cliché, “In God we trust; all others bring data,” it’s worth looking at the statistics on grid reliability in countries with high levels of renewables. The indicator most often used to describe grid reliability is the average power outage duration experienced by each customer in a year, a metric known by the tongue-tying name of “System Average Interruption Duration Index” (SAIDI). Based on this metric, Germany — where renewables supply nearly half of the country’s electricity — boasts a grid that is one of the most reliable in Europe and the world. In 2020, SAIDI was just 0.25 hours in Germany. Only Liechtenstein (0.08 hours), and Finland and Switzerland (0.2 hours), did better in Europe, where 2020 electricity generation was 38 percent renewable (ahead of the world’s 29 percent). Countries like France (0.35 hours) and Sweden (0.61 hours) — both far more reliant on nuclear power — did worse, for various reasons.
The United States, where renewable energy and nuclear power each provide roughly 20 percent of electricity, had five times Germany’s outage rate — 1.28 hours in 2020. Since 2006, Germany’s renewable share of electricity generation has nearly quadrupled, while its power outage rate was nearly halved. Similarly, the Texas grid became more stable as its wind capacity sextupled from 2007 to 2020. Today, Texas generates more wind power — about a fifth of its total electricity — than any other state in the U.S.
The act of integrating new control tech and connections into the grid has probably given grid managers opportunity (i.e., budget) to clear up legacy problems that have accumulated over the decades.
As for nuclear power as a source, it does nothing to prevent wind storms from taking down power lines, tree branches from collapsing during ice storms, backhoes cutting buried power lines or yahoos shooting out substations.
Germany has a reliable grid because they kept their coal plants online and they’re building LNG terminals at great expense so their electricity is very expensive. They are also a country with long engineering tradition, which probably has a lot to do with why they kept their coal plants online.
“Germany has a reliable grid because they kept their coal plants online …”
That doesn’t explain why their reliability doubled as RE came online, though.
Here is a good article and graphs on Germany’s energy mix by year:
https://www.cleanenergywire.org/factsheets/germanys-energy-consumption-and-power-mix-charts
Using the same start and end dates of the graph above (2006-2022), all fossil fuel electrical generation declined in total and also individually, even nuclear, while renewables grew in total and individually. So, their reliability went up as coal energy production went down.