Hydro power is facing a deepening dry spell

THE world’s biggest source of renewable energy has been going through a dry patch.

Generation from solar farms roughly tripled between 2018 and 2023, while the output of wind turbines almost doubled. That provided enough extra clean energy to power Japan and Russia, put together. Meanwhile, the hydroelectric dams that generate about one-seventh of the world’s electricity stood still: The additional 52 terawatt hours in 2023 was enough to fuel only Greece.

That is not overly surprising. Hydro’s problems resemble those of the other veteran form of clean power – nuclear. Unlike wind and solar, it has been an established technology for decades, so much of its growth potential has already been exploited. Like nuclear, it is dependent on the building of costly and time-consuming projects to move forward, and shows little sign of reducing its (already low) costs.