Portuguese researchers have found that porous underground rock formations could store renewable energy on a scale sufficient to power entire cities—potentially solving one of the energy transition's biggest challenges.

The breakthrough addresses a critical problem: renewable energy sources like wind and solar are intermittent, and finding ways to store that power efficiently has long been the holy grail of the clean energy revolution. This discovery suggests nature has already built massive storage systems beneath our feet, waiting to be tapped. Read the full story →

Today's takeaway: The solution to renewable energy storage might be as simple as looking underground.