Energy Dome began operating its 20-megawatt, long-duration energy-storage facility in July 2025 in Ottana, Sardinia. In 2026, replicas of the system will begin popping up on multiple continents. This giant bubble on the island of Sardinia holds 2,000 tonnes of carbon dioxide. But the gas wasn’t captured from factory emissions, nor was it pulled from the air. It came from a gas supplier, and it lives permanently inside the dome’s system to serve an eco-friendly purpose: to store large amounts of ...