Romania Gets Europe's Largest Air-Powered Energy Storage Plant

Romania is getting Europe's largest compressed air energy storage plant, a breakthrough that could transform how the world stores renewable energy without relying on lithium batteries or rare earth metals.

Two Israeli companies, Airengy and Hagag Europe, are investing $63.6 million to build a facility that stores excess electricity as compressed air in underground salt caverns. When power is needed, the air is released to spin turbines and generate electricity using a simple water-based system.

The technology, called AirBattery, uses only water and air. No toxic materials, no mining for rare metals, and minimal maintenance costs over decades of operation.

The Romanian plant will reach 25 MW of discharge capacity and store up to 5 GWh of energy, enough to power thousands of homes for extended periods. Construction begins in 2027, with the facility expected to operate by early 2028.

Joshua Tzvi, Airengy's VP of Business Development, says the company has already proven the concept works. They started with a small 10 kW pilot in central Israel and now operate a 250 kW plant in southern Israel.

The process is elegantly simple. During charging, excess renewable electricity compresses air and pumps it into underground salt caverns. When energy is needed, the compressed air is released into a hydraulic system where expanding air pushes water through turbines to generate electricity.

Romania proved ideal because it has numerous unused salt caverns, some already connected to the electrical grid with industrial facilities nearby. The country also has a highly decarbonized grid and supportive energy policies.

The Ripple Effect

This project represents a major stepping stone for long-duration energy storage worldwide. While lithium-ion batteries excel at short-term storage, they struggle with storing renewable energy for days or weeks at a time.

Airengy's compressed air technology can fill that gap, helping grids rely more heavily on solar and wind power. The system works in any climate and can operate for decades with minimal environmental impact.

The company is already expanding across Europe, working with partners in Germany and the United Kingdom on similar projects. Each new facility proves that storing clean energy doesn't require expensive batteries or environmentally damaging mining operations.

For Romania, the plant marks a significant entry into advanced energy infrastructure, positioning the country as a leader in next-generation renewable energy storage.

The future of clean energy storage might be as simple as air and water.