Southern Europe Air Energy Storage Project

Compressed Air Energy Storage (CAES) offers potential, but faces challenges including poor efficiency and reliance on fossil fuels. In this context, the EU-funded Air4NRG project aims to improve long-term energy storage. Specifically, it targets over 70 % round-trip efficiency, sustainability, and integration with the grid.

Air4NRG aims to revolutionise energy storage by leveraging isothermal compression-expansion technology. The project will provide robust, safe, and scalable energy storage solutions, using local materials to promote European industrial leadership and reduce dependency on imported resources.

Compressed Air Energy Storage (CAES) has been a valid possible solution for decades. However, its poor energy efficiency, the need for fossil fuels to regenerate electricity, and the use of underground cavities as storage reservoirs have limited its development and use.

Energy storage (ES) plays a key role in the energy transition to low-carbon economies due to the rising use of intermittent renewable energy in electrical grids. Among the different ES technologies, compressed air energy storage (CAES) can store tens to hundreds of MW of power capacity for long-term applications and utility-scale.

Air4NRG will develop an Isothermal Compressed Air Energy Storage (Isothermal-CAES) system relying, among other things, on isothermal compression and expansion of air by liquid piston to solve the problems of the former CAES.

The CEER “European Green Deal” White Paper about long-term storage recommends that regulations establish a level playing field between long-term storage and other seasonal adequacy approaches (i.e., excess generation assets, flexibility, and storage).