Context and overall objectives of the project
The transition towards a climate-neutral Europe requires reliable, long-duration energy storage solutions to balance the increasing share of intermittent renewable generation. Current dominant technologies, such as pumped-storage hydroelectricity, face geographical limitations, while existing Compressed Air Energy Storage (CAES) plants have historically suffered from low efficiencies, reliance on fossil fuels, and the need for underground storage. In this context, the European Union has identified the development of sustainable, efficient, and scalable storage systems as a strategic priority for energy security, competitiveness, and the achievement of the Green Deal targets.
Air4NRG addresses this need by developing an innovative Isothermal Compressed Air Energy Storage (I-CAES) solution, targeting a round-trip efficiency above 70%. The project will deliver two prototypes: a plug-and-play system in a standard 40ft container, providing over ten hours of storage, and a larger-scale 200 kW unit. Both are conceived as rare material-free, safe, and cost-efficient solutions, designed to be fully manufacturable within the EU and easily integrated into the grid through advanced energy management systems (EMS).
Project pathway to impact
The project follows a structured pathway:
Design and optimisation of the isothermal compression/expansion process, regenerative heat exchangers, and system control algorithms.
Prototype development and validation under industrial conditions, including testing in a relevant environment (TRL5) to demonstrate operational efficiency, reliability, and safety.
Sustainability and socio-economic validation, applying a life-cycle approach (environmental, economic, and social assessments) to ensure the technology’s viability and societal acceptance.
Market analysis and integration into European electricity grids, addressing regulatory, standardisation, and business model aspects to facilitate scalability and replication.
Exploitation, dissemination, and communication, engaging policymakers, industry, academia, civil society, and media to accelerate adoption, strengthen EU technological leadership, and ensure long-term competitiveness.
Through this pathway, Air4NRG is expected to:
Increase the availability and robustness of sustainable long-term energy storage in Europe.
Enhance energy system flexibility and resilience, enabling greater penetration of renewable energy.
Reduce lifecycle costs by up to 40% compared to lithium-ion batteries, while tripling service life.
Minimise environmental impacts, with an expected 60% reduction in carbon footprint compared to lithium-ion technologies and a land use reduction of up to 80% compared to pumped hydro.
Create new high-skilled jobs and stimulate the European energy storage value chain.
Role of Social Sciences and Humanities (SSH)
Although the project is mainly technology-driven, SSH integration plays a central role in ensuring societal acceptance and maximising impact. A Social Life Cycle Assessment (S-LCA) will be carried out to analyse stakeholder perceptions, societal readiness, and acceptance barriers, feeding into tailored communication and exploitation strategies. Furthermore, the project will explicitly consider gender equality, responsible research and innovation (RRI) principles, and the Sustainable Development Goals, ensuring that Air4NRG contributes to a just, inclusive, and sustainable energy transition.
