Long-duration energy storage
Developing large-scale CAES and BESS infrastructure to support Europe's security of supply, grid flexibility and decarbonisation.
Introduction
AddiGen is a European long-duration energy storage developer, delivering large-scale CAES and BESS infrastructure to markets where storage is critical to grid reliability, flexibility and decarbonisation.
As renewable generation reshapes Europe's power system, the grid increasingly needs capacity it can call on for hours and days — not only seconds. AddiGen originates, develops, de-risks and finances storage at infrastructure scale, building toward long-term ownership of the assets that make the transition work.
Development platform
AddiGen operates a disciplined development platform. Projects move through one connected loop — and capital recovered from mature projects funds the next generation.
Sites are selected where grid need, salt geology and market design align — storage located where the power system requires it.
Sites are selected where grid need, salt geology and market design align — storage located where the power system requires it.
Permitting, environmental studies, grid connection applications and technical concept engineering are advanced in parallel.
Geotechnical confirmation, fixed-price EPC structures and route-to-market contracts remove uncertainty before capital is committed.
Projects are structured for European infrastructure capital, with bankable contracts and institutional-grade documentation.
Long-term partners are introduced at the right point in the project lifecycle to construct, own and operate the assets.
Realised capital is redeployed into the next generation of projects, compounding development capability.
The platform scales across markets, building a portfolio of long-duration storage infrastructure for Europe.
Why AddiGen
Four principles define how AddiGen originates, develops and delivers large-scale storage infrastructure across Europe.
AddiGen takes projects from origination through development, permitting, grid connection, commercial structuring and financing.
BESS provides shorter-duration flexibility while CAES addresses much longer-duration requirements.
Supported by experienced institutional investors with the financial strength to advance projects and make long-term decisions.
Building toward ownership and operation of storage assets that play a critical role in Europe's power system.
EU Projects of Common Interest
Currently developing 2 EU-designated Projects of Common Interest.
Projects
AddiGen develops grid-scale energy storage projects designed to operate as part of national and regional power systems.
PCI 1.32A large-scale CAES and BESS development in Ahaus, North Rhine-Westphalia — designated a EU Project of Common Interest (PCI 1.32).
PCI 1.16A CAES and BESS development within the Green Hydrogen Hub, Denmark — designated a EU Project of Common Interest (PCI 1.16), using green hydrogen as its fuel source.
Targets subject to permitting and final investment decision.
Technology
AddiGen deploys commercially mature technologies — engineered, bankable and proven at scale — rather than experimental technology.
| Attribute | BESS | CAES |
|---|---|---|
| Primary role | Fast response, grid services, balancing | Long-duration energy shifting, security of supply |
| Duration | Shorter duration — typically up to 4 hours | Multi-hour to multi-day |
| Renewables | Balances short-term variation | Integrates high shares of wind and solar |
| Grid role | Grid services | Security of supply |
| Typical use case | Short-duration flexibility | Shifting surplus power across hours and days |
| Technology maturity | Commercially mature | Commercially mature — decades of operation |
How CAES works
Compressed Air Energy Storage stores surplus electricity as pressurised air in deep underground salt caverns — and returns it to the grid when the system needs it.
Surplus electricity — often from wind and solar at times of low demand — drives compressors that push air into deep underground salt caverns at high pressure.
Compressed air is held in the geological salt formation, sealed and inert. Storage capacity is measured in gigawatt-hours and does not degrade between cycles.
When the grid needs power, air is released, heated and expanded through turbines that generate electricity — for hours or days at a time.
Technology selection
Technologies are selected against the needs of the power system, not the other way around.
Deployed at commercial scale for decades, with established supply chains and operating records.
Capacity scales with geology and grid need — from tens of megawatts to multi-gigawatt portfolios.
Infrastructure measured in multi-decade operating horizons, not product cycles.
Storage that enables higher shares of renewable generation across European grids.
A credible route to decarbonised long-duration storage, including green-hydrogen-fuelled operation.
Company
AddiGen acquired the project companies holding the Ahaus (Germany) and Green Hydrogen Hub (Denmark) storage developments, establishing a four-project platform across two European markets.
Our mission
"To build a leading European platform for long-duration energy storage, delivering the infrastructure that makes renewable power systems work."
Contact AddiGen
For enquiries regarding investment opportunities, partnerships, grid integration or our project pipeline, please get in touch.
