Project USS 2030

Underground Sun Storage 2030

Overall approach

Underground Sun Storage 2030 project investigates and demonstrates a seasonal storage option for renewable energy as pure hydrogen storage in suitable underground gas reservoirs. Based on scenarios with 100% renewable energy in the electricity system it becomes obvious that storage options in multi TWh scale and in multi GW scale in terms of installed power are necessary. Pure hydrogen storage can safeguard constant admixture of renewable gas to the natural gas system and can provide security of supply of green hydrogen for the hydrogen-based parts of the economy in the future. 


Underground Sun Storage 2030 is a flagship project that is researching a solution for large-scale seasonal storage of renewable energy. The renewable energy generated will be stored in the form of pure hydrogen (H2) in depleted natural gas reservoirs. Current energy system models predict that there will be too much load in the electricity network during summertime. In contrast, fewer sunshine hours and low water periods in wintertime will cause power shortages. This gap cannot be closed by either starting up fossil-fuelled power plants or by electricity imports from neighbouring countries, who are expected to face similar challenges. Hence, there is the need to shift multiple TWh of energy from summertime to wintertime. With respect to the objectives of Underground Sun Storage 2030, RAG Austria AG has gained significant experience in injecting and storing hydrogen in natural gas reservoirs in a previous project (see figure on the bottom). 

Thus, together with this renowned partner from industry and Austrian research institutions various utilization pathways for the stored hydrogen will be investigated. These include:

  • Hydrogen admixture in the natural gas grid
  • Direct usage of hydrogen in the energy-intensive industry (grid-based supply)
  • Cleaning and upgrading to have high purity hydrogen for industry (non-grid logistic solutions)

The project Underground Sun Storage 2030 is unique world-wide. Due to the conducted field test, the project will achieve valuable results concerning the seasonal storability of renewable energy in the form of pure hydrogen. Technical and scientific investigations will be completed by modelling future electricity systems scenarios as well as through techno-economic analysis. As an interdisciplinary project, this includes demonstration of several technological approaches. Underground Sun Storage 2030 is part of the Energy Model Region WIVA P&G and is a basic requirement for a secured development of a hydrogen-based economy. The utilization of underground porous reservoirs for hydrogen storage purposes is also documented in the long term strategy 2050 – Austria according to Regulation (EU) 2018/1999 of the EP and of the Council on the Governance of the Energy Union and Climate Action.



Project runtime:

2020-07-01 to 2025-06-30 (48 months)

Funding scheme:

Energy Model Region (“Vorzeigeregion Energie“) of the Austrian Research Promotion Agency (FFG)

The Hydrogen Initiative Flagship Region Austria Power & Gas (WIVA P&G) is funded by the Austrian climate and energy fund and runs within the scope of the program „Vorzeigeregion Energie“. The project USS 2030 is funded by the FFG (contract no. 880764).

Project consortium: