Proving the viability of underground hydrogen storage

What is the aim of this project?

This project under the Hydrogen TCP focuses on demonstrating the technical, economic and social viability of underground hydrogen storage (UHS). The project supports the acceleration of safe implementation of UHS through co-ordinated collaboration and knowledge dissemination, by bringing together research and industry organisations across the world and linking related scientific industrial and societal disciplines.

Many steps need to be taken before safe and responsible large-scale deployment and commercialisation of UHS becomes reality. Timely preparation is vital, as development will take many years and the demand for large-scale underground energy storage is expected to increase rapidly.

Three pilot projects already testing UHS are:

• HyStock (Netherlands): testing of pure hydrogen storage in salt caverns;
• Sun Storage, RAG (Austria): mixed and pure hydrogen storage in gas fields; underground methanisation using combined H₂ and CO₂ injection;
• Hychico (Argentina): mixed hydrogen storage in gasfields; underground methanisation using combined H₂ and CO₂ injection.

How could the project be explained to a high school student?

In future renewable energy systems, hydrogen could play a key role in transporting and storing energy. Energy storage will become more important because renewable energy sources such as wind and solar are not always available when needed.

Hydrogen can be produced by splitting water with renewable electricity via a process called electrolysis. As a fuel, hydrogen can be used in vehicles and to produce heat and electricity for industry and buildings. It can also be stored underground in large quantities for a long time to be used later when needed.

Hydrogen is already stored underground in salt caverns in a few places in the United Kingdom and the United States but these sites have not been tested to see if hydrogen can be rapidly injected and extracted as wind and sunshine vary. Hydrogen could be stored in gas fields but there is little experience of this option.

By bringing together national and international research projects, this project seeks to answer questions such as: how does hydrogen interact chemically with the rocks it is stored in? Will microbes in the underground reservoirs consume the hydrogen, introducing impurities? How does the hydrogen move in the pores of the underground reservoir? How much hydrogen is lost when it is injected and extracted?

How does the project help to achieve climate and energy goals?

• Provides flexibility in the energy system to support production and consumption of variable energy such as wind, solar and heating, increasing the efficiency of renewable energy in the final energy mix
• Contributes to the security of supply in future energy systems largely based on renewable energy sources
• Reduces greenhouse gas emissions in several economic sectors.

About the Hydrogen TCP

Established in 1977, the Hydrogen TCP works to accelerate hydrogen implementation and widespread utilisation in the areas of production, storage, distribution, power, heating, mobility and industry. Members benefit from the TCP’s global research outreach and robust industry participation.