HyLife – Microbial risks associated with hydrogen underground storage in Europe

Developing Europe’s energy system towards net-zero in 2050 as stated in the European SET Plan (20) requires a variety of innovative energy system solutions in which H2 will play a vital role. To secure sufficient and stable green H2 supply over time, storage of excess H2 is crucial to help avoid further consumption of non-renewables in high-demand seasons. A technological challenge is to find and operate flexible, large- scale storage solutions for H2. Underground/subsurface storage in caverns and reservoirs/aquifers has been proposed as a promising solution, but many questions on what will happen with H2 when injected into the living subsurface remain unanswered and overlooked. In close cooperation with energy companies, storage operators and service companies (see section 3) we want to advance the understanding of subsurface energy storage sites by assessing the most critical identified risk: microbial conversion. In our proposed project HyLife, we will focus on underground H2 storage and microbial activity inside the storage sites. Microbial activity can heavily influence storage viability, safety and economics by consuming H2 and producing the toxic, corrosive and explosive gas H2S. The possible microbial processes must be understood from a field-specific point of view and on an experimental level to properly estimate the risks, pinpoint favourable storage sites, and avoid or mitigate potential operational failures. This is important to secure a continuous and long-term energy supply despite intermittent renewable energy production, a key factor in achieving social acceptance of a renewable energy system. By including business assessment of the microbial risks and potentially needed mitigation efforts, the project brings in a valuable cross-cutting dimension, which is of great interest to the industry sector. The project goals are directly in line with the 3 European Green Deal, the European SET plan and the mission innovation of the CETPartnership to empower the clean energy transition, pool European knowledge and excellence and accelerate clean energy technologies. We will directly impact national and international policy makers as the new knowledge will be important for defining legal frameworks for full-scale deployment of H2 underground storage.