Microbial risks associated to hydrogen underground storage in Europe

Developing Europe’s energy system towards net-zero in 2050 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. In close cooperation with industry (energy companies and storage operators) we want to advance the understanding of subsurface energy storage sites by assessing the most critical identified risk: microbial conversion. Microbial activity can heavily influence storage viability, safety and economics by consuming H2 and producing the toxic 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.
The main objective of HyLife is to “validate the suitability of European subsurface structures (caverns/reservoirs) as safe and economic viable H2 storage sites by systematically investigating the potential microbial reactions and identifying key influencing parameters.”