Microbial risks associated with hydrogen underground storage in Europe - HyLife

Many renewable energy systems utilize “Power-to-Gas” technologies, which use renewable electricity to produce hydrogen (H2), a universal energy carrier. H2 can be utilized, transported or stored for later use for several industrial sectors like chemical industry, heavy transport and steel production.

To ensure a secure supply of H2 throughout the year, it is essential to have flexible, large-scale storage to balance expected fluctuations of energy-production and -demand. Underground/subsurface storage has been proposed as a favourable solution for mid-to long-term storage, due to the large available volumes that could hold up to 920 TWh; this would be sufficient for a mid-range scenario of 2,500 TWh of annual H2 demand in 2050 with at least 30% storage capacity (1, 2).

It is a known fact that many of these potential underground storage sites harbour diverse microbial communities and that H2 is not only a perfect energy carrier for human industry but also for microbial metabolisms. While microorganisms consume the H2, they can induce microbial-triggered risks including loss of the stored H2, risks to operational safety and deterioration in quality by H2S production, biocorrosion and changes of the reservoir properties (3).

As the demand for more H2 storage rises, it is therefore important to understand the extent of the microbial presence and activity within the different types of sites (salt caverns, porous media including aquifers and gas reservoirs).

HyLife will produce valuable insights on what types of microbes are present and how they will influence the stored H2 through extensive sampling across Europe.

Direct results will be a) aligned and tested methodologies to maximize comparability, b) an open database on detected microorganisms within the broad range of storage site conditions, c) microbial factors for field screening to minimize the risk when selecting sites.

We will also assess related environmental risks, test potential mitigation options and produce insightful techno-economic business analyses.