Hydrogen

Hydrogen

Hydrogen has emerged as a promising energy carrier and storage medium due to its high energy density by weight, ease of transportation, and versatility across multiple sectors. However, storing such highly flammable gas comes with essential obstacles to be addressed. When produced via electrolysis using renewable electricity, hydrogen is a carbon-free fuel that can be combusted or converted to electricity in fuel cells.

One key advantage of hydrogen is its long-duration, seasonal storage potential via compressed gas, liquefaction or novel solid-state media. This allows capture of solar energy produced in summer for use in the winter when renewable output is lower. Hydrogen can be stored in large quantities more compactly and economically than battery systems for long timescales.

For short-term storage, hydrogen fuel cells provide reliable on-demand electricity with just water as the emission. Major automakers like Toyota, Hyundai, FORVIA and GM are commercializing fuel cell electric vehicles (FCEVs) while stationary fuel cells are deployed for backup power, off-grid systems and grid support.

Hydrogen can also be blended into existing natural gas pipelines for storage and transport to consumption sites or employed in turbines for large-scale power generation. In Australia, the Hydrogen Park South Australia (HyP SA) project demonstrates hydrogen blending of 5% into the existing gas network, supplying over 700 homes with the aim of scaling up hydrogen production using renewable energy sources [1]. However, blending is less efficient for Europe as well as changes the quality of the gas consumed in Europe and may affect the design of gas infrastructure, end-user applications, and cross-border system interoperability. Therefore, the priority for the EU is to develop renewable hydrogen, produced using mainly wind and solar energy, with targets of at least 6 GW of renewable hydrogen electrolyzers in the EU by 2024 and 40 GW of renewable hydrogen electrolyzers by 2030 (EUR-Lex July 2020).

To conclude, Hydrogen's flexibility, scalability and emissions-free characteristics make it a compelling energy storage vector, suited for both short and long durations. While challenges in production, transport and conversion costs remain, hydrogen is expected to play an increasingly vital role in a renewable, decarbonized global energy system.

[1] Mahajan, D.; Tan, K.; Venkatesh, T.; Kileti, P.; Clayton, C.R. Hydrogen Blending in Gas Pipeline Networks—A Review. Energies 2022, 15, 3582. https://doi.org/10.3390/en15103582