Large-scale storage of hydrogen

TLDR

Large‑scale hydrogen storage is essential for a future hydrogen economy, yet salt‑cavern storage is limited by regional geology. The study reviews and compares large‑scale hydrogen storage options using thermodynamic and engineering criteria. The authors evaluate storage technologies by analyzing their thermodynamic properties and engineering feasibility. High‑density storage technologies such as liquid hydrogen, methanol, ammonia, and dibenzyltoluene provide superior density, cost, and safety, but their variable costs—driven by high electricity or heat demands—can be mitigated by storing electrolysis‑produced hydrogen during low‑price periods.

Abstract

The large-scale storage of hydrogen plays a fundamental role in a potential future hydrogen economy. Although the storage of gaseous hydrogen in salt caverns already is used on a full industrial scale, the approach is not applicable in all regions due to varying geological conditions. Therefore, other storage methods are necessary. In this article, options for the large-scale storage of hydrogen are reviewed and compared based on fundamental thermodynamic and engineering aspects. The application of certain storage technologies, such as liquid hydrogen, methanol, ammonia, and dibenzyltoluene, is found to be advantageous in terms of storage density, cost of storage, and safety. The variable costs for these high-density storage technologies are largely associated with a high electricity demand for the storage process or with a high heat demand for the hydrogen release process. If hydrogen is produced via electrolysis and stored during times of low electricity prices in an industrial setting, these variable costs may be tolerable.