LIQHYSMES – Liquid H2 and SMES for renewable energy applications

•A 2-stage Joule–Thomson-expansion is proposed for the intermediate H2 storage.•Depending on operating conditions, liquefaction losses may be 18–66 kJ/mol.•LIQHYSMES plants target long-term energy balancing and short-term power control.•Simulations using actual profiles demonstrate the anticipated buffering capability.•A small first experimental demonstration is now underway.

A new multi-functionality hybrid energy storage concept, LIQHYSMES, has been recently proposed. It combines the use of LIQuid HYdrogen (LH2) as the bulk energy carrier with much faster and efficient superconducting magnetic energy storage (SMES). The LIQHYSMES Storage Unit LSU integrates liquefaction and storage of H2 as well as the LH2-cooled SMES: A process for the intermediate storage of H2 in liquefied form is proposed, and alternative SMES designs are compared. The basic operational principle is simulated for a simple model case with two large LIQHYSMES storage plants supporting the transfer of renewable energy from one region of strong supply to a second one with a widely negative imbalance between supply and load. Losses of all plant components are analysed in terms of their relevance for the overall efficiency, and some cost issues are briefly addressed. A small first experimental demonstration is now underway and also briefly introduced.