As the world races to decarbonize its energy systems, the choice between transmitting green energy as electrons through high-voltage direct current (HVDC) lines or as molecules via hydrogen pipelines emerges as a critical decision. This paper considers this pivotal choice and compares the...

Rare earth elements (REEs) have many uses in the energy and defence industries, among others, and demand for them is set to increase rapidly in support of the low-carbon energy transition. Although the REEs are not geologically rare, China dominates the supply chain, accounting for 70% of global...