The Resource Basis of Magnetic Refrigeration

Emerging economies such as China and India are currently experiencing a "refrigeration revolution." Energy spent for domestic cooling is expected to outreach that for heating worldwide over the course of the twenty-first century. Magnetic refrigeration is an alternative cooling technology that works without gas-based refrigerants and has the potential to be significantly more energy efficient. We evaluate to what extent the raw materials needed to produce this kind of technology on a mass-market scale are critical in terms of demand and supply, thus identifying potential supply bottlenecks that might hinder the breakthrough of this promising technology. We assess the criticality of three promising magnetocaloric materials, that is, Gd-5(SiGe)(4), La(FeSi)(13), and (MnFe)(2)P), as well as of Nd2Fe14B, as the candidate permanent magnet material to drive the cooling cycle. The Gd-based alloys are disqualified as a mass-market refrigerant in terms of resource criticality, whereas La-and Mn-based alloys are much less problematic. Given the current state of technology and projected resource supply, Nd in Nd2Fe14B magnets would experience a significant bottleneck only at a later innovation stage, that is, when magnetic cooling technology would largely dominate the domestic refrigerator and air-conditioning market.