One method of energy storage that is notably absent from David Kramer’s “Better ways to store energy are needed to attain Biden’s carbon-free grid” (Physics Today, September 2021, page 20) is superconducting magnetic energy storage. SMES was studied extensively by Roger Boom and his group at the University of Wisconsin–Madison, beginning in the 1970s. Small SMES units have been built and operated successfully, which puts SMES ahead of some of the technologies mentioned in Kramer’s item.
One of the advantages of super-conducting magnets, as is well known, is that if they are sufficiently cooled, they can operate indefinitely. If properly designed, they also are not subject to the sort of catastrophic failure portrayed so colorfully in the James Bond film The Man with the Golden Gun.
