Large magnets with superconductive windings could serve to perform a power system function analogous to pumped storage hydro. A conventional Graetz bridge converter as used in dc transmission provides an ideal interface between the three-phase power system and the superconductive magnet or inductor. Such Inductor-Converter or I-C units, when properly controlled, provide significant power system benefits. Power reversibility is achievable within a few cycles without switching. Power system electromechanical oscillations can be damped effectively. Computer studies reveal that this damping capability may be useful even with smaller inductor sizes when energy storage in large amounts is not the primary objective. In sizes greater than 1, 000 MWh, economic studies show promise.