What is unusual about keeping a steady current flowing in a superconductor?

1. In an ordinary conductor the free electrons collide with atoms and lose energy to them. 2. Those losses mean a continuous power input is needed just to keep the current going. 3. A superconductor can carry a steady current with no continual supply of energy, which is a large energy saving. 4. Energy is not removed from a superconducting current either, so the third option describes nothing physical here. _Source: OpenStax College Physics (CC BY 4.0), Ch 20 "Electric Current, Resistance, and Ohm's Law", section Conduction of Electricity and Heat_