To generate a 400,000 Gauss magnetic field, approximately 40 Tesla is required. The energy needed to maintain this field is influenced by the properties of the magnet used, particularly its inductance and current. High-field electromagnets often utilize superconducting wire, allowing the power source to be turned off after reaching the desired field strength. For non-superconducting coils, voltage is necessary to maintain current, determined by the coil's resistance and current through it. An example is the NHMFL's 45T magnet, which consumes 33 MW of power.