The speed record of 581km/h marked by JR-Maglev is limited by relatively short length of the current test track (currently just 18.4km long, to be extended to 42km by 2013). While JR-Maglev is actually aiming at operating at 550km/h in service, TGV's record is rather a sales promotion and its actual service speed won't exceed 360km/h in the near future.
When it comes to energy efficiency, I guess JR-Maglev consumes more electric power than conventional rail systems at the same speed. JR-Maglev has to refrigerate liquid helium to maintain superconductivity of its magnets, and in general the linear motor is less efficient than the rotating motor because it cannot confine electromagnetic field in a small space.
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The speed record of 581km/h marked by JR-Maglev is limited by relatively short length of the current test track (currently just 18.4km long, to be extended to 42km by 2013). While JR-Maglev is actually aiming at operating at 550km/h in service, TGV's record is rather a sales promotion and its actual service speed won't exceed 360km/h in the near future.
When it comes to energy efficiency, I guess JR-Maglev consumes more electric power than conventional rail systems at the same speed. JR-Maglev has to refrigerate liquid helium to maintain superconductivity of its magnets, and in general the linear motor is less efficient than the rotating motor because it cannot confine electromagnetic field in a small space.