A device for supplying electric energy to at least one superconductor, with the superconductor being cooled in a cooled region to at least one predetermined temperature for achieving superconductivity, includes at least one electric energy source, and a transformer for transferring electric energy between the at least one energy source and the superconductor. The cup member has a recessed portion offset outwardly from the sidewall, and a slotted opening formed in the recessed portion which extends along a length of the cup member. Operation of the distillation system enables production of esters including biodiesel and other biofuels in an economically advantageous manner.