1.   But hopes for building a superconducting power line remained unfulfilled.

2.   Engineers are now installing a set of superconducting power cables beneath its streets.

3.   Experts say the line will demonstrate the practicability of large-scale superconducting power transmission and will be the first of many such lines.

4.   Further, it may at last be economically feasible to build superconducting power lines that would save enormous amounts of otherwise wasted electrical energy, Peterson said.

5.   The idea of superconducting power lines goes back decades, but until recent advances has been too costly to be practical.

6.   The main reason for wanting to install superconducting power lines in cities is not, perhaps surprisingly, to reduce transmission losses.