They conduct 150 times the electricity of similarly sized copper wires. However, because of technological difficulties, the commercial development of superconductor power-cable systems has been slow.
相比同样粗细的铜导线，他们的输电能力高达150倍，但因为技术困难，超导体输电的商业应用发展缓慢。
2
The electricity conduct to earth from the base of tower and copper cable.