The technology of delivering electric power through cables has hardly changed over the years. Almost invariably, the cables are made of copper, making them thick and prone to power loss due to resistance. Now, though, Sumitomo Electric Industries, Ltd. has developed a type of superconductive cable that can carry up to 200 times as much power as copper cable - and with electrical resistance of zero. The new cable is expected to be a boon for the environment, as it halves the amount of power loss experienced by conventional types of power cables. SEI hopes to put the cable into actual use and initiate sales by the end of 2006.