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Superconductors bringing power to the home

Normal cables could well be replaced by nitrogen-cooled superconductors

Those lucky Japanese – they get everything first. The PS3, Nintendo DS, Blu-ray and now superconducting home electricity cables.

From 2010, Tokyo-based electricity supplier Tepco will be delivering power through superconducting cables to homes and businesses in Yokohama in an experiment to see how efficient it is.

Resistance is futile

Compared to normal cables, superconductors allow almost no power loss. That's because they have zero electrical resistance and, therefore, none of the power is lost as heat given off during transmission across long distances.

Until now, the problem has been in creating superconducting wire that is long enough to do the job, but Sumitomo Electric believes it has managed that for Tepco.

High temperature

The first test will use 300m of the material and will deliver enough electricity for up to 500,000 homes to a substation for onward delivery.

Unlike low-temperature superconductors that need to be kept in dangerous and expensive liquid hydrogen, these high-temp versions need be cooled only with liquid nitrogen, which is relatively cheap and safe.

If Tepco makes the savings it predicts, it plans to expand the superconductor cable network around 2015, saving vast sums that would otherwise have been spent on building more conventional power cables.