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Superconducting Power Cable in Detroit
mgarraha writes: "According to a
Washington Post article, this summer
Detroit Edison
will lay 1200 feet of superconducting power cable near their
Frisbie substation, which serves 14,000 customers in downtown Detroit.
The cable, made by American Superconductor and Pirelli, consists of
silver-clad HTS ceramic ribbons woven around a pipe for liquid nitrogen." We've mentioned this particular project before. It's not room-temperature, but still interesting to see superconductors coming into large-scale, common use.
Koff-koff-koff OH man it's been a while.
Actually, it should be substantially cheaper. High power underground lines, including these ones, are usually oil cooled. Oil cooling is pretty expensive, since you have to somewhere dissipage quite a bit of heat. Liquid nitrogen is cheaper than water, and the superconductor doesn't produce any heat.
People are also looking at using this kind of wire in high power electric motors and transformers for the same reason -- not efficiency, but size and cost.
Using liquid nitrogen, while expensive, will certainly save money. Our current power grid can lose twenty percent or more power in transit. Keeping a constant flow of liquid nitrogen is pittances compared to the enormous savings of a 25% increase in power distribution. That's a LOT of power. Granted, we won't reap the benefits of this until after much of the United States has better power cabling, but this is just a start. |JH|
1. Pressure is released from room temperature Liquid nitrogen.
2. Liquid Nitrogen becomes gas.
... Wait, it can't become a gas unless it slurps up enough energy to cover it's latent heat of condensation. Enough energy get's absorbed to cause the surroundings to get cold (-195 Deg C. cold).
5. Cable gets cold and becomes a superconductor. Nitrogen is still piped around at room temperature or, more accurately, underground temperature. The only cold nitrogen was the stuff that was allowed to escape to become a gas.
Keeping
The power grid is so lossy, you can power a house by setting up a capture coil near a high tension line. Or, you can light up a florescent light by just holding it near one. We loose 20% of our generated power by the air and resistance loss from the power grid. If we replaced all high tension lines with this technology, we would have 15-20% more power without ever building a new power plant. Plus, we could efficiently move power where it is easy to make it (nuke, hydro, wind) to places it cant be made easy. With a super-conducting power rail from one coast to the other, we would have the ability to send power from one end of the nation to the other with less than 1% loss. This is only a dream with copper and Al cable.