Superconducting Cable Can Increase our Electrical Supply
by Lloyd Alter, Toronto 
on 05. 8.06
As much as half of the electricity transmitted through those ugly overhead high-tension wires is lost through resistance. The dream has been to replace them with superconducting cables, which can be buried, are much smaller, and have no electrical resistance. The problem has been the very low temperatures required for superconductivity, needing expensive liquid helium for cooling. Now Sumitomo Electric Industries has developed a bismuth-based cable that goes superconductive at the high temperature of -200C (-328F)- that's toasty, warm enough for cheap liquid nitrogen. In May it will be tested in Albany, New York, connecting two power stations. The implications: if one gets more electricity out of the existing infrastructure, then you don't need new nuclear plants. You can tap distant wind, hydro or geothermal sources and transmit without loss. How much smarter is it to use what you have efficiently than to burn more coal or build more nukes. ::Trends in Japan
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While i like that the effort is being made, i question how much energy it will take to produce all that liquid nitrogen and then pump it along the transmision lines.
Aj
When you say that as much as half is lost, what does that include? I like the idea of these cables, but my understanding is that transmission losses (the long distance hight voltage lines) are on the order of 10%. I don't know what distribution losses (you local utility) are, but I would suspect they are not 40%.
So much for "Peak Copper" - use superconductive materials instead.
Commenter DW is correct- I took a line out of the original article and extrapolated from it. Overall, transmission losses are estimated at between 10 and 20%, depending on source. On very long lines from distant power sources, the loss can be 50% but that is not the overall average loss. I have retitled the post and tried to clarify it.
True, if we could transfer our AC current over superconducting wire - there'd essentially be no energy crisis. However, all of the high temperature superconductors (liquid nitrogen temperature) that i've seen are ceramics and are therefor very fragile.
It would be like trying to make a wire out of clay. Just doesn't seem practical to me.
Might be further out in the future but this sounds promising too.
http://en.wikipedia.org/wiki/Quantum_wire
It's much more complicated than just eliminating line losses. You still have losses due to un-matched loads, i.e. not all the electricity produced is actually consumed. The electrical generation facilites constantly overproduce to avoid brownouts (undervoltage) or blackouts (lack of current). This excess electricity has no effective storage medium, it's simply dissipated as waste heat in what is known as load banks.
I suspect the overall system losses to be much higher than 50% when you look at the combination of line (resistance) losses, phase change losses (all the AC currents are exactly synched, and can cancel a bit of each other out), transformer losses (on both ends, transmitting, and distribution), and wasted current that is diverted into load banks due to overproduction.
And all this from a typical Rankin Cycle Regenerative Steam turbine that is MAYBE 40% efficient on a good day for a coal or nuke plant. (same efficiencies, same cycle) A Natural Gas Plant does a bit better at 60-65% efficiency.
The whole system is very wasteful, and transmission over long distances only exacerbates the problem.
Heh, techno bullets scare me ("In 2023, it is discovered that the liquid nitrogen used to chill our electrical distribution lines (and is allowed to evaporatively bleed off as it warms) was contributing Global Soil Over-Nitrifaction").
C'mon room temperature superconductors!!! :) (another technobullet, but hopefully with no/far less downsides than trying to chill untold miles of wire with liquid nitrogen!!). True solution -> Just use less power!
This sounds great. Now we can build a heap of new nuke plants safely in the remote areas where they will be safest and not lose any electricity in transmission!
\hates this websites attitude to nuke power
Superconducting power lines are very old news.
A few miles of them were installed underground in downtown Detroit in 2000. Nothing ever came of it.
i think you have screwed up...
confusing half the power loss with half the power is lost.
the first is the stt of the originating source...the second sounds like nonsense to me