Friday, August 6, 2010

Room Temperature Superconductors

{Note: This post is #6 in a series of 12 where I review what Scientific American magazine has called the “12 Events That Will Change Everything”. See previous posts “Creation of Life”, “Nuclear Exchange”, “Extra Terrestrial Intelligence”, “Extra Dimensions”, “Polar Meltdown” and “False Dichotomy” for more information.}

The Event: Scientists will develop superconductors – wires used for electrical transmission that have almost no losses – that can operate at room temperature. The existing superconductors only work at extremely low temperatures ( -196 degrees C) which makes them impractical for normal use where transmission lines are typically 100s of kilometers in length.



The Impact: If room temperature superconductors become a practical reality, it would greatly increase the efficiency of the electrical grid. A typical transmission line will have losses around 10% – the electrical resistance of the wires results in some of the electricity creating small amounts of unwanted heat. While 10% may not seem like a lot, on a larger scale such as the province of Ontario, it can be the equivalent to one or two generating stations in use simply to compensate for the losses. These losses are accounted for and paid by the end use customers, so any reduction in these losses would be a financial savings to all electricity users, plus we would need fewer generating stations.



Superconductors can also be used to create “supermagnets” which could be used to levitate vehicles such as trains so they can glide along a track without touching it, greatly reducing the amount of energy needed to move it forward.



The Science: Research into superconductors has been going on for quite a while, with some early developments in 1986. However, those conductors needed to be kept extremely cold, which requires energy to keep the temperature down, so they don’t result in a true reduction in electrical use. In the past few years, some developments have occurred using iron based compounds, but they still need to be very cold to operate. When materials become very cold, electrons can move with very little energy which means the electrical resistance is lower.

Jac’s Analysis: Scientific American magazine gives this event a 50-50 chance of happening in this century. I’m a bit more doubtful, maybe less than 10%. Without getting too technical, the laws of physics are really against us on this one. Most of the matter in the universe does not conduct electricity very well – which is a nice built in safety feature if you think about it. It is this property that allows us to control the flow of electricity and shield ourselves from its lethal power by covering wires with rubber or plastic insulation. Trying to create a compound that has no electrical resistance seems a bit futile to me.

Our Reaction? Unless you are a power systems engineer or really interested physics, this topic is probably pretty boring. Even if they do develop something practical in the next decade, it will take 25 to 50 years before we can rebuild the electrical network. So, I’ll accept a brief yawn from most of you and move on to a more exciting topic.

Questions and comments?

1. Do you give much consideration to how much electricity you waste in your own home by leaving lights on when not needed?
2. Do you think this type of science is worth pursuing or should we focus on more efficient and cleaner ways to generate electricity?

Next week we look at the possibility of machines (robots) thinking for themselves.

Jac

4 comments:

  1. As an aside, I'm curious to know if there is research going on to make more environmentally friendly light bulbs (maybe even recyclable ones?)? The new high efficiency bulbs, though saving us a lot of electricity, are still bad for the environment when we have to get rid of them.

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  2. The short answer is yes. The compact fluorescent lights (CFLs) have trace amounts of mercury, as do all fluorescent lights, so they need to be disposed of properly. Newer technology like LEDs are coming out now in configurations similar to a standard light bulb. But they are expensive and don't give off as much light and the colour can be different than what we are used to. Hopefully more research will overcome these obstacles soon. In the meantime, CFLs are still a good choice since their reduced electrical usage means less emissions at the generating stations.

    Jac

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  3. Yes, we try to think about the electricity that we waste. We have purchased power bars that can be turned off easily at night so that several items that use electricity to keep those little clocks and lights on can be turned off. Do you think doing this small thing will really help?

    I think we should focus on cleaner and more efficient ways to generate electricity.

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  4. Every little bit of energy conservation is worth it. Even though it doesn't seem like much, if all 4.5 million electricity customers in Ontario each do just a little bit, it adds up to a whole lot. Keep up the good work!

    I personally favour nuclear generation as the best option for bulk power production. While it does produce radioactive waste, it's not that difficult to manage. The amount of waste created to power one home for one year is about the size of an almond. Solar is nice when the sun shines and wind power is OK when the wind blows, but we need bulk generation like nuclear or hydro dams for our base load. Event number 10 is about fission energy which is still about 20 years away if things go well. I'll explain that one a bit more in a few weeks.

    Thanks for your comments!

    Jac

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