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Post by rsmith7 on Mar 3, 2012 11:21:03 GMT 1
What are the merits/de-merits concerning DC current transmission?
I was led to believe it was impractical over long distances yet it appears undersea cables tend to carry DC. I ask in the context of shifting solar power from equatorial latitudes to where it's needed.
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Post by StuartG on Mar 3, 2012 12:37:47 GMT 1
It was a new one on me, but this is the explanation ... en.wikipedia.org/wiki/High-voltage_direct_current"... For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. For underwater power cables, HVDC avoids the heavy currents required by the cable capacitance. ..." That sums it up. The capacitance in the system makes for a large power loss in the wires, that means the power company have to make more power [more cost] at the generator end to provide the customer's needs. en.wikipedia.org/wiki/Power_factorI forgot to say the power lines underground/water lay close together and have a capacitance between them, they also have an inductance between them, all that means a power loss before any chargeable work is done. For small distances it doesn't matter so much, but when hundreds of miles are counted, it does. So with DC there is no loss in the cable from capacitance, DC doesn't flow across plates, and there is no changing magnetic field to induce voltage in the opposite wire. Same difference with electric versus petrol/diesel. On short journeys with lots of stop starts and a small distance from home [milk float], then electric is ideal. For long journeys not so. Thanks for pointing that up, it's interesting.
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Post by StuartG on May 10, 2012 20:50:20 GMT 1
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Post by marchesarosa on May 11, 2012 10:06:50 GMT 1
Depending on the Arab lands for energy from solar is as bad as depending on them for oil.
Regarding the Berbers, this is just one of the MANY examples of muslim states routinely discriminating against their ethnic and religious minorities. Incidentally, did you know that the Berbers, before they were subject to the onslaught of Islam, were caucasian? Hannibal and St Augustine of Hippo were Berber.
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Post by marchesarosa on May 11, 2012 10:12:29 GMT 1
What is needed for efficient electricity transmission is a cheap, room temperature super conductor.
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Post by jonjel on May 11, 2012 11:24:27 GMT 1
Not another 'not yet invented' product, please MR!
Please spare me from the waterproof glue that washes off, the internal combustion engine which does 500MPG at 70MPH, and the battery that charges in sunlight in 10 mins and will power your house for a week!
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Post by StuartG on May 11, 2012 12:57:57 GMT 1
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Post by jonjel on May 11, 2012 14:05:34 GMT 1
Still a long way to go SG, but I concede they have got from liquid helium up to liquid nitrogen temperature.
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Post by marchesarosa on May 11, 2012 16:12:42 GMT 1
Maybe we just need small scale efficient on site electric generation, from gas, say?
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Post by Progenitor A on May 11, 2012 17:43:17 GMT 1
Maybe we just need small scale efficient on site electric generation, from gas, say? No.That idea is bad economics Producing thousands of small scale generators is far more expensive than building a few large scale generators in both capital costs and maintenance costs That is why windmills are so expensive and why they are only feasible with government subsidies
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Post by StuartG on May 11, 2012 18:10:57 GMT 1
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Post by rsmith7 on May 15, 2012 18:58:35 GMT 1
The solution to the energy problem is simple. Outlaw the green movement.
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Post by StuartG on May 16, 2012 0:24:41 GMT 1
'Outlaw the green movement' I agree with Your sentiments, but driving it undergropund would make it more 'trendy'. In the real world, that I am subject to, most people don't even know what green is, except a colour. The movement is a result of the decadence of recent years. It should become less of lobby as more poverty and financial hardship takes hold. Stopping any charitable status would be more effective. It's a 'nice little earner' and power base for its members. The word 'green' when used to describe the adherents, for me conjures a picture of a pastey face little soul, lacking any real character and serving as a veneer, when goaded by me, for a total intolerance for anything other than his own silly and unreal point of view. Other than that they're great!
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Post by marchesarosa on May 16, 2012 9:15:34 GMT 1
Greens have taken over benign environmental movements and after the failure of "socialist" experiments round the world, turned them into vehicles for their own totalitarian values and hatred of the West.
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Post by rsmith7 on May 16, 2012 9:38:53 GMT 1
Greens have taken over benign environmental movements and after the failure of "socialist" experiments round the world, turned them into vehicles for their own totalitarian values and hatred of the West. A very accurate and concise description.
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