Hello, and only 20% finds its way to the load(s)? I wouldn't think so. Losses are not negligible. A properly planned distribution system provides for control of reactive volt-amperes (current out-of-phase with respect to voltage primarily due to inductive loads such as motors) at the source (generator) and load ends of the system. This is necessary to minimize transmission line power loss (proportional to the square of the current) in order to stay within the maximum current rating of the line and provide the most efficient energy transport.
BTW, it's my understanding that single wire earth return (SWER) systems are popular in (I asume the outback) Australia. Now that's a system to wonder about with respect to loss between the generator and loads. Sincerely,
John Wood (Code 5550) e-mail: snipped-for-privacy@itd.nrl.navy.mil Naval Research Laboratory
4555 Overlook Avenue, SW Washington, DC 20375-5337
Not negligable, not 80% either. According to my local utilility's annual report they generate about 7% more electricity than they get paid for - which I would be comfortable as accepting as the average of all transmission losses between generator and user. Your milage WILL vary.
I think you may have heard it incorrectly. When all issues are factored in, the total energy conversion for SOME generation systems can have overall losses that high, but not the TRANSMISSION losses alone. Oil fired power plants are supposedly the worst. First you have to factor the cost of finding and extracting the oil, pumping it to a port, shipping it to its destination, pumping and piping it to the power plant, the cost of making it burn (blowers etc.), the massive heat losses, the generator losses, then finally the transmission losses. So if you calculate the joules of energy in the raw oil as it sits underground, then add up all of the energy it took to get it to the power plant, then calculate the losses involved in converting it to electricity and finally that 7% loss in transmission, then calculate the total joules of energy available to you as electricity at the point of use, it could very easilly add up to 80% losses, maybe more!
The argument is used to put forth the idea that po>Hi all,
What was said "Can anyone tell me what proportion of Electricity generated at power
dealt with the transmission and distribution system.
Yes, if you include the effects of the thermal efficiency of a fossil plant, say 35% and generator efficiency -say 95% and also include the cost of digging up and processing ancient solar energy stored in the biological residue of plants and animals, the overall efficiency could be as you said.
Now, to be fair, apply this to a solar system using the same basis considering the efficiency of the solar cells, transmission or conversion costs, and the energy used in obtaining the material for making the solar cells and in the actual construction. Are you any better off in terms of efficiency ?
I'm not against renewable sources as we need to take advantage of such sources but if your point is that use of solar energy would result in less overall heat wasted because the energy is being provided anyhow without the addition of energy that was stored eons ago, then say so (and I would agree), but don't use an conversion efficiency argument. --
Don Kelly snipped-for-privacy@shawcross.ca remove the X to answer
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