Power transmission losses

Hi all,
Can anyone tell me what proportion of Electricity generated at power
stations is actually delivered to the consumer?
I heard on the radio that 80% of electricity generated is lost in
transmission losses.
On the other hand a friend of mine has a source that says transmission
losses are negligible.
Any ideas?
John Smyth
Sydney Australia
Reply to
John Smyth
Loading thread data ...
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
Reply to
J. B. Wood
So that's what's causing global warming!
Line loss can be quite large over long distances, up to 30% or so I believe.
Reply to
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.
Reply to
Bill Shymanski
------------ Typically 5-8% generator to customer. depending on the system- distances, interconnections, etc. 10% is extremely high and 30% is ridiculous.
Reply to
Don Kelly
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 point-of-use generation, such as solar panels on your roof, are actually more cost effective when you look at the total picture. But we typically don't really look at the total picture. We need more electricity every day that the sun could deliver even if the entire land surface of the earth were covered with solar cells. So we must have all that waste to enjoy our modern way of life. using solar power is definately better for the planet, but the cost of supporting those massive losses is more easilly borne by being amoritized by the billions of people using small amounts. So if you can afford solar panels, by all means do it! It doesn't however get you off the hook for your part of the cost of losses for the rest of the world.
Reply to
Bob Ferapples
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 ----------------------------
Reply to
Don Kelly
News to me.
Assuming 1kW peak midday solar energy per sq metre (Which is what we get here in Australia) then each square km would receive 1000 MW peak.
Discount that by solar panels energy efficency and you've still got a hell of a lot of energy.
I've heard people say that here in Australia we could provide 100% of our electricity using conventional technology with a solar array 10 km X 10km.
So how much is global electricity demand anyway?
John Smyth Sydney Australia
Reply to
John Smyth

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.