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
On the other hand a friend of mine has a source that says transmission
losses are negligible.
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.
John Wood (Code 5550) e-mail: email@example.com
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,
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.
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?
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