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Re: Wireless transmission of power,

Original poster: Yurtle Turtle <yurtle_t@xxxxxxxxx>

I stand corrected. I didn't consider fuel, as we use
hydropower around here. Water to wire efficiencies are
pretty good, but I forget the exact number.


--- Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>
> At 03:30 PM 3/17/2005, Tesla list wrote:
> >Original poster: Yurtle Turtle <yurtle_t@xxxxxxxxx>
> >
> >Actually, we are involved in a multistate lawsuit
> >involving several hydroelectric providers over the
> >value of water in a lake to energy providers. I
> don't
> >remember the exact efficiency numbers, as I'm not
> in
> >the office today, but I assure you, it's
> significantly
> >higher than 10%. In fact, my former boss was
> involved
> >in a project which used excess electricity to pump
> >water into a reservoir to store "energy" then used
> it
> >to power turbines when they needed to generate
> >electricity. So they used hydropower to generate
> >electricity, which powered pumps, which then again
> >powered generators. This makes absolutely no sense
> if
> >you are losing 90% each iteration.
> >
> >Adam
> Typical power plant efficiencies for fuel in to
> electricity out are around
> 25-30%, and sometimes better
> For you thermodynamics folks out there, steam plants
> run 1000 psi+ steam at
> nearly 1000 degrees (F). That gives a Carnot
> efficiency up in the 60%+
> range. Gas turbine plants can be even better
> because the turbine inlet
> temp can be a lot hotter... 1400+C rejecting to
> 300K... that's 82% carnot
> efficiency, and because the conversion of fuel to
> heat into the engine is
> more efficient (no intermediate steam step).
> In reality, the prime mover is probably about 60%
> efficient. The
> turbogenerator is probably about 90% efficient.
> But, as long as oil, coal, and natural gas are
> cheap, there's really no big
> reason to push for higher efficiency or alternate
> power sources or
> distribution. Let oil get to $400/bbl and coal and
> gas comparable, and
> you'll see a real push for efficiency, particularly
> on the consumer
> side. Improving your refrigerator efficiency from
> 50% to 90% not only
> saves the fuel to produce it, it saves all the
> thermal losses along the
> way, as well as infrastructure costs.