RE: Solar power

From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Wed Jul 07 1999 - 11:25:00 MDT


> "O'Regan, Emlyn" <Emlyn.ORegan@actew.com.au> wrote:
>
> It's just come to mind that I remember mention of an idea some time ago, to
> extend the national electricity grids into a huge world-wide power grid,
> which might sort out fluctuations in supply around the world, make solar
> power more feasible (the sun's shining somewhere), and create a global
> electricity market where the countries best placed to produce power would be
> able to do it.

> Anyone know anything about this?

Its an engineering & return-on-investment problem . Utility companies
had an incentive to build the grid to increase reliability
and do load balancing. Then it became clear it could also
be used to buy power from the lowest cost source (after it
became clear that building nuclear plants was a big money pit).
Now, the East & West coasts in the U.S. buy a lot of cheap
hydroelectric power from Canada. In Europe, most of the
natural gas (and presumably power from that), comes from Russia.
Since there were cheap power sources and markets with a high cost
of electricty, building the grid/pipelines made sense.
All the U.S. government now is removing the monopoly from the
local distribution network. (So the consumer can in effect
buy his power directly from the hydroelectric producer).
This is what they have done with long distance telephone
service are attempting to do with the local telephone service
as well. [They still haven't gotten it quite right with cable
unfortunately, though court decisions may have recently fixed it.]

Power transmission over long distances is done (cost effectively)
with naked cables with enough air between them to function as an
insulator. Unfortunately salt water has this nasty property that
it conducts electricty. So to engineer undersea electrical cables
they would need to be have a lot of insulation (thick & heavy)
and you would need very high quality manufacturing process (for
reliability). We've had about 100 years of development to get
cost effective and reliable undersea telephone cables and those
run at relatively low power *and* we ended up switching from
eletrical signals to light. The engineers did and still do put
a lot of extra pairs in the cables to make sure they would continue
to have something that worked after 20 years. Can you see this
being done with high voltage cables?

Since solar power (as a power source), isn't cost effective right
now, undersea transmission of the power from the light side of the
planet to the dark side would only make things worse. Think of
the transmission losses! Even if we has HT superconducting cables
the problem of circulating that much LN2 under the ocean is not
trivial.

The average home has enough surface area to supply your power needs.
My electric bill says my average daily consumption is ~40 KWh.
An average house, say ~200 m^2 (home surface area) * 500 W/m^2
(average solar insolation) * .15 (conversion efficiency) * 8
hours / day = ~120 KWh.

You have to have a storage system and since these aren't very
efficient, the approach of selling "day" power to the utility
(for business use), while buying it back at night (for home
use) allows the utility to become primarily a resource storage
and distribution manager rather than a production manager.
They can build the big flywheels or high heat capacity salt
storage units for load balancing. Of course if you are a true
libertarian, you don't want the utility involved at all and have
to shell out some extra bucks for your personal power storage unit.

The problem is getting the cost of the solar cells to drop by
a factor of 2 to 3 (which is likely to be by 2010-2015 given
current trends). If we got serious about minimizing our
environmental impact (global warming, salmon loss, etc.) and
factored the hidden costs of fossil fuels/hydroelectric into
electrical production. then it might happen much sooner.
Germany seems to be buying photovoltaic power from the consumer
at $.11/KWh which is something like twice the market rate.

Now, of course to get the PV module costs down low enough
you have to get the manufacturing volume high enough and
that means that free market forces will only work over a
very long period. So the governments *are* subsidizing
both the R&D and the purchase of the PV modules through
various mechanisms. [Bad governments... we should
wait for the free market system to work it all out....]

Now, for something completely different -- what happens
if the cryonics people seriously thought about the problem
of low-cost long term preservation? If you were to make
an up-front investment in solar cells and an LN2 production
production facility, I suspect you could drop the long
term storage costs significantly! After you amortize
the investment in the equipment, your LN2 is essentially
for free and you resumably have a relatively low cost
for the workers who have to periodically top off the
tanks (though this could be automated as well)...
This makes sense, since controlling your own production
and using the sun as your power source increases your
disaster/political-wind-shifts tolerance.

Would more people go in for cryonics if you were to drop
the cost by an order of magnitude? (Say from 100K to
10K? What about 1K (which is below the cost of a
funeral...)?

Robert Bradbury



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