If you're going to bring into the argument technologies which don't
exist and likely never will, like room temperature superconductors,
the other side is likely to start invoking space elevators made of
graphene or buckytubes or whatever the current high-strength dream
material is.
But actually, I don't think you need to. Wikipedia quotes
transmission losses of 3.5% per 1000 kilometers for high-voltage DC
power lines, which yields about 50% loss for going halfway around the
world. That's not an unworkable number; and it's probably mostly
resistance loss, which can be improved by using thicker conductors.
Prior to World War 1, there was a large school of thought that said
that the world economy had become so interdependent that the major
powers would never dare to go to war against each other. That school
of thought was so thoroughly destroyed that it has only recently
started to be revived. (It turns out that when going to war, "the
enemy depends on us" is viewed as an advantage which counterbalances
the disadvantage that "we depend on the enemy".) And that was with
major powers making the decisions; an electrical cable circling the
globe would have to cross some dodgy areas, giving control to actors
with little to lose. A considerable amount of interdependence among
nations is somewhat inherent to the modern technological world, but
this would be getting ridiculous.
On Tue, Mar 17, 2015 at 10:24:32AM -0400, Bill Claybaugh wrote:
Nobody is going to use existing superconductors for more than a few
kilometer (under the East River to Manhattan, for example, where the
savings in power loss justify the expense). Whether a room
temperature superconductor exists is obviously an open
question. Again, the point is that the large cost of power losses in
the existing grid (I estimate that at least 20% of all power
generated in North America is loss to heating up transmission lines.)
means there is a large economic incentive to finding a better
solution.
Geopolitics plays in any large power system, including SPS. The
counter view is that large international grids act as political
stabilizing systems, FWIW.
Bill
Sent from my iPhone
On Mar 17, 2015, at 5:46 AM, Norman Yarvin <yarvin@xxxxxxxxxxxx> wrote:
On Tue, Mar 17, 2015 at 03:54:22AM -0400, Bill Claybaugh wrote:
Again, the point is that such solutions are lower cost and
incremental to existing economic needs: as Keith has observed, power
loss in existing cable is expensive; which is why transmission
companies are experimenting with superconducting cable to replace
existing cable.
When one considers the practicality of running power cables cooled by
liquid nitrogen under thousands of miles of ocean, solar power
satellites start to seem like a reasonable project.
The vulnerability of a worldwide power grid to hostile acts would also
be most extreme. The Ukraine situation offers but a faint hint of the
opportunities for extortion that would arise from being in a position
to cut the world's electrical throat.