RE: Solar power

Robert J. Bradbury (
Wed, 7 Jul 1999 10:25 PDT

> "O'Regan, Emlyn" <> 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