[ExI] [Server-sky] Power sats again

Keith Henson hkeithhenson at gmail.com
Mon Jul 15 15:24:01 UTC 2013


On Mon, Jul 15, 2013 at 5:00 AM,
<extropy-chat-request at lists.extropy.org> wrote:

> ----- Forwarded message from Keith Lofstrom <keithl at gate.kl-ic.com> -----

>> From: Keith Henson <hkeithhenson at gmail.com>

> I would be interested in the assumptions that went into the power
> revenue numbers.

5 cents per kWh declining to 2 cents per kWh over ten years.  These
number are converted to capital cost at 80,000 times the cents per
kWh.  That's ~equal to 6.8% discount over 20 years run though a
levelized cost model.
http://www.eia.gov/forecasts/aeo/electricity_generation.cfm

The economic model doesn't sell electric power, it sells power
satellites to utility companies.

> The value of electrical power is highly dependent
> on time of day.  Here in the Pacific Northwest, power produced at
> times of low demand (say 2200 to 0600) can have negative value;
> the Bonneville Power Administration pays money to dispose of wind
> power produced at these times in resistors in the desert, to avoid
> spilling water over the dams and supernitrogenating the water,
> damaging the salmon.

I should note that hydro is unlikely to ever be displaced by SBSP.

> Time dispatchable power is very valuable, but the SBSP ground
> rectenna systems must be able to receive power from power sats at
> low elevation - long east-west dimensions.  Powersats near the
> 0100 (1AM) position in their GEO orbits will be close to useless.
> Rectennas under cloud cover (50% or more of the time) will get
> an attenuated beam (with lots of unhealthy off-axis scattering).

At 2.45 GHz, clouds don't cause much attenuation.  A heavy rainstorm
will cause some loss.  As you go up in frequency these problems get
worse.  Good point on the value of dispatchable power, but switching a
power sat from one rectenna to another doesn't seem like a good idea.
(Other than backup power sats being switched.)

Given that electric power isn't even the biggest chunk of humanities
energy needs, I think there will be an entirely different mode of
managing the electrical grid.  Load management rather than generation
management.  I.e., generate more power than the peak electrical grid
load, and send everything above current demand to making hydrogen for
synfuel production.

> Converting space power to high value product before shipment from
> orbit provides much more value.  Google search results generate
> revenue of $20 per kilowatt-hour of electricity consumed, while
> bulk off-peak power is worth less than $0.04 per kWh.

Fascinating.  But for all of Google's size, it's not nearly as large
as the energy market.

The market for bulk power, especially if you can convert it to liquid
fuels, is really large.  But it is also intensely price dependent.



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