[Server-sky] [ExI] Power sats again

Keith Lofstrom keithl at gate.kl-ic.com
Fri Jul 12 20:28:39 UTC 2013

On Fri, Jul 12, 2013 at 04:41:05PM +0200, Eugen Leitl wrote:
> ----- Forwarded message from Keith Henson <hkeithhenson at gmail.com> -----
> Date: Thu, 11 Jul 2013 20:04:15 -0700
> From: Keith Henson <hkeithhenson at gmail.com>
> To: extropy-chat at lists.extropy.org
> Subject: [ExI] Power sats again
> Reply-To: ExI chat list <extropy-chat at lists.extropy.org>
> Gave an hour talk at Google today on the new breakthroughs that have
> reduced the startup cost to $60 B, the time to first power sat on line
> to ~7 years and raised the ten year ROI to 500%.  It also has the
> potential to keep the CO2 somewhat below 450 ppm.
> Was well received.
> I can send a draft of the article the talk was based on if anyone is interested.

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

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).  

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.


Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993

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