What's wrong with this idea?

> Usually, when we read of the SPS scenario, there is a SPS and a
> dedicated rectenna farm.
>

That is only to illustrate the concept to somebody who never heard of it
before.

>
> To me, such a scenario negates two of the advantages of GSO, namely
> the wide footprint into which a SPS can beam power and the never
> varying power output of the SPS.
>

What do you mean by footprint ? The footprint is determined by the size of
the antenna, the idea is to be about a 10 kilometre diameter beam, that gives
us an achievable transmitter antenna size and a reasonable intensity at the
rectenna, hihg enough for useful energy conversion, but not so high that it
exceeds biological safety limits.

>
> 1.) A SPS for a city is designed for below peak power rating, and
> the neighboring SPS, which would be offset by perhaps a few
> timezones, can supplement with additional power to meet the peak
> power rating. Necessary premise: Peak power demand will ebb in the
> city providing supplemental power while it is rising in the city in
> need of the power. I also, realize that the microwaves coming in

That should work just fine. We can also switch the beam depending on time
of year, the demand cycle of a city will vary with time of year as well as
time of day.

In summer, the hotter cities need power for air conditioning.

In winter the colder cities need power for heating.

>
> from the SPS a few time zones away will be coming in at an acute
> angle, and thus not be as concentrated. And this might also cause
> havoc with issues like restricted airspace.

Airspace is not so much of a problem as the antenna geometry. The further
away from vertical, the larger and more elliptical the rectenna must be, and
the greater the atmospheric attenuation. At the 2.4 GHz band I am not sure
what the limit is, but at altitudes above about 50 degrees the rectenna will
start to beocme rather large and difficult to site.

> 2.) A super-sized SPS, with multiple transmitter arrays, serving
> multiple rectenna farms in a narrow longitudinal band. This could
> provide power balancing between different utilities. Also by

That sounds fine.

> extending this concept to a larger scale, could a Super-Size SPS
> serve multiple utilities across the hemispherical line, thus
> providing power to summer peak loads while the other hemispehre is
> experiencing winter?
>

Sure. What we are talking in effect is a global power grid. Something not
possible with conventional technology because of the huge cost of
transmitting power for thousands of kilometres. But for SPS, the cost of
switching a beam 5,000 or even 10,000 kilometres is zero.

>
> 3.) A transfer of microwave power to and from multiple orbiting SPS
> in order to take power where it is needed. This prevents designing
> SPS capacity for peak power load. Thus, a SPS orbiting above a
> longitude in the night, can beam a portion of its power across
> space, perhaps relayed by other SPSs, to a SPS above a daylight
> longitude. This SPS would receive the microwaves, phase them into

I do not see the value of relaying power from SPS to SPS. IT complicates the
system and reduces efficiency. Beaming power directly to Earth rectennas is
always the most efficient. Any single SPS can cover about 40% of the
Earth. You only need three SPSes to give 100% global coverage with some
overlap. Simply put the SPS'es where they are needed. They can be off by
10 or 20 degrees lognitude with negligible performance hit.

>
> its own transmission and beam them down to the rectenna. What effect
> would the microwaves have on the communication satellites KU band
> signals? Such a lateral transfer of microwaves would cut a swath
> through all of the uplink-downlink paths.
>

SPSes normally would be about 2.4 GHz. This would not affect Ku band at
all. There would have to be some review of the effect of harmonics.
But the SPS sends a narrow beam, and the Ku band downlink receiving station
would have to be within a few kilometres of the rectenna to even notice the
harmonics within the sidelobes.

Interference between comm-sats of the same frequencies is a much bigger
problem than interference between them and the SPS.

The biggest problem is that the best frequencies for SPS have now been
allocated to cell phone services.