...100 MW of Space Solar Power ...per single launch!

Controversy Flares Over Space-Based Solar Power Plans


Jeremy Hsu
space.com - Wed Dec 2, 10:15 am ET

"Solaren would then need to launch a solar panel array capable
of generating 400 megawatts. The total launch weight of all the
equipment would be the equivalent of about 400 metric tons,
or 20 shuttle-sized launches, according to Hoffert.

But Solaren says that it would just require four or five heavy-lift
rocket launches capable of carrying 25 metric tons, or about
one fourth of Hoffert's weight estimate. The company is relying
on developing more efficient photovoltaic technology for the
solar panels, as well as mirrors that help focus sunlight.

Solaren has not provided details on just how its technology
works, citing intellectual property concerns. But it expects that
its space solar power can convert to RF energy with greater
than 80 percent efficiency, and expects similar conversion
efficiency for converting the RF energy back to DC
electricity on the ground in California. The company also
anticipates minimal transmission losses from the space
to the ground."
http://news.yahoo.com/s/space/200912...olarpowerplans






The 'inevitable' is steadily becoming possible...imho.


Jonathan


s

On Dec 13, 4:41*am, "Jonathan" wrote:
Controversy Flares Over Space-Based Solar Power Plans

Jeremy Hsu
space.com - Wed Dec 2, 10:15 am ET

"Solaren would then need to launch a solar panel array capable
of generating 400 megawatts. The total launch weight of all the
equipment would be the equivalent of about 400 metric tons,
or 20 shuttle-sized launches, according to Hoffert.

But Solaren says that it would just require four or five heavy-lift
rocket *launches capable of carrying 25 metric tons, or about
one fourth of Hoffert's weight estimate. The company is relying
on developing more efficient *photovoltaic technology for the
solar panels, as well as mirrors that help focus sunlight.

Solaren has not provided details on just how its technology
works, citing intellectual property concerns. But it expects that
its space solar power can convert to RF energy with greater
than 80 percent efficiency, and expects similar conversion
efficiency for converting the RF energy back to DC
electricity on the ground in California. The company also
anticipates minimal transmission losses from the space
to the ground."http://news.yahoo.com/s/space/20091202/sc_space/controversyflaresover...

The 'inevitable' is steadily becoming possible...imho.

Jonathan

s

Nice, if there's somebody in orbit who can use 400 MW.

If you want to use it planet-side, you have to get it down here.

THAT creates problems.

A storage device has mass, which brings all the transport problems of
a safe re-entry and recovery.

A conduit would require materials with properties we have not
developed yet.

A beam would present an enormous safety and environmental hazard. You
could cook an Airbus in milliseconds with a 400 megawatt microwave.
That's about 200,000 heavy-duty microwave ovens - at once.

Tom Davidson
Richmond, VA

tadchem wrote:
[..]

Nice, if there's somebody in orbit who can use 400 MW.

If you want to use it planet-side, you have to get it down here.

THAT creates problems.

A storage device has mass, which brings all the transport problems of
a safe re-entry and recovery.

Anti-matter?

A conduit would require materials with properties we have not
developed yet.

A beam would present an enormous safety and environmental hazard. You
could cook an Airbus in milliseconds with a 400 megawatt microwave.
That's about 200,000 heavy-duty microwave ovens - at once.

Not so, actually - an Airbus weighs about 400 tons, call the exposure 1
kW/kg, or perhaps 1 degree C per second, so it would take several
minutes, not milliseconds, before the Airbus might start losing
structural strength. If it was flying rather than parked, the air would
cool it so much that it wouldn't be affected at all.

That's IF you can get it all into the Airbus, which is not even vaguely
likely - a typical ground station covers maybe a square mile, GEO is a
looong way away, and focussing enough energy at that distance to do any
real short-term damage would take a maser, not the typical microwave
transmitter used in these space solar power designs.

The exposure on the ground could easily be low enough to be short-term
survivable for an unshielded human, indeed it would be quite difficult
to get even that amount of power per unit area, and impossible unless it
was deliberately weaponised.

Getting the power down to the ground is tricky, but it's not at all
impossible from a technical or a political viewpoint.


But I don't believe the Solaren numbers on the required uplift mass,
they are too small by a lot, and even if they are correct it has to get
to GEO not LEO (a power station in LEO is pretty much useless), which
would take maybe 60 Shuttle launches, not 20.

At a conservative $100 million per Shuttle launch, that's $6 billion -
and at 10c per kWh it would take 68 years just to recover the launch
costs, ignoring interest - in practice you could never do it.



I don't think Space Solar Power is impossible BTW, but I don't think the
way Solaren are going about it will work, at least not anytime in the
near future.

I'd be looking at a maybe 50 gigawatt system instead, using mirrors,
boilers and turbines - possibly manned. And a much cheaper launch system.

-- Peter Fairbrother

On Dec 13, 11:18*am, Peter Fairbrother wrote:
tadchem wrote:
[..]

Nice, if there's somebody in orbit who can use 400 MW.

If you want to use it planet-side, you have to get it down here.

THAT creates problems.

A storage device has mass, which brings all the transport problems of
a safe re-entry and recovery.

Anti-matter?

A conduit would require materials with properties we have not
developed yet.

A beam would present an enormous safety and environmental hazard. *You
could cook an Airbus in milliseconds with a 400 megawatt microwave.
That's about 200,000 heavy-duty microwave ovens - at once.

Not so, actually - an Airbus weighs about 400 tons, call the exposure 1
kW/kg, or perhaps 1 degree C per second, so it would take several
minutes, not milliseconds, before the Airbus might start losing
structural strength. If it was flying rather than parked, the air would
cool it so much that it wouldn't be affected at all.

How long would the Airbus' avionics last in a 400 megawatt microwave
beam?

You can't fly those crates by the seat-of-the-pants. Knock out the
electronic fly-by-wire systems and the plane becomes a brick.

Tom Davidson
Richmond, VA

tadchem wrote:

On Dec 13, 11:18 am, Peter Fairbrother wrote:

Not so, actually - an Airbus weighs about 400 tons, call the exposure 1
kW/kg, or perhaps 1 degree C per second, so it would take several
minutes, not milliseconds, before the Airbus might start losing
structural strength. If it was flying rather than parked, the air would
cool it so much that it wouldn't be affected at all.


How long would the Airbus' avionics last in a 400 megawatt microwave
beam?

You can't fly those crates by the seat-of-the-pants. Knock out the
electronic fly-by-wire systems and the plane becomes a brick.

As Peter said, a microwave energy beam would be spread over an area
in the square kilometre range. This is not really for security's sake
it is because of basic physics making it impossible to focus a microwave
beam very tightly over long distances. The beam would be survivable
by an unshielded human being (or more likely by a bird flying through
it). The electronics in the jetliner are shielded by the hull of the
plane and will survive the beam even more so than the human wandering
into the beam. This is not a problem.


Alain Fournier

Alain Fournier wrote:
tadchem wrote:

On Dec 13, 11:18 am, Peter Fairbrother wrote:

Not so, actually - an Airbus weighs about 400 tons, call the exposure 1
kW/kg, or perhaps 1 degree C per second, so it would take several
minutes, not milliseconds, before the Airbus might start losing
structural strength. If it was flying rather than parked, the air would
cool it so much that it wouldn't be affected at all.


How long would the Airbus' avionics last in a 400 megawatt microwave
beam?

You can't fly those crates by the seat-of-the-pants. Knock out the
electronic fly-by-wire systems and the plane becomes a brick.

As Peter said, a microwave energy beam would be spread over an area
in the square kilometre range. This is not really for security's sake
it is because of basic physics making it impossible to focus a microwave
beam very tightly over long distances. The beam would be survivable
by an unshielded human being (or more likely by a bird flying through
it). The electronics in the jetliner are shielded by the hull of the
plane and will survive the beam even more so than the human wandering
into the beam. This is not a problem.

That's correct. The beam power density will be about one-fourth the
solar constant. Even then, the aircraft hull is a perfect Faraday cage
against the frequencies of the beam.

The safety issues are overblown (the economic issues are not).

tadchem wrote:
On Dec 13, 11:18 am, Peter Fairbrother wrote:
tadchem wrote:
[..]
Nice, if there's somebody in orbit who can use 400 MW.
If you want to use it planet-side, you have to get it down here.
THAT creates problems.
A storage device has mass, which brings all the transport problems of
a safe re-entry and recovery.
Anti-matter?

A conduit would require materials with properties we have not
developed yet.
A beam would present an enormous safety and environmental hazard. You
could cook an Airbus in milliseconds with a 400 megawatt microwave.
That's about 200,000 heavy-duty microwave ovens - at once.

Not so, actually - an Airbus weighs about 400 tons, call the exposure 1
kW/kg, or perhaps 1 degree C per second, so it would take several
minutes, not milliseconds, before the Airbus might start losing
structural strength. If it was flying rather than parked, the air would
cool it so much that it wouldn't be affected at all.

How long would the Airbus' avionics last in a 400 megawatt microwave
beam?

You can't fly those crates by the seat-of-the-pants. Knock out the
electronic fly-by-wire systems and the plane becomes a brick.

Indeed, the power level in the beam is above the FAA standards -
aircraft would be required to avoid the area.

However if there are only a few beams, say six in the US, and each
exclusion area would be about 15 miles across, and probably located far
from airports - not a big problem, eg you can't fly over Area 51 or
whatever nowadays.

I was just pointing out that the aircraft, even a composite one,
wouldn't melt or anything like that!

-- Peter Fairbrother

Peter Fairbrother wrote:
I was just pointing out that the aircraft, even a composite one,
wouldn't melt or anything like that!

I was more worried about the microwaves going right through the
composite parts of the aircraft and hitting the people and electronics
inside of it.
As someone pointed out earlier, a all-metal aircraft works like a
Faraday Cage and shields its interior from the microwaves...although I'd
expect some pretty impressive electrical displays off of the static
discharge wicks at the wing and tail tips as the plane itself will act
like a rectenna for the microwaves, and that electrical energy has to go
somewhere.
It's best just to have aircraft just steer clear of the beam.

Pat

Peter Fairbrother wrote:
I was just pointing out that the aircraft, even a composite one,
wouldn't melt or anything like that!

There's another thing to consider here... if the composite material uses
carbon fiber in its construction (most aerospace composites do) there
is a problem as carbon fiber is electrically conductive, and hitting it
with microwave energy might cause it to arc at the ends of the fiber in
the same way a metal bread bag tie will in a microwave oven.
(Any long thin metal object works like a antenna for the microwave
energy, and starts emitting high amperage electricity at the ends that
will cause them to melt in a spectacular light and sound show*)
Although the microwave flux in the beam would be very low, the
individual carbon fibers could be several hundred feet in length, and
that could give them the antenna area needed to build up a very large
electrical charge even in a low energy microwave environment.

* You wreck your microwave oven trying this, it's not my fault - and the
fusing steel of the wire tie is hot enough to melt right into the glass
tray you put the food on.

Pat

On Dec 14, 8:12*pm, Peter Fairbrother wrote:
tadchem wrote:
On Dec 13, 11:18 am, Peter Fairbrother wrote:
tadchem wrote:
[..]
Nice, if there's somebody in orbit who can use 400 MW.
If you want to use it planet-side, you have to get it down here.
THAT creates problems.
A storage device has mass, which brings all the transport problems of
a safe re-entry and recovery.
Anti-matter?

A conduit would require materials with properties we have not
developed yet.
A beam would present an enormous safety and environmental hazard. *You
could cook an Airbus in milliseconds with a 400 megawatt microwave.
That's about 200,000 heavy-duty microwave ovens - at once.
Not so, actually - an Airbus weighs about 400 tons, call the exposure 1
kW/kg, or perhaps 1 degree C per second, so it would take several
minutes, not milliseconds, before the Airbus might start losing
structural strength. If it was flying rather than parked, the air would
cool it so much that it wouldn't be affected at all.

How long would the Airbus' avionics last in a 400 megawatt microwave
beam?

You can't fly those crates by the seat-of-the-pants. Knock out the
electronic fly-by-wire systems and the plane becomes a brick.

Indeed, the power level in the beam is above the FAA standards -
aircraft would be required to avoid the area.

However if there are only a few beams, say six in the US, and each
exclusion area would be about 15 miles across, and probably located far
from airports - not a big problem, eg you can't fly over Area 51 or
whatever nowadays.

I was just pointing out that the aircraft, even a composite one,
wouldn't melt or anything like that!

"Exclusion zones" are not foolproof. We have had several cases of
unregulated aircraft inadvertently violating the Washington D.C. no-
fly zone recently.

I'm sure that would be of great consolation to the families of the
victims.

Tom Davidson
Richmond, VA