Energy Satellite

No single project... will be as impressive to mankind,
or more important for the long range exploitation of space

Proponents claim that a 5Gw 'energy satellite'
could have a mass of as little as 10000t (about the
weight per area of an umbrella, or thick cardboard).
The amount of natural gas necessary to generate
that 5GW, for one month, is well in excess of the
amount needed to rocket that 10kt to orbit.
Were rockets, # for #, as inexpensive as locomotives
(as a German general believed should be the case) this
panacea would be a no brainer. Clean, wireless power
from the sun and a grateful world for a hundred generations.

Malthus cheated again.

We need to replace the phrase 'on paper' with
'as demonstrated'.

We need to find out:

How light can a pvwithreflector be made?

How long can it last?

How cheap to toss it into orbit?


Is there anything practical that can be done with
the power generated, short of the 5Gw necessary for
a practical 'ES'?

"Totorkon" wrote in message
...
No single project... will be as impressive to mankind,
or more important for the long range exploitation of space

Proponents claim that a 5Gw 'energy satellite'

Rubbish.

To generate 5Gw of electricity could be done by simply mounting solar PV
panels on the roofs people's homes. And it would be a considerably less
expensive option too (no launch vehicles; no propellant etc - oh, and the
cells don't have to be 'space-qualified' either).

Alan Erskine wrote:

To generate 5Gw of electricity could be done by simply mounting solar PV
panels on the roofs people's homes. And it would be a considerably less
expensive option too (no launch vehicles; no propellant etc - oh, and the
cells don't have to be 'space-qualified' either).


What fun would that be? :-)
Seriously, there is a basic problem with that approach, and it's called
night.
To get the concept to work right, we would need to run the US on stored
power at night.
So, until we get those superconducting electrical storage systems they
were talking about back in the 1990's, we have a problem...but one which
a GIANT SPACE MIRROR could solve!
Yes, a giant space mirror could give the United States SUNSHINE 24/7!
Okay, there may be some minor ecological impact from an idea like that,
but bats will just have to learn to fly in daylight or die off.
Moths are seldom as pretty as butterflies, and hard to see at night
anyhow, so no big loss there either.
Don't even get me started on owls.
In fact, all the creepy, oddball, and substandard animals seem to come
out at night, and our nation would no doubt be better off with all of
them extinct.
As for plants releasing O2 by day and CO2 at night...well, it's about
time they become part of the _solution_ to global warming rather than
the _problem_.
By doubling up their O2 production, we will soon have a healthy
atmosphere that is around 40% oxygen, which will make lighting the
barbecue far easier.
And once that barbecue is going full blast, we can cook those gourmet
cave-raised bats on it.
Or smelt steel to make arrowheads for our starving owl hunts.
Yes, the GIANT SPACE MIRROR will solve all of our problems. ;-)

Marvin The Mirrorman

In sci.space.policy message ke7Vl.15507$y61.8817@news-
server.bigpond.net.au, Tue, 2 Jun 2009 10:33:52, Alan Erskine
posted:

To generate 5Gw of electricity could be done by simply mounting solar PV
panels on the roofs people's homes. And it would be a considerably less
expensive option too (no launch vehicles; no propellant etc - oh, and the
cells don't have to be 'space-qualified' either).

I have heard that to be the most dangerous form of electricity
generation - because of all the people who fall off the roof while
fixing it.

--
(c) John Stockton, near London.
Web URL:http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, & links.
Correct = 4-line sig. separator as above, a line precisely "-- " (SoRFC1036)
Do not Mail News to me. Before a reply, quote with "" or " " (SoRFC1036)

On Jun 2, 3:33*am, "Alan Erskine" wrote:
"Totorkon" wrote in message

...

No single project... will be as impressive to mankind,
or more important for the long range exploitation of space

* *Proponents claim that a 5Gw 'energy satellite'

Rubbish.

To generate 5Gw of electricity could be done by simply mounting solar PV
panels on the roofs people's homes. And it would be a considerably less
expensive option too (no launch vehicles; no propellant etc - oh, and the
cells don't have to be 'space-qualified' either).


A house must have a large southern exposure, preferably
with a roof peaked at the proper angle. Forget planting
shade trees.

In places like Germany and Spain, the sun is harvested
on farmland and desert. A tracking system can inprove
efficiency by 50% but takes more area to prevent collectors
from shadowing each other.

It takes almost 10 sq mi to generate an average of half
a GW. A bit more than that area could harvest ten times
that energy in space. Under the rectenna the sunlight is
the same, suitable for crops or even cattle (tin foil hats
might become popular...just to be on the safe side).

The same InGaN pv cells that can operate at high
temperatures are also resistant to radiation. The area of
the high cost pvs can be minimized by ultralight reflectors,
perhaps by a factor of over ten.

The claim of proponents that 2kg/kW is a reasonable mass
looks difficult when you consider that half a GW of generation would
have a mass of 100 tons, that's 50000
the output of Dawn's arrays on its way to Vesta and Ceres.

But who is to say if nobody has tried.

Totorkon wrote:

A house must have a large southern exposure, preferably
with a roof peaked at the proper angle. Forget planting
shade trees.


Depends on the height of the house - even up here at around 45 degrees
north latitude, a two-storie house could provide reductions of cooling
costs in the summer when its roof pitch matches the maximum exposure to
the sun at near- perpendicular angles in the summer months during the
afternoon.
No good for winter heating of course, but air conditioning costs me
around $30.00 per month on average from mid-June to mid-September, even
in my one-bedroom apartment.
What _really_ did help out with the electrical bill was moving from
incandescent to fluorescent bubs for lighting in the apartment. I used
to use four 75 -100 watt incandescent bulbs to light the living room
alone; now I can crank up every bulb in the apartment and use around 200
watts total.
Given the long multi-year life of the fluorescent bulbs and their fairly
low cost per bulb now, and I'm way ahead on total costs.
At the moment, I'm using a total of 80 watts to light the living room
and another 10 watts to light the bathroom.

Pat

On Jun 10, 12:10*am, Pat Flannery wrote:
Totorkon wrote:

* *A house must have a large southern exposure, preferably
with a roof peaked at the proper angle. *Forget planting
shade trees.

Depends on the height of the house - even up here at around 45 degrees
north latitude, a two-storie house could provide reductions of cooling
costs in the summer when its roof pitch matches the maximum exposure to
the sun at *near- perpendicular angles in the summer months during the
afternoon.
No good for winter heating of course, but air conditioning costs me
around $30.00 per month on average from mid-June to mid-September, even
in my one-bedroom apartment.
What _really_ did help out with the electrical bill was moving from
incandescent to fluorescent bubs for lighting in the apartment. I used
to use four 75 -100 watt incandescent bulbs to light the living room
alone; now I can crank up every bulb in the apartment and use around 200
watts total.
Given the long multi-year life of the fluorescent bulbs and their fairly
low cost per bulb now, and I'm way ahead on total costs.
At the moment, I'm using a total of 80 watts to light the living room
and another 10 watts to light the bathroom.

Pat


Sometime in grade school I realized that spaceships
were more like submarines than say, skyscrapers.

Algae to fish, crawdads, chickens and goats would
be practical if the first step photosynthesis is
optimized in 'algae tubes'. Set in a spining cylinder
with a conical solar reflector insert. A small
amount of volume, at minimal pressure, with a high CO2
content. This would all be on different structure,
separated from the well shielded crew quarters, put at
the end of a 2000 ft tether (balanced against the
less shielded animal habitat).

We will need water, frozen food and the freezers
to keep it in. Add various other supplies. Why not
put your 0.16g bed inside this wall of survival
stuff and save yourself a lot of cosmic radiation.

Bottom line: there will be windows on transplanetary
journeys, but there won't be much to see, certainly
nothing to match looking up from earth to the starry
night.

Life onboard will look like life in your living
quarters at night...except it will be smaller.

And just plain forget going outside in your
shirtsleaves, or even your heaviest coat... ever.

Totorkon wrote:

Sometime in grade school I realized that spaceships
were more like submarines than say, skyscrapers.


Actually, that's _exactly_ what they are like, which makes _this_
concept fun:
http://davidszondy.com/future/space/dean_drive.htm
Note that in the movie "Robinson Crusoe On Mars" the Mars Gravity Probe
1 is crewed by two Navy officers.
Nuclear missile sub crews would make ideal candidates for a
interplanetary spacecraft crew, as they are already capable of
psychologically dealing with months at a time in a cramped space with no
windows, surrounded by a very hostile environment.


Pat