History's Worst Presidential Candidate

On Wed, 27 Oct 2004 11:34:04 -0700, Hop David
wrote:

I wonder how much surface area could be used if everyone's roof was
covered with photovolaics.
Hey, there'd be a lot less line loss!

Living in a condo/apartment complex, I don't have a lot of surface
area on the roof to cover. And spreading the power we *would* collect
between 184 residences wouldn't save much... :-)

Alex Terrell wrote:

Besides, once the first operational SSPS is built, it won't be long
before they can supply all of Earth's energy needs. (And the person
who builds the first could well have a monopoly on the whole thing).

I hope not. Then they'd have more power than the water empires (where
the emperor controlled irrigation).

Concentration of power is dangerous. I would hope several entities will
provide SSPS.

--
Hop David
http://clowder.net/hop/index.html

"Hop David" wrote in message
...

Alex Terrell wrote:

Besides, once the first operational SSPS is built, it won't be long
before they can supply all of Earth's energy needs. (And the person
who builds the first could well have a monopoly on the whole thing).

I hope not. Then they'd have more power than the water empires (where
the emperor controlled irrigation).

The Sun Cartel!

--


Regards,
Mike Combs
----------------------------------------------------------------------
Member of the National Non-sequitur Society. We may not make
much sense, but we do like pizza.

"Alex Terrell" wrote in message
om...

If Bill Gates builds a SSPS, he's not going to position it over (south
of) Seattle just becaue that's his state. same if Mitsubishi puts the
first one up. They'll do a massive analysis to see where the most
profitable market is, and serve that market. Some points:

- Electricity prices in the developed world are not necessarily higher
than in the developing world.
- Europe has good inter connection grids, so one rectanna can serve a
huge number of people
- USA is further south than Europe, and has cheaper land, so rectannas
will be cheaper
- North America has seasonal demand in the South (hot summers) which
will be opposite to the seasonal demand in the North (cold winters)
- Areas of fast economic growth are more likley to have demand
outstrip supply.

nice analysis

Besides, once the first operational SSPS is built, it won't be long
before they can supply all of Earth's energy needs.

sorry, that's completely wrong.

do the math: a single SPS, even based on the latest ultralightweight
designs, would require thousands of launches to get everything uphill and
assembled (weight isn't the only consideration, there's the simply matter of
*volume*). That's just for a single SPS, which would generate less than 1%
of the domestic power comsumption in the US, at roughly twice the cost per
kWH as a conventional terrestrial plant.

We've been over this ad nauseum befo unless we somehow develop a cheap,
dependable, airline-type method of getting stuff into orbit (or a cheap,
dependable, airline-type method of mining lunar ores, take your pick) then
SPS is simply unworkable and uneconomical in the extreme.

Like it or not, we're gonna have to solve our energy problems ritecheer on
Earth for the forseeable future.

--
Terrell Miller


" A strong conviction that something must be done is the parent of many
bad measures."
-- Daniel Webster

Terrell Miller wrote:
"Alex Terrell" wrote in message
om...
Besides, once the first operational SSPS is built, it won't be long
before they can supply all of Earth's energy needs.

sorry, that's completely wrong.

do the math: a single SPS, even based on the latest ultralightweight
designs, would require thousands of launches to get everything uphill and
assembled (weight isn't the only consideration, there's the simply matter of
*volume*). That's just for a single SPS, which would generate less than 1%
of the domestic power comsumption in the US, at roughly twice the cost per
kWH as a conventional terrestrial plant.

Current energy usage world-wide runs at around 400 EtaJoules
per year, or an average of roughly 13 teraWatts continuously.
Even at 100% conversion efficiency of the ~1400 W/m^2 of
insolation at Earth this corresponds to over 9,000 km^2 of
area in solar power systems. This is a lower bound, a more
realistic estimate would be at least a factor of 4 larger
due to inefficiencies in each step of the process. Even
very low estimates of the mass of SPS systems and of the
launch costs yield values of tens of thousands of tonnes of
material put into orbit at a cost of hundreds of billions
of dollars.

This ain't gonna happen overnight.


We've been over this ad nauseum befo unless we somehow develop a cheap,
dependable, airline-type method of getting stuff into orbit (or a cheap,
dependable, airline-type method of mining lunar ores, take your pick) then
SPS is simply unworkable and uneconomical in the extreme.

Like it or not, we're gonna have to solve our energy problems ritecheer on
Earth for the forseeable future.

"Christopher M. Jones" wrote in message ...
Terrell Miller wrote:
"Alex Terrell" wrote in message
om...
Besides, once the first operational SSPS is built, it won't be long
before they can supply all of Earth's energy needs.

sorry, that's completely wrong.

do the math: a single SPS, even based on the latest ultralightweight
designs, would require thousands of launches to get everything uphill and
assembled (weight isn't the only consideration, there's the simply matter of
*volume*). That's just for a single SPS, which would generate less than 1%
of the domestic power comsumption in the US, at roughly twice the cost per
kWH as a conventional terrestrial plant.

Current energy usage world-wide runs at around 400 EtaJoules
per year, or an average of roughly 13 teraWatts continuously.
Even at 100% conversion efficiency of the ~1400 W/m^2 of
insolation at Earth this corresponds to over 9,000 km^2 of
area in solar power systems. This is a lower bound, a more
realistic estimate would be at least a factor of 4 larger
due to inefficiencies in each step of the process. Even
very low estimates of the mass of SPS systems and of the
launch costs yield values of tens of thousands of tonnes of
material put into orbit at a cost of hundreds of billions
of dollars.

Key phrase: "Put into orbit"

Significant SPS will not happen if we need to put mass into orbit
(from Earth surface).

If however we use NEO (or lunar) resource, there is no reason why the
mass increase should not be exponential.

500,000km2 a few decades after launch is quite feasible. The total
mass is half that of a single O'Niell cylinder.

Alex Terrell wrote:
Key phrase: "Put into orbit"

Where, pray tell, do you intend to put an SPS other than
in Earth orbit? Notice that I did not say from where.


Significant SPS will not happen if we need to put mass into orbit
(from Earth surface).

If however we use NEO (or lunar) resource, there is no reason why the
mass increase should not be exponential.

And the cost? It seems unlikely that manufacturing
operations, of SPS hardware or of launch systems, will
be anything other than extraordinarily more expensive
than on Earth. The key advantage of NEO resource
utilization is that the delta V from there to Earth
orbit is much lower than from Earth to Earth orbit.
At best this works out to much less than an order of
magnitude decrease in launch vehicle size, and a
reduction of stages down to, perhaps, one. This may
be enough to compensate for the increase in cost due
to extraterrestrial operations, but that seems
unlikely.


500,000km2 a few decades after launch is quite feasible. The total
mass is half that of a single O'Niell cylinder.

And the cost?

"Christopher M. Jones" wrote in message ...
Alex Terrell wrote:
Key phrase: "Put into orbit"

Where, pray tell, do you intend to put an SPS other than
in Earth orbit? Notice that I did not say from where.

You do imply later that it's launch from surface.


Significant SPS will not happen if we need to put mass into orbit
(from Earth surface).

If however we use NEO (or lunar) resource, there is no reason why the
mass increase should not be exponential.

And the cost? It seems unlikely that manufacturing
operations, of SPS hardware or of launch systems, will
be anything other than extraordinarily more expensive
than on Earth. The key advantage of NEO resource
utilization is that the delta V from there to Earth
orbit is much lower than from Earth to Earth orbit.
At best this works out to much less than an order of
magnitude decrease in launch vehicle size, and a
reduction of stages down to, perhaps, one. This may
be enough to compensate for the increase in cost due
to extraterrestrial operations, but that seems
unlikely.

Which is why SPS is only a viable proposition with a significantly
greater orbital capability than we have now. Given that, delta-V from
an NEO to GEO is about 2km/s. Assuming exhaust velocity of 40km/s,
mass fraction is about 95%, and all is reusable.

For an Eath launch to GEO, virtually nothing is reused and the mass
fraction is about 1%.


500,000km2 a few decades after launch is quite feasible. The total
mass is half that of a single O'Niell cylinder.

And the cost?

Much less than $50 trillion, including the orbital infrastructure,
space colonies, and 50 TW of supply.

"Christopher M. Jones" wrote in message ...
Terrell Miller wrote:
"Alex Terrell" wrote in message
om...
Besides, once the first operational SSPS is built, it won't be long
before they can supply all of Earth's energy needs.

sorry, that's completely wrong.

do the math: a single SPS, even based on the latest ultralightweight
designs, would require thousands of launches to get everything uphill and
assembled (weight isn't the only consideration, there's the simply matter of
*volume*). That's just for a single SPS, which would generate less than 1%
of the domestic power comsumption in the US, at roughly twice the cost per
kWH as a conventional terrestrial plant.

Current energy usage world-wide runs at around 400 EtaJoules
per year, or an average of roughly 13 teraWatts continuously.

Even at 100% conversion efficiency of the ~1400 W/m^2 of
insolation at Earth this corresponds to over 9,000 km^2 of
area in solar power systems. This is a lower bound, a more
realistic estimate would be at least a factor of 4 larger
due to inefficiencies in each step of the process.

So, using a factor of 4, we need 36,000 km^2 of solar panels or of
mirrors reflecting into heat engines. By an amazing coincidence, this
is almost exactly the amount of aluminum foil made in Europe in 2003.
So if we can make 4% as much as that in space (as well as heat engine
parts, microwave components, etc) using lunar materials, then in 25
years we could provide all the Earth's current energy needs.

Even very low estimates of the mass of SPS systems and of the
launch costs yield values of tens of thousands of tonnes of
material put into orbit at a cost of hundreds of billions
of dollars.

"hundred billion dollars" / "ten thousand tonnes" = $10,000/kg
You consider this to be a "very low estimate of launch costs"? Good
grief, how would you launch the materials, on the Shuttle? Any person
seriously considering SPS on a large scale assumes the use of lunar or
asteroidal material, with much lower launch costs.

This ain't gonna happen overnight.

True. What source of power would?

We've been over this ad nauseum befo unless we somehow develop a cheap,
dependable, airline-type method of getting stuff into orbit (or a cheap,
dependable, airline-type method of mining lunar ores, take your pick) then
SPS is simply unworkable and uneconomical in the extreme.

I'm not sure how airlines do mining but many proposals for SPS (see
Gerard O'Neill's) assume using electromagnetic "catapults" (mass
drivers) on the Moon to launch the raw materials to orbiting
factories. Lunar launch requires less than 5% the energy of Earth
launch, no vehicles, and no propellant.

Like it or not, we're gonna have to solve our energy problems ritecheer on
Earth for the forseeable future.

What do you propose?

"Bill Bogen" wrote in message
om...

Even very low estimates of the mass of SPS systems and of the
launch costs yield values of tens of thousands of tonnes of
material put into orbit at a cost of hundreds of billions
of dollars.

"hundred billion dollars" / "ten thousand tonnes" = $10,000/kg
You consider this to be a "very low estimate of launch costs"? Good
grief, how would you launch the materials, on the Shuttle? Any person
seriously considering SPS on a large scale assumes the use of lunar or
asteroidal material, with much lower launch costs.

now you just have to pay for all the lunar/asteroidal mining infrastructure,
and amortize that over the life of the SPS(s)...

We've been over this ad nauseum befo unless we somehow develop a
cheap,
dependable, airline-type method of getting stuff into orbit (or a
cheap,
dependable, airline-type method of mining lunar ores, take your pick)
then
SPS is simply unworkable and uneconomical in the extreme.

I'm not sure how airlines do mining

funny man

but many proposals for SPS (see
Gerard O'Neill's) assume using electromagnetic "catapults" (mass
drivers) on the Moon to launch the raw materials to orbiting
factories. Lunar launch requires less than 5% the energy of Earth
launch, no vehicles, and no propellant.

be sure to factor in the development costs of the electromagnetic catapults,
as well as all the other infrastructure stuff.

Like it or not, we're gonna have to solve our energy problems ritecheer
on
Earth for the forseeable future.

What do you propose?

short-term: media blitzes for energy-efficient purchases and consumer habits
(grade-school stuff like "don't leave all the lights on", "turn the
thermostat up in the summer and down in the winter", "carpool and combine
trips", "don't buy an SUV": stuff that adults should do without thought but
don't); aggressive promotion of hybrid gas-electric engine technology;
Zarqawi whoever the ****er was who brought back the Hemi; aggressive
marketing of energy-efficient appliances and home fixtures; increased
research funding for alternative energy technology.

Not a panacea, but enough to at least tread water and not use any more
energy than we already do.

Long-term: all the space-based infrastructure development you mentioned.
You're on the right track, but getting there isn't anything that you can
glibly assume, and there are bound to be lots of "gotchas" that we don't
realize today that may very well make the entire SPS concept never feasible
nomatter how much it's developed.

--
Terrell Miller


" A strong conviction that something must be done is the parent of many
bad measures."
-- Daniel Webster