What would you like to be our major goals in space

Paul F. Dietz wrote:
Alex Terrell wrote:

IF it becomes competitive with other sources of electricity, becoming
cheap enough to displace fossil fuels could for heat and locomotion
would be quite feasible. I would expect SSP to have very low marginal
costs.

It would have to be much cheaper than current electricty in order
to compete for many heating applications.

Electricity is already used in much of the world for heating,
especially where you have a large base load, low cost power source,
like nuclear in France. note also heating can be done with heat pumps,
rather than resistors.

And why do you expect SSP to have a low marginal cost? The cost
of adding another powersat will not be cheap.

Because construction in space has fairly low dis-economies of scale. If
I build a "printer" to print solar sheets on to a substrate, I might as
well make the "printer" 1 km wide and print my sheets 10km long (based
on automated beam builders). Once I have a lunar catapult, the marginal
cost of mass in orbit is tiny. On Earth, the costs of transport and the
weaknesses of materials provide big diseconomies of scale to a lot of
construction projects.

Do you mean low
*operating* cost? That may be true, but it's not at all important
in the context of the issue being discussed. Nuclear also has
very low operating costs. It's a shame the people lending
the money to build the things expect to be repaid, with interest.

More importantly, its a safer bet to spend $150 million building a gas
plant instead of 1.5bn building a nuclear plant. If gas is too
expensive, my $150 million plant was a waste of money. If gas is too
cheap, the $1.5 bn nuclear plant was a waste of money. Likewise,
starting from today, SSP is not viable. Starting from an active moon
base with CATS, that might not be the case. The private sector on its
own won't make SSP happen.

But back to global warming: the big advantage of sunshades is that
they work even in the face of defection. In contrast, if there's
substantial resistance to the prohibition to exploit fossil fuels
(and in the long term, emission rates will have to be reduced 90% or more
to halt CO2 buildup). then global warming will happen, just more
slowly than otherwise.

You may be right. If SSP makes an impact, oil prices will fall to $5
per barrel even if demand drops only 30%. Active climate control though
is an unknown science, but it might be necessary.

Bear in mind some active climate control technologies use the same
infrastructure basis as SSP.

Alex Terrell wrote:

Electricity is already used in much of the world for heating,
especially where you have a large base load, low cost power source,
like nuclear in France. note also heating can be done with heat pumps,
rather than resistors.

Electricity is usually noncompetitive for heating. There can be
local exceptions, but the general rule is that burning fossil
fuels is cheaper. Heck, burning *biomass* is often cheaper.

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.

And why do you expect SSP to have a low marginal cost? The cost
of adding another powersat will not be cheap.

Because construction in space has fairly low dis-economies of scale.

It remains completely undemonstrated (handwaving notwithstanding)
that SSP can be economical at *any* scale. The distance from here
to there is just too large to say such a thing with non-zero confidence.
Just about any of the myriad of alternative energy sources here on
earth is far closer to practicality.


You may be right. If SSP makes an impact, oil prices will fall to $5
per barrel even if demand drops only 30%.

The $5/barrel figure appears to have been pulled out of an orifice.
Please justify. I find it completely unbelievable.

Paul

On Sat, 09 Dec 2006 09:11:47 -0600, in a place far, far away, "Paul F.
Dietz" made the phosphor on my monitor glow in such a
way as to indicate that:

Electricity is usually noncompetitive for heating. There can be
local exceptions, but the general rule is that burning fossil
fuels is cheaper. Heck, burning *biomass* is often cheaper.

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.

Yup. Welcome to south Florida.

Which sucks, because it means that I can't have a gas stove, unless I
want to a tank in the yard. There's zero gas infrastructure here,
other than delivery.

Paul F. Dietz wrote:
Alex Terrell wrote:

Electricity is already used in much of the world for heating,
especially where you have a large base load, low cost power source,
like nuclear in France. note also heating can be done with heat pumps,
rather than resistors.

Electricity is usually noncompetitive for heating. There can be
local exceptions, but the general rule is that burning fossil
fuels is cheaper. Heck, burning *biomass* is often cheaper.

That depends on the prices of fossil fuels and electricity. There is a
good chance that fossil fuels will be a lot more expensive a few
decades from now. That said, if you have abundant cheap electricity, it
makes sense to go for the easier markets of electricity and
transportation, before domestic heating.

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.

If you have AC, makes sense to use it in the winter. Is AC is pretty
much standard across the US?

And why do you expect SSP to have a low marginal cost? The cost
of adding another powersat will not be cheap.

Because construction in space has fairly low dis-economies of scale.

It remains completely undemonstrated (handwaving notwithstanding)
that SSP can be economical at *any* scale. The distance from here
to there is just too large to say such a thing with non-zero confidence.
Just about any of the myriad of alternative energy sources here on
earth is far closer to practicality.

I did say IF, and I would expect the marginal cost to be low. If you
disagree with that, you're not even handwaving, since you haven't
raised any counter point.

As for the myriad energy sources, there are a couple which might be
closer to practicality (for multi TW production). I wouldn't want to
bet on anyone in particular.


You may be right. If SSP makes an impact, oil prices will fall to $5
per barrel even if demand drops only 30%.

The $5/barrel figure appears to have been pulled out of an orifice.
Please justify. I find it completely unbelievable.

The orifice in question is a Saudi oil well. And it doesn't need
pulling. Bring the price of an alternative down to $5/barrel, and
people will still keep on pumping at this level.

That said, there may not be any Saudi oil in a few decades. The peak
oil debate seems highly inconclusive.

Alex Terrell wrote:

That depends on the prices of fossil fuels and electricity.

Yes. The ground rules in space fan discussions of SSP is that
it is assumed to be extremely cheap. Maybe even too cheap to meter
(cheap shot).

There is a
good chance that fossil fuels will be a lot more expensive a few
decades from now.

Only if they run out. CO2 sequestration will not add enormously
to the cost of fossil fuels.


That said, if you have abundant cheap electricity, it
makes sense to go for the easier markets of electricity and
transportation, before domestic heating.

If we had some ham, we could make ham and eggs, if we had some eggs.

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.


If you have AC, makes sense to use it in the winter.

Not really. If it gets too cold outside, the performance
of the heat pump goes all to hell, and you have to go back
to resistive heat. Do this enough, and you save with a gas
heater, in which case you don't really buy anything by having
the more expensive dual mode A/C.

Is AC is pretty much standard across the US?

Single mode is very common. Dual mode (doubling as a heat
pump) is not nearly as common. In cold areas heat pumps don't
cut it, unless you go to ground source heat pumps, but those
are very expensive to install ( $10K in many cases).


I did say IF, and I would expect the marginal cost to be low. If you
disagree with that, you're not even handwaving, since you haven't
raised any counter point.

I reject this part of your argument as well. You'd expect the cost
of subsequent units to be *lower* than the first, but this doesn't
mean the cost would be low in an absolute sense.

You may be right. If SSP makes an impact, oil prices will fall to $5
per barrel even if demand drops only 30%.

The $5/barrel figure appears to have been pulled out of an orifice.
Please justify. I find it completely unbelievable.


The orifice in question is a Saudi oil well. And it doesn't need
pulling. Bring the price of an alternative down to $5/barrel, and
people will still keep on pumping at this level.

That said, there may not be any Saudi oil in a few decades. The peak
oil debate seems highly inconclusive.

SSP will not be available anytime soon. I would be utterly amazed if
it were available even in pilot form in my lifetime.

When it does come online, it will not suddenly displace 30% of oil
consumption, so your suddent oil price crash scenario makes little sense.
I would also be amazed if it had significant effect that
existing terrestrial electricity sources had not already had.

Paul

In article ,
Paul F. Dietz wrote:
Alex Terrell wrote:

There is a
good chance that fossil fuels will be a lot more expensive a few
decades from now.

Only if they run out. CO2 sequestration will not add enormously
to the cost of fossil fuels.

And with the amount of coal in the ground, we shouldn't
run out before the 22nd century.


--
http://www.cic.gc.ca/english/immigrate/
http://www.livejournal.com/users/james_nicoll
http://www.cafepress.com/jdnicoll (For all your "The problem with
defending the English language [...]" T-shirt, cup and tote-bag needs)

"Paul F. Dietz" wrote in message
...
Alex Terrell wrote:

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.


erm, that doesn't sound right. If they have high capital costs, you'd want
to use them in places where they will be run for long stretches of the year,
to amortize the initial cost. Alaska. You would *not* want to use them in
South Florida, since you only need to run the heater for a few months of the
year, and only during teh evening for the most part.

The limiting factor isn't the capital cost, it's efficiency. We've got a
heat pump in our cottage up in the Blue Ridge mountains, and it doesn't work
worth a damn. We have to burn firewood and use space heaters in the
bedrooms.

The rule of thumb I've heard is that anywhere with a latitude higher than
~33 degrees (i.e. anything north of Gibraltar, Baghdad, Shanghai, Nagasaki,
Atlanta, Dallas, Phoenix and LA, or south of Sydney, Cape Town and Buenos
Aires) isn't suitable for heat-pump use. That leaves out a good chunk of the
world's population, a lot of folks who live too far away from teh equator
for heat pumps to be efficient, and a lot more that live so close to teh
equator that they don't often need a heat pump in the first place.


--
Terrell Miller


"Just...take...the...****ing...flower...darlin g"
Terrell's dating style according to OKCupid.com

"Terrell Miller" wrote:

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.

erm, that doesn't sound right. If they have high capital costs, you'd want
to use them in places where they will be run for long stretches of the year,
to amortize the initial cost. Alaska. You would *not* want to use them in
South Florida, since you only need to run the heater for a few months of the
year, and only during teh evening for the most part.

I think you misunderstood something. Typical homes in South Florida
*already* have a heat pump that they use much of the year. It's called
an air conditioner. The idea is that you spend a little bit more to
make it usable in reverse and pump heat *into* the home instead of out
of it. The fact that you don't need very much heat for very long is an
argument in favor of doing it that way.

The limiting factor isn't the capital cost, it's efficiency. We've got a
heat pump in our cottage up in the Blue Ridge mountains, and it doesn't work
worth a damn. We have to burn firewood and use space heaters in the
bedrooms.

An air-to-air heat pump can't pull much heat out of very cold air. I
suppose "efficiency" is a reasonable term to use for it.

The rule of thumb I've heard is that anywhere with a latitude higher than
~33 degrees (i.e. anything north of Gibraltar, Baghdad, Shanghai, Nagasaki,
Atlanta, Dallas, Phoenix and LA, or south of Sydney, Cape Town and Buenos
Aires) isn't suitable for heat-pump use.

Places where the air gets significantly below freezing are not suitable
for *air-to-air* heat pump use. They're perfectly fine for
water-sourced or geothermal heat pumps. The problem is that such
systems have a very large up-front cost, so the lower operating cost
doesn't give a net benefit until after a very long time.

That leaves out a good chunk of the
world's population, a lot of folks who live too far away from teh equator
for heat pumps to be efficient, and a lot more that live so close to teh
equator that they don't often need a heat pump in the first place.

A lot of places close to the equator *do* use heat pumps for cooling.

On Sun, 10 Dec 2006 12:26:30 -0500, in a place far, far away, "Terrell
Miller" made the phosphor on my monitor glow
in such a way as to indicate that:

"Paul F. Dietz" wrote in message
...
Alex Terrell wrote:

Heat pumps have high capital cost, which offsets much of the
economic gain from the efficiency improvement. You usually
see them in places where so little heating is required you
just make the A/C dual purpose.


erm, that doesn't sound right. If they have high capital costs, you'd want
to use them in places where they will be run for long stretches of the year,
to amortize the initial cost. Alaska. You would *not* want to use them in
South Florida, since you only need to run the heater for a few months of the
year, and only during teh evening for the most part.

Yes, sorry. In fact, we don't have a heat pump. We have an A/C with
a heater element for cold days. Though we're thinking about getting a
heat pump for the pool.

"Alex Terrell" wrote:

:
:Or perhaps more optimistically, the future of batteries. Even if
:batteries don't progress significantly from current status, they're
:still good enough (if not yet cheap enough) to make Plug in Hybrids a
:winner. With 100km range, that would pretty much halve fossil fuel
:consumption in the USA. More than halve it in Europe.

With 100 km range, they barely get a lot of us to work and back each
day. Why the hell would I want to pay a premium for something that
limited?

--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn