And the sustainable development/energy folks wonder why they can't get us to take them seriously.

Check out this bit of technological illiteracy in an FAQ on energy sources:

Why don't we build a solar plant on the moon and beam the energy back to Earth?

We don't do this for the same reason we don't cover North Dakota with wind turbines to supply the whole country with electricity; transmission costs. Disregarding the insanely expensive cost of building a solar plant on the moon, transmitting this energy back would be technically impossible. In addition, with the rotation of the moon and the earth as they are, the transmission cables would quickly become terribly tangled.

But wait--if they use "transmission lines," then it's not technically impossible, just difficult. Of course, it would only occur to idiots like this to use transmission lines, and of course the question said nothing about transmission lines--it asked about beaming power.

"Beaming" electricity is not quite the same as beaming Scotty up to the Enterprise.

True. Unlike beaming Scotty, it's actually been demonstrated, with 90% efficiency...

Electricity travels along transmission cables that are inefficient and very expensive: high voltage cables can cost thousands of dollars per mile. [42] If we could devise a way to efficiently "beam" electricity without transmission cables, we would be utilizing this technology first to connect earthbound power plants with various earthbound consumers.

Except for that nasty little line-of-sight problem...

They don't seem to have any concept of using the right tool for the job. Of course, where you can, you use transmission lines, because they're more efficient than beaming. But if you can't, then beaming may be good enough.

Perhaps a better idea would be to build solar plants on the earth and then just keep the energy here.

Except that the sun goes out at night, and it's diminished by clouds, and not all latitudes get decent sunlight, and...

The problem with terrestrial solar is the storage problem. It can't provide reliable 24/7 power, and it will always be a marginal, decentralized source until we can come up with cost-effective ways to store large amounts of energy.

It is true that the sunlight on the moon's surface can be more intense than on the earth's surface, due to its lack of atmosphere, but this greater intensity does not justify the R&D effort that would be required to pursue extra-terrestrial capture of solar energy for use on earth.

No, it doesn't. Of course "intensity" is not the reason that gathering power in space is potentially attractive, as the numbskull who wrote this would have learned from even a cursury glance at the abundant available literature.

The interesting features of space power are that it's available continuously, there's no weather to interfere with it, and you can get much higher effective power densities at the ground collector than with terrestrial solar.

Furthermore since most industrialized countries experience power losses of about 10% between the generating plant and the customer, which is only at most in the hundreds of kilometers, there is no way the energy would be still coursing through the transmission cables after the 384,400 kilometers it would have to travel from the moon to the earth. [43] [44]

Not just ignorance, but willful ignorance because, as I said, a quick google would have revealed how stupid a statement this is.

But these people live in their own little world, and when they hear about an idea, they don't bother to actually research it, or give it any serious thought or analysis (though it's not obvious in this case that whoever wrote this nonsense is even capable of it, either from an intelligence, or knowledge standpoint), because its politically incorrect. Unlimited power from space implies that we don't have to live in their little "sustainable" renewable gulag, that we don't have to give up our SUVs, that we don't have to start splitting our own wood.

There are serious critiques to be made of space-based power (particularly from the Moon), and I'm on the fence as to whether or not it's a viable future energy source, but this is simply pathetic.

"There are serious critiques to be made of space-based power (particularly from the Moon), and I'm on the fence as to whether or not it's a viable future energy source, but this is simply pathetic."

I'm not on the fence regarding it being "viable future energy source", but I don't think the way of getting there as commonly described by NASA paid studies has a chance in hell of working.
I think the ultimate payback will be power from space shipped to Earth. But don't we can start with this as the immediate goal. Rather we need to start with small steps which lead to this.
One step which can have a more immediate payback to terrestial use, could be NASA paiding for a project which demonstrates power transmission using microwave or laser over long distances- hundreds to thousands of miles. This could lead to application of cheap power on Earth being transmitted via space to location on Earth in which there is market willing to pay a higher price. This can be routinue operation, such as say power from Canada being shipped to LA. It could also possibly be for less permanent situations- like a black out. Or for some isolated construction site, Outdoor concert, or for warfare, or for some peak use which might be needed once a week or month or whatever. In order to do this, of course, you would need to know how much this system would cost, then you would need to compare this cost to what is currently being charged in existing market temporary power generator (total cost, plus could you get a higher price if you deliver more power and in a quickier time frame). Or in the case power from Canada to LA, what is the current cost of getting this power [could you bypass the grid, buy directly, than plug into the grid in LA]?

Do NOT forward this to Jerry Pournelle.

His head would explode.

Good grief, like Simberg said, you'd the idiots who wrote the FAQ would do a little research on the possibilities of transmitting energy to Earth from space. I've long been a proponent of space based solar power since it is the only renewable energy source which has the potential to supply every watt we need. And such a power source sure beats the hell out of cluttering every mountain top and sea shore with windmills or paving over vast areas of land with solar panels.

Don't forget that we have other uses for that sunshine on Earth. Agriculture and plant life in general needs a lot of sunshine too.

I'm a little confused by the previous anonymous statement. Does the writer seriously think that Solar Power Satellites could impede enough sunlight to affect agriculture?
Although, if anything, if we set up large enough mobile arrays we could use them to cool off the tops of hurricanes by denying them sunlight, thus weakening the most deadly storms. So yes, we could block sunlight from the ground, but only intentionally.
Another possibility I've seen suggested is a "conerider", a combination solar sail/solar panel straddling the shadow cone from the Earth. Its edges would be exposed to sunlight, providing a balance against the Earth's gravity, and in the process collecting electricity which can be transmitted to relay satellites.

About the only quibble I have is that I think the correct Latin plural is IGNORAMI. Not having ever attended Catholic schools, though, I could be wrong.

Tanstaafl, Jerry's head wouldn't explode. He'd just forward gbaikie's post to Larry Niven and next year we'd have 'The Ringworld Billiard Table' on bookstore shelves; a novel about the placing of a giant skrith plate in geosynchronous Earth orbit to make that Canadian energy beam do a proper bank shot on its way to L.A.

I'd get less annoyed by this sort of thing if people would realise that generally we don't have an energy problem, at least one that nuclear fission and fast breeders can't solve.

If people would get over their nuclear hang ups we could move to a nuclear/electric system - mybe hydrogen for cars but that's not needed for quite some time.

This post, coming after the "evil jewish death rays' post, show that the two groups in question have a lot in common in their thinking processes. The major one is that they have no undertstanding of how science and engineering works, having replaced them by wishful thinking.

(I took a look a their FAQ on geothermal, a subject I know something about, and it's full of all sorts of wishful thinking. By now they should know that geothermal is a mining operation, and is renewable the same way coal is renewable,although the time frame isn't quite as long. And it's not pollution free, either. They mention air pollution, but not the scaling of pipes from minerals coming out of solution due to lowered fluid temperatures. At some plants pipes have to be reamed out on a frequent basis. And they gloss over the destruction of whole ecosystems based on hot springs, which are destroyed in the process, and never mention the fact that the best places for geothermal power are protected by national parks. How can you talk about Western US geothermal without ever using the word "Yellowstone" in your FAQ? What a bunch of shills.)

G. O'Neil, in The High Frountier, wrote, microwave electricity back to earth. Reading this I Assumed that the technologh already existed to do this. What I understand from the article, is that eather the technology does not exist or it requires too big of a percentage of the eletricity generated in space to make it economical. ---If O'Neil is right and it takes a 7 mile radius of land on earth to prevent injury to people by the dispersal of the microwave beam. then that would cancel out the articles argument of "line of site power transmition on earth as opposed to power cables." ---This brings up another question? Sinberg please note! How much of the book The High Frounter is realistic/feasable?

I am surprised that nobody so far has mentioned the 28 day-night cycle of solar flux on Luna's surface being a problem. :) Actually, electricity currently is being stored. In the US, there is about 18,000 MW of pumped storage for the diurnal cycle. Water is pumped uphill at night, and let run down through turbines in the daytime. Short term demand changes are handled by "spinning reserve", which is generators not running at full torque. This is in addition to the plants that are throttled at night to match the demand curve. (The big fossil burning base load generators can't be deeply throttled) Electricity demand is about a factor of two greater during day than night, depending on season. (Summer is more cyclic than winter) Until ground based solar plants reach several thousand MW, there is no storage problem with terrestrial solar power. Ground based solar plants are not being built simply because they are not cost competitive. They're getting close; note the new 50 MW solar plant Solargenix is starting to build near Boulder, NV.

I have been reading about space for many years. Unfortunatly I have found very few people who share the same interest who I can discuss the subject with. Thus I am full of misconceptions about space. BUT I am very interested in learning. It might help me and other people if you re-posted old articles on pertenant subjects so that we can correct the misconceptions that we have.

I did not intend the previous post (the one ending in Boulder, NV) to be anonymous. The software seems to have dropped ny name. From Dan DeLong. BTW, there is lots of good info on this subject at www.eia.doe.gov.

I am surprised that nobody so far has mentioned the 28 day-night cycle of solar flux on Luna's surface being a problem.

Actually, many people have--just not in this particular thread. Criswell's response is to have collectors all over the surface, and move the power to the transmitting antennas via powerlines (perhaps of lunar aluminum).

Jim, Space Future has a treasure trove of information on this subject, as well as many others.

So, that came from an outfit called REPP? They must have mistyped the acronym. They wrote "Renewable Energy Policy Project". What they really meant was "Really Empty-headed Powerless Pinheads".

Of course, I could be mistaken. Perhaps some other readers can take a crack at deciphering what they really meant.

Jim Coomes,

"The highest record of 84% efficiency was attained
in the demonstration of microwave power transmission
in 1975 at the JPL Goldstone Facility. Power was
successfully transferred from the transmitting large
parabolic antenna dish to the distant rectenna site
over a distance of 1.6 km. The DC output was 30 kW."

(see http://www.kurasc.kyoto-u.ac.jp/plasma-group/sps/history2-e.html)

This is pretty bad, but doesn't even compare to the stupidity I ran into on a discussion board a couple of years ago where a colossal ignoramus calling himself Dsee was trying to promote the idea of capturing energy from lightning as a viable alternative source. The exchange was astounding.

Ave,

Nuclear power has the great advantage over
space-based solar power that we can do it
now instead of talking about doing it in
the future.

But skipping that it looks to me like
space-based solar power has advantages
over nuclear power. For one, long-term,
down in the fundamentals, it looks like
it's cheaper. (To reiterate, I mean after
one gets past the expensive original
development stage.) Space-based solar
power has this position, being fundamentally
less expensive, with respect to every
proposed and existing energy production
technology including oil except, just possibly,
fusion.

For another nuclear power carries the
hard-to-quantify risk of things like Chernobyl.
One might rejoin that Chernobyl was the
product of extraordinary incompetence, but
that's the point. If nuclear power plants
really do supply future needs they'd spread
everywhere and be run by people in some cases
with poor judgement. No similar risk attaches
to space-based solar power.

Mark,

For another nuclear power carries the
hard-to-quantify risk of things like Chernobyl.
One might rejoin that Chernobyl was the
product of extraordinary incompetence, but
that's the point.

I would say extraordinary incompetence AND extraordinarily bad engineering. To have a critical failure like that in a modern western reactor is pretty much impossible - apart from the neutron absorbing shut down systems and the second containment vessel, there's a bunch of other safety systems that make it impossible to even deliberately repeat that. Of course, there is still the "fear factor" of nuclear which is harder to quantify.

I remain agnostic on the true costs of space based power systems as, frankly, we haven't a clue. Nuclear is here and now and something we ought to be taking an example from the French.

Dave,

People have already imagined a number of different
kinds of space-based solar power plants and doubtless
there are a much larger number not yet conceived.
Thus what I'm about to speak of may not be the best
solution but it has the virtue in this context of
being easy to think about.

Imagine a large dish mirror that bounces the sunlight
it receives to a focus point which heats up a working
fluid that drives a turbine to generate power. Since
such a power plant is driven by a hot to cold differential
there has to be a radiator on the other side of the
mirror to cool down the working fluid.

We end up with two large static structures, the mirror
and the radiator, both of which are mostly metal, metals
which can be extracted from the moon or asteroids.
Almost all the complexity of such a power plant is down
near the focus and this is the only area ever likely
to need maintenance.

Oh, and we need also a microwave-transmitting array
to emit to a receiver which collects it and then
transmits to earth. Again, relatively static, low-maintenance
structures.

The materials required could be mined from the moon, thrown
into moon orbit and worked there into the form of power
plant and moved to where it's being used. Most of this
effort, perhaps all of it, can be automated.

Remember I'm ignoring the cost of learning how to do
all these things. What we end up with, what the real
baseline cost turns out to be, turns out to be a function
of how long such a plant can run on its own before it
breaks down and needs to be repaired.

Remember there are no environmental costs, the space to
deploy is trivial compared to the space available so there
is no real estate cost, and the masses involved are actually
pretty small, so the moon is barely touched, and the
opportunity cost low there.

Maybe the real cost turns out to be nothing that happens
in space but simply the energy distribution network from
the receiver on the surface of the earth.

There are many unknowns here. At best one can only
make ball park estimates, but sit down and think about
what is required to run an oil-fired power plant or
nuclear or solar cells on someone's roof -- the space-based
solar powered plant is going in the end to be cheaper.

Mark,

I'm not arguing that an SPS is complex, far from it. The basic mirror/heater type array is mechanically simple.

Where my problems lie are in the statement "Remember I'm ignoring the cost of learning how to do all these things."

I suggest you start drawing a simple Gant chart of the items you need and when you'd need them. Take the construction of a similar sized structure on Earth but assume that the production infrastructure also has to be assembled first. Also, don't ignore that many of these things have not yet been attempted and while we have theorectical concepts of how to mine and smelt lunar materials we have not done so. Nor have we build linear accelerators or coil guns on the scale needed to get lunar materials to Earth orbit.

Given we have no orbital or lunar infrastructure and that cost should not and cannot be excluded from the equation, I don't see the sums adding up even with a 3 or 4 order of magnitude drop in launch costs.

So considering this statement, "sit down and think about what is required to run an oil-fired power plant or nuclear or solar cells on someone's roof -- the space-based solar powered plant is going in the end to be cheaper.
"...

I'm sorry, I don't really think it is. Certainly not at the moment, and even when we have the infrastructure you discuss I'm not convinced it will be cheaper then.

This is bad, but bad information on technology is common. How often have you read ?Nuclear waste will remain radioactive for (insert some number between 10,000 and 250,000 here) years??

Virtually everything is radioactive. The potassium that you need to live will still be (naturally) radioactive after the sun dies. The typical story about nuclear waste is worse than useless. Honest comparisons of the safety and practicality of various power sources are rare.

There?s no doubt solar power from space is technically feasible, but I?ve always questioned the economics. I?m pro-space, but it?s hard to understand how a giant space solar array running at 15-40% feeding a giant space microwave transmitter beaming to a giant ground rectenna at 70-85% generating DC to be converted to AC at 90% could compete against Earth based power sources. Don?t forget that the space based hardware has to handle substantial radiation, and is just a bit more expensive/harder to build than Earth based hardware (even WITHOUT Nasa). And there are folks ALREADY worried about the low-density microwave energy, so good luck building the rectennas.

If somebody came up with a self replicating robot system, it might make sense, or when space gets a lot cheaper. But I think we?ll do a lot of other things in space before this becomes a serious possibility.