PG&E Makes Deal For Solar Power From Space 392
N!NJA writes "California's biggest energy utility announced a deal Monday to purchase 200 megawatts of electricity from a startup company that plans to beam the power down to Earth from outer space, beginning in 2016. Solaren would generate the power using solar panels in Earth orbit and convert it to radio-frequency transmissions that would be beamed down to a receiving station in Fresno, PG&E said. From there, the energy would be converted into electricity and fed into PG&E's power grid."
Bad idea (Score:2, Insightful)
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Re:Bad idea (Score:4, Interesting)
This is a horrible idea. What happens when the beamer is hit by a micro meteor nocking out the com and pointing the sat at SF?
Forget micrometeors. The real question is: what happens when Solaren goes the Enron way (and isn't bailed out by your tax dollar) and their satellite is allowed to go derelict and drift? Will it leave a narrow trail of roasted humans across California?
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Will it leave a narrow trail of roasted humans across California?
No. The microwaves are the wrong frequency, they don't interact with water and will pass straight through any living creature.
So what frequency are they? All I have to say, (Score:3, Funny)
is somebody better run this by the HAM radio operators.
They say that hell hath no fury like a woman scorned, but that saying came into being before HAMs were on the scene.
Re:Bad idea (Score:4, Informative)
Again, no. The microwaves don't interact with organic matter, they pass through. You're not getting cancer from TV broadcasts or mobile phone towers either.
Re:Bad idea (Score:4, Insightful)
Why don't you stand in front of a 200 Megawatt transmission and get back to us on that one?
Re:Bad idea (Score:5, Interesting)
Everyone does that every day. It's called the sun. That's where this thing gets its energy from. However, there is a key difference between solar radiation, and the radiation that this machine produces. The reason that we have solar frequencies converted to this frequency, is because it interacts close to nothing with the atmosphere, or just about any organic particle/interference. A lot of matter interacts with very specific frequencies, which is why this frequency will only give power to the designated material. Think of an atom as a football at the center of the stadium. The electrons would be like flies in the bleachers. Now if you want to hit the flies with bullets, you have to aim to where they generally are, or you'll miss. It works kinda like that.
Re:Bad idea (Score:4, Insightful)
I *GAVE* them a damned idea that would save MILLIONS and cost very little to implement. I even did the research myself. And THIS is what they're getting? My idea would've generated ten times the amount of power, at FAR LESS COST.
Then publish your research and promote it.
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Let me see if I understand you. You had a million dollar idea, invested your time in the research necessary to demonstrate its viability, and then you *GAVE* it away for free. And the people you gave it to are the morons?
Can I have your next million dollar idea?
Re:Bad idea (Score:4, Informative)
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You answered your own question. It cant produce a narrow beam, which is the same reason why it cant cook anybody. You have a large diameter beam (kilometers in diameter) at a low power density (similar to the energy density of sunlight) and a huge rectenna array (say, covering many farmers fields by being upheld on stilts). Yes, this works. I have studied it. Smarter people than you or I have studied it. I swear to god NOBODY on slashdot understands power density. Every frikin time this subject comes up its
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Then I recommend MythBuster's Free Energy episode, where they did pull a tiny bit of electricity out of the air from radio waves.
In general terms, it's how a crystal radio gets the power to run. You didn't think the 100 or 300 or how ever many watts the radio stations brag about broadcasting just vaporised?
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You are aware that there are different frequencies of microwaves yes? Some that do agitate water (and heat it up) and others that don't. As long as the power satellite uses one of the frequencies that don't, then yes I'd happily spend an indefinite amount of time in its path.
Just like I'll consume as much plutonium as you're willing to consume caffeine.
Re:Bad idea (Score:4, Interesting)
I was referring to this:
http://www.atomicinsights.com/may95/plutonium_eff.html [atomicinsights.com]
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What happens when the beamer is hit by a micro meteor nocking out the com and pointing the sat at SF?
Then San Francisco residents finally get to be warm [igougo.com].
Re:Bad idea (Score:5, Funny)
Re:Bad idea (Score:5, Funny)
The effects of microwave radiation on high density airborne smug are still unknown
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I take it you never heard of the concept of "failsafe" systems? For instance - the ground station is transmitting a "keep alive" signal to the satellite once every 100ms. The satellite hardware is designed so that if the keep-alive isn't received after 250ms, it automatically cuts off the transmitter.
And the ground station is set so that if it detects the power beam moving over a certain distance off-center of the receiver, it cuts the keep-alive.
The only part of this concept that's "rocket science" is th
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Considering how far the beam might deviate in 250 ms, I think the reaction time should be made much, much short. Microseconds.
Re:Bad idea (Score:4, Interesting)
Considering how far the beam might deviate in 250 ms, I think the reaction time should be made much, much short. Microseconds.
True - the reaction time should be shorter. So try this: The ground station is transmitting a laser signal, which the satellite receives using a system with a VERY limited field of vision. If the signal is interrupted, the power cuts off. That way if the satellite's orientation is disturbed enough to miss the receiver, it won't be able to see the laser...
The keep-alive idea I originally posted doesn't hold up on closer inspection - there's over 100ms of latency in a radio link from the Earth's surface to geosynchronous orbit...
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The problem is that a laser beam doesn't go any faster than light speed, either.
The satellite would have to determine on its own whether it's still pointing the right way.
Re:Bad idea (Score:5, Insightful)
The problem is that a laser beam doesn't go any faster than light speed, either.
The satellite would have to determine on its own whether it's still pointing the right way.
That's why I specified that the *receiver* have a very limited field of vision. If the satellite rotates enough to be off target, it can no longer see the laser. Thus no latency issues.
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Oh ... right. My bad. That should work as intended.
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The transmitting antenna of the system will presumably be a phased array which among other things can detect direction and strength of incoming signals. Sample the transmitting antennas at the same point in the wave each time (the aiming signal will be broadcast at a multiple of the power wave) and you don't even need any separate system. I would propose to do it with an analog system on sapphire insulator or similar, with redundant systems... not with a microprocessor. Hence you get your 'failsafe' aspect.
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Ummm The receiver is on the ground. You know, so it can receive the power from the sat.
The sat. is shooting out the laser beam from orbit to ground.
So... if the sat rotates enough to be off target, then the ground based receiver can no longer see the laser, not the satellite like you said. Which still leaves the issue of, how do you tell the laser it's pointing wrong, fast enough to prevent it from messing other stuff up?
The only solution is to use some type of GPS system with a very fine precision, so the satellite can calculate its actual orientation instantly.
The laser would also need to be mounted on some type of gyroscopic stabalizer, so that if the sat's orientation changes suddenly the laser will get blocked until the power can cut off.
I messed up with the word "receiver" on that one. Let me rephrase:
Have a sensor on the satellite with a very limited field of view, and a laser (or maser, or maybe just a plain microwave beam) sent from the ground station to the satellite. If the satellite's orientation changes enough to cause it to miss the target, the sensor would no longer "see" the signal from the ground station, and trigger a shutdown of the power beam.
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Apart from bugs in the satellite's software, there is a lot that can go wrong. But it would be a nice test case for anti-satellite warfare ;)
We *can* create systems that are bug immune. Note that I didn't say "bug free" - take three different architectures, and have three different teams write the code for them. Connect them in a "majority rules" redundant configuration. The odds of two of them experiencing bugs at the same time (or of having a hardware failure) producing the same result at the same time is pretty, well, astronomical...
Then there's the option of using completely dissimilar systems. For example, have the laser concept from my
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Note that I didn't say "bug free" - take three different architectures, and have three different teams write the code for them. Connect them in a "majority rules" redundant configuration. The odds of two of them experiencing bugs at the same time (or of having a hardware failure) producing the same result at the same time is pretty, well, astronomical...
Boeing tested this hypothesis -- it's called N-Version Programming -- and it doesn't work as nicely as we'd like. If you assume that the distribution of bugs is evenly random then yes, it's a great idea. But bugs don't do that, they tend to be clustered in particular modules and sections of code.
Boeing's study showed that multiple teams tended to have bugs in the same, complex areas. It was more cost-effective to do one implementation and spend more on it -- formal inspections, formal method proofs etc -- t
Mr. Freeze (Score:3, Funny)
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They solve the population problem?
As long as you have good fire coverage you should (Score:2)
As long as you have good fire coverage you should be able to put the fires out fast with little damage.
Interlock (Score:5, Informative)
These beaming systems have interlocks pointed back from the ground receiver to the satellite. If the two get out of alignment, the satellite immediately loses the ground signal, and immediately stops transmitting.
Besides, the beamed power density doesn't have to be very high per square meter. If it's just concentrated 5x from its density in space, it's 6.5KW:m^2. At this system's 2MW transmission rate, is only 308m^2, or a square 17.5m on a side. If it's really RF, even if the interlock failsafe failed, the beam wouldn't do much except fry some unshielded electronics in the way until something else shut it down. I'm sure the multiple layers of government regulators will ensure a lot of "deadman switches" to stop the only thing that everyone guesses could go wrong.
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Re:Bad idea (Score:4, Funny)
Re:Bad idea (Score:4, Funny)
That's not a horrible idea... that's a fabulous idea :)
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So, no effect then.
I've seen this (Score:3, Interesting)
They mentioned it in the first Robocop movie.
Re:I've seen this (Score:5, Funny)
Fools...
Comment removed (Score:3, Insightful)
Re:In all seriousness... (Score:5, Funny)
Re:In all seriousness... (Score:5, Funny)
Re:In all seriousness... (Score:5, Insightful)
Yes. But as the Russians found out - any energy source can be used as a weapon. The more people are dependent on it, the better. And such usage doesn't even involve violence - just mention that there might be some service disruptions, outages, etc, if you don't get your way.
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Re:In all seriousness... (Score:5, Funny)
I'd be interested to know what effect it would have on an airport for example.
The in-flight meals would be warm for once. Now, if only someone could work out a way of beaming flavour from a satellite...
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What is this in-flight meal you speak of?
Re:In all seriousness... (Score:4, Funny)
They're a device designed to prevent passengers becoming bored and restless on longer flights. Originally they were cheap cardboard construction kits, but the airlines found that by serving them with gravy mix they had greater entertainment value.
Re:In all seriousness... (Score:5, Funny)
couldn't this also be used as a weapon?
"Tonight we had a most unfortunate accident. A micrometeor hit the satellite, changing it's orientation. The accident, unfortunately, destroyed a coal plant. Again.
Oh, by the way. We're raising the prices 25%."
Re:In all seriousness... (Score:5, Insightful)
No, it will never get off the ground.
Having said that, Solaren's web site is all about down to earth renewable projects. The 200MW of power the power company has pledged to buy is the equivalent of 40 commercial windmills. My guess is this is a "foot in the door" deal that cost neither party a cent but Solaren now know what the power company are willing to pay. Using this knowledge they can go back at a later date and convert the pie-in-the-sky pledge into a purchase from a normal wind/solar farm that will do the same thing for the same predetermined price.
makes no sense (Score:3, Insightful)
If you're lucky, you gain a factor of 2-4 in efficiency by going into space, but the costs per photocell are astronomically higher compared to installation in a desert.
That's, of course, assuming you can actually get other nations to agree to let you place a massive power plant and emitter in orbit, something that could easily be weaponized.
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Ya know what else is astronomically more expensive? Getting power from a desert to where it is needed, and buying all that land in a desert. I'm not saying SSP is remotely close to being cost effective yet, but there's simply more to crunching the numbers than you think there is.
Re:makes no sense (Score:5, Interesting)
Buying desert land isn't "astronomically expensive". It's about the cheapest land there is. There happens to be huge deserts of dirt-cheap (cheaper: sand-cheap) land all around California. Besides, this 2MW satellite probably doesn't even need more than about 25m^2 to receive its beam at 5x solar density. If they wanted to be really safe, they probably could diffuse it over 2500m^2, for 5W:m^2, which doesn't hurt anyone.
The efficiency here is the 30% extra incoming solar power that is otherwise lost in the atmosphere (minus some small lost amount they're tuning the beam to minimize), times the 24/7 uptime instead of about 25% terrestrial due to night/weather/seasons. That's a starting point of 520%. But the other advantage is the much larger area that thin collector sheets can cover in space. Launching costs money per mass, but the collectors can unfurl across kilometers. And the maintenance costs in microgravity/femtopressure are much lower over years, despite the remoteness. After the large initial costs, the ongoing costs per watt are extremely low.
2MW would require only about 40x40m collectors. A square kilometer collector would bring 1.3GW. The geosync satellite beaming to Fresno could receive from collectors in all kinds of other orbits pointing at the hub. This infrastructure could conceivably bring all 17TW of Earth's energy consumption into a series of ground stations from only about 114*114 Km of collectors. A few score hubs around the equator each using a few dozen GW lasers could replace all the coal currently burned for stationary power. The sky is literally the limit.
Re:makes no sense (Score:5, Informative)
During most of the year, geostationary satellites spend 100% of the time in sunlight. During "eclipse season" (which happens around the spring/fall equinoxes), they get eclipsed, for a few minutes up to about 70 (at the peak of the season). A discussion of this can be found here: http://celestrak.com/columns/v04n09/ [celestrak.com]
During those times, you could redirect from another satellite, use an alternative power source (batteries, capacitors, fueled generators, etc), and/or have a "brownout". Power outages suck, but if you're in a place where conventional power sources are unavailable/impractical/infeasable, it's better than nothing.
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The only other factor that I can think of are land cost and maintenance costs. I'd assume you'd still want a large area of land, just in case the system should go off course, so that one might not be a significant difference, so that just leaves us with maintenance -- how much effort is it to keep a similarly producing land-based system, vs. keeping an eye on the satellite and keeping a smaller ground-based receiver going?
Not a problem, don't be such worrywarts (Score:5, Funny)
As long as you turn off disasters, beamed solar energy is actually a fairly cost effective power solution.
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But what's the fun of playing without the disasters?
Re:Not a problem, don't be such worrywarts (Score:5, Insightful)
I sometimes wonder if SimCity has done more damage to the progress of orbital solar than all other causes combined.
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I would think that the real problem is that Uranus jokes is driving research away from the 7th planet.
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Re:Not a problem, don't be such worrywarts (Score:4, Informative)
I mean, what's the worst that can happen when you're beaming 200 Megawatts of energy into my town?
Right now a fusion reactor is beaming sunlight (@ 1366W per square meter [wikipedia.org], on average) * 271.4 square km [wikipedia.org] of energy at luminal frequencies alone which if I do the math right (even at this level it is by no means sure, I could be off by three orders of magnitude or something, yes I am that dyslexic about numbers) works out to about 370 gigawatts.
The amount of energy is pretty irrelevant by itself, aside from what it can add to the grid.
To answer the inevitable question (Score:2)
No, these don't work like SimCity. The microwaves are not the frequency used in ovens -- ie that heat up water. Otherwise they wouldn't be much use on a cloudy day.
It's a very positive development. Orbital solar power is the best foothold for the colonisation, industrialisation and settlement of intrasolar space.
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Near the receiving station, there is no such thing as a cloudy day.
Especially if it is the same frequency as water.
"Fresno, home of the 5 minute tan!!*"
*: Some limitations apply.
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You've misread me. I said it does not interact with water.
The point is that if you want to transmit power, you want to minimise power losses. If you choose a frequency that does not interact with atmospheric gasses -- including water vapour -- then you minimise those losses.
It does not interact with water, including the water which makes up your person.
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Pretty much any time orbital solar gets discussed on Slashdot, there's a bunch of jokes about Sim City, somebody wonders if it can be weaponised and somebody else thinks we're all going to be cooked. It makes me grind my teeth, orbital solar is one of my areas of interest. Usually I'm too late to add to the discussion, but not this time! :D
Still, for a bunch of geeks, Slashdot users sometimes seem to know very little about space. :/
It think they've been duped. (Score:4, Interesting)
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Or are they really saying they're going to install roughly 200000 m^2 worth of solar collectors in space? That's a square of roughly 450x450m. And "some startup" is planning a feat like that?
Nope. The amount of sunlight per m2 in space is several factors higher than on earth.
Re:It think they've been duped. (Score:4, Informative)
Plus in space solar power is available constantly, rather than being affected by night time, winter hours and weather. As they point out you don't have to pay for the real estate, just the trip to get there.
And it gives more consistent power because you don't get dust settling on the panels. I realise that sounds stupid, but dust can reduce efficiency by a lot in a few years; your costs go up because you have to pay people to be cleaning acres and acres of solar panels.
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Re:It think they've been duped. (Score:4, Informative)
There are a number of points you can choose that are geostationary and in shadow less than 2% of the time (as I recall the 1970s proposal). Other schemes call for having multiple satellites that hand off to each other. This proposal is I think of the former variety.
Re:It think they've been duped. (Score:4, Informative)
The trick to remember is that the Earth is actually quite a small part of the sky when seen from a satellite in geostationary orbit. It seems big to us, but it's just a pale blue dot after all.
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Not really. A Geostationary orbit (over the same point) would cut through Earth's shadow for about 45 minutes on orbits where the orbital inclination lines up with the sun... generally in the spring and fall. Other times, the orbit is up to 23 degress off the Earth-Sun plane, and not in the shade at all. Since this power interruption would occur at "midnight", it probably won't affect peak power usage at all. And if you pu
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It's not in geosynchronous orbit. Duh.
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This _strongly_ depends on your orbit and your technology. Unless your collector is a sphere of solar cells, your collector or reflector arrangement will get different efficiencies depending on where it is pointing relative to the Sun. And for many geosynchronous orbits, the Earth will occlude the sunlight in the middle of the night.
Now, the currently available geosynchronous orbital space is dangerously cluttered. Big mirrors there are begging to get hit by satellite debris. A reasonably large solar mirror
Re:It think they've been duped. (Score:5, Insightful)
The solar constant is about 1.4 kW/m^2 in Earths orbit. I fail to see how they want to produce 200 MW with significantly less than 0.2 km^2 of collector area. Care to explain it to me?
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Re:It think they've been duped. (Score:4, Informative)
How about I convince you they're planning to deliver only 2MW, not 200MW.
They say they'll reach a 17GWh:y delivery once the platform is stable. There's 8765.81277 hours in a year, so that's 17 billionWh / 8765.81277h = 1.9393524 million watts.
The solar "constant" [wikipedia.org] in geosync Earth orbit (about 35Km elevation) is 1366W:m^2. That's 1419.73089m^2, or 0.00141973089Km^2, significantly less (0.709865445%) than 0.2Km^2.
Re:It think they've been duped. (Score:4, Informative)
TFA's math is wrong. TFA says specifically
1700 GWh in an 8700 hour year is just under 2MW. 200MW is enough power for 100,000 homes at 2KW each (a low average), so even their math that 1700GWh is "the annual consumption of 250,000 average homes" is wrong. I think their quoting the numbers in the contract is more reliable than their arithmetic.
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1. Orbital solar platforms cannot be used as weapons unless you are trying to drop them on someone (which is true of anything in orbit). The energy they put out is the wrong frequency; it doesn't interact with human biology at all.
2. If you can build 25 ton to LEO heavy lifters, James Bondesque schemes are a waste of time. Better to lob nukes. Heck, even throwing a 25 ton block of concrete on a ballistic course would be more far, far more dangerous than 100 years of orbital solar power transmissions.
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Well, does it interact with anything else? Communications, airplanes, missiles, buildings? Who says that a weapon needs to be able to kill people?
Other uses . . . (Score:2)
Maybe a bunch of these could be used to block out the sun, and thus, reverse Global Warming?
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1. Very expensive way to perform geoengineering. There are cheaper proposals (iron seeding, spray boats, atmospheric particles etc) around.
2. Sunlight exerts pressure, so if it's not in an orbit, it will soon be on its way out of the solar system. There was a proposal to build fresnel lenses instead.
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maybe they are thinking to reuse all those progress solar panels instead of burning them together with the spaceship.
Goodbye Alexander Adell and Bertram Lupov. (Score:2)
Took us long enough [multivax.com].
Excellent headline (Score:5, Funny)
"PG&E Makes Deal For Solar Power From Space"
Is there any other kind?
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It depends on what sort of arse you have. There are some who believe that they can generate anal solar power.
Fresno... (Score:2)
This is an excellent use for Fresno. I approve.
Discovery Documentary (Score:3, Informative)
I found it extremely fascinating and was wondering if it would just die or if there would be some actual results from the project, seems like we are getting somewhere now!
I remember from the documentary that the biggest problem was the beam being split in two, rather than one focused beam. Hopefully they found a solution to this problem.
Anyways, I strongly suggest watching the documentary if you are interested in this, it really shows how the idea was born and all the small advancements they made which resulted in a successful test.
"unaffected or Earth's day-night cycle" Really? (Score:2)
"space satellites could generate power 24 hours a day, unaffected by cloudy weather or Earth's day-night cycle."
That might be true depending on the orbit. If it's in an expensive synchronous orbit it will still be in earth's shadow once a day but I would expect that the beam would have a pretty large diameter at Fresno. If it's in any other orbit Fresno will be in line of sight for only part of the time. So how do they generate and transfer power over 90% of the time?
Forget Earth weather, think about space weather. (Score:2)
One good coronal mass ejection, and these things are toast, I would assume.
ok, wait a second (Score:3, Insightful)
I am really a supporter of solar energy - I even have invested some of my money in it - but THIS to me seems like technological masturbation. I do not believe it's cost-effective, and the debris in orbit is only going to increase, so it's a risky investment in any case.
Leik Myrabo FTW (Score:2)
I had a lunatic prof in college who advocated this stuff, along with laser powered lightcraft. The technology really works - as he put it, if we can hit an ICBM at Mach 20 with a laser, we can hit a spot on the (relatively) unmoving Earth with a laser.
Sim City anyone? (Score:2)
I'll uh, believe it when i see it. (Score:2)
These guys made this deal so that they can get investors and loans to build the thing. It's no risk to PG&E, and now these guys have to execute.
In other news... (Score:2)
...Solaren was purchased by the Mikado Group, whose chairman, Dauragon C. Mikado, says that the satellite plan will bring ultimate power...
listens to the crickets
Yeah...didn't expect many people to get that reference.
Dan Aris
I hope this is a joke.. (Score:2, Interesting)
...otherwise kiss radio astronomy in North America goodbye. Those guys thought they were getting interference from the Iridium constellation? Heh..wait until they get 200MW of broadband RF interference coming down on them from this monstrosity.
Not to mention, this seems to be a complete waste of resources. I'd wager that at least as much land (if not more) will need to be dedicated to the antenna array as a 400MW (put in twice the power to make up for day-only operations) solar concentrator plant if they
SPSS (Score:4, Interesting)
This really is very safe, and all the technology is known (not at this scale maybe, but known). The only thing that has stopped us from doing it already has been a lack of willpower.
If you are sending microwaves from a smallish antenna (small enough that you can boost it into GEO, for example) all the way back to earth, the receiver needs to be huge, like many acres. Basically you find a good pasture, put posts in the ground every few dozen feet in a grid, run wires and diodes between the poles, and you now have a high efficiency rectenna and the cows grazing underneath won't even notice.
Even if the beam wandered, the power per square meter isn't that high, and to get through the atmosphere with minimal losses, it won't be at a frequency that is easily absorbed by water, which means that it won't be at a frequency that is easily absorbed by you or me.