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# This Satellite Could Be Beaming Solar Power Down From Space By 2025

#### timothy posted about a year ago | from the your-popcorn-isn't-safe dept.

245

Daniel_Stuckey writes "A NASA veteran, aerospace entrepreneur, and space-based solar power (SBSP) expert, [John] Mankins designed the world's first practical orbital solar plant. It's called the Solar Power Satellite via Arbitrarily Large PHased Array, or SPS-ALPHA for short. If all goes to plan, it could be launched as early as 2025, which is sooner than it sounds when it comes to space-based solar power timelines. Scientists have been aware of the edge the "space-down" approach holds over terrestrial panels for decades. An orbiting plant would be unaffected by weather, atmospheric filtering of light, and the sun's inconvenient habit of setting every evening. SBSP also has the potential to dramatically increase the availability of renewable energy."

cancel ×

### Could? (0)

#### Anonymous Coward | about a year ago | (#44668473)

Only if with could you mean won't ...

### Re:Could? (0)

#### Anonymous Coward | about a year ago | (#44669069)

Only if with could you mean won't ...

All we need is a big, long extension cord and it'll work great. After 50 years it might even generate as much energy as was used to put it in orbit!

### My god, what has science wrought??? (5, Funny)

#### kruach aum (1934852) | about a year ago | (#44668475)

A satellite directly beaming solar power down from space? We've created... the moon.

### Re:My god, what has science wrought??? (2, Funny)

#### Anonymous Coward | about a year ago | (#44668601)

It basically works like Ion Canon and it will accelerate global warming and destroy the receiver station.

### Re:My god, what has science wrought??? (3, Informative)

Ion Canon

I think you mean "ion cannon" unless you're talking about the definitive collection of published works on ions.

An ion cannon works by projecting a beam of charged particles, either atoms or molecules, not a beam of microwave energy.

And, no, it's not going to destroy the ground station.

### Re:My god, what has science wrought??? (4, Funny)

#### You're All Wrong (573825) | about a year ago | (#44668605)

The moon's too lossy, and keeps having its time of the month where it's completely useless. For getting solar power beamed down from space, I'd propose using ... the sun!

I'm curious - how much taxpayer funding has this received? Is this just another one of the "ride the replace-fossil-fuel-usage bandwagon" schemes?

### Re:My god, what has science wrought??? (4, Insightful)

#### mcgrew (92797) | about a year ago | (#44668841)

I'm curious - how much taxpayer funding has this received?

Less than a day's worth of military funding, I'm sure. And this is not an expenditure, it's an investment.

### Re:My god, what has science wrought??? (1)

#### modernbob (558981) | about a year ago | (#44669021)

Yeah we could have 50 of theses for the price of the iraq war.

### Re:My god, what has science wrought??? (5, Interesting)

#### Dereck1701 (1922824) | about a year ago | (#44669025)

"Less than a day's worth"

You''re being WAY to generous, the US military spending for 2012, ignoring all of side costs (possibly as high as $500 Billion) is roughly$900 Billion dollars. Broken down to a "By Day" cost it is $2.46 Billion per day, with that kind of money you could probably finish development and put a significant amount of this concepts hardware into orbit. If any taxpayer money was used on this study it would probably be measured in seconds of military spending (~$28,500 per second) at most.

### Re:My god, what has science wrought??? (0)

#### Anonymous Coward | about a year ago | (#44669101)

Maybe 10 minutes of social programs funding.

You do realize NASA's annual funding is $18 billion and social programs at the federal level$2,300 billion. The entire NASA budget would fit neatly into 3 days of welfare. (We won't even be cruel and throw in state and local which pretty much doubles it. (Military btw is 600 billion annually) ### Re:My god, what has science wrought??? (4, Insightful) #### hedwards (940851) | about a year ago | (#44669317) I can't help but notice that you're comparing with social programs, and the DoD, which is grossly overfunded, is thrown in as an after thought. Goes to show why the US is in such trouble. Wellfare programs are essential, but get relatively little money. But, the DoD, gets a crap load of money, with little or no benefit for the funds. What's more, a huge number of the people on welfare are there because we signed all those free trade agreements and shipped the decent paying jobs overseas. All while making it harder and harder for employees to organize, and slashing taxes that the rich pay. ### Re:My god, what has science wrought??? (1) #### Anonymous Coward | about a year ago | (#44669315) and keeps having its time of the month where it's completely useless Huh, just like a girlfriend! ### Re:My god, what has science wrought??? (3, Funny) #### Arancaytar (966377) | about a year ago | (#44668929) Moon, Death Star, whichever. ### It's all good until (1) #### Anonymous Coward | about a year ago | (#44668479) the microwave downlink gets misaligned and burns down the city block next to the ground station. ### Re:It's all good until (2) #### Zumbs (1241138) | about a year ago | (#44668567) the microwave downlink gets misaligned and burns down the city block next to the ground station. TFA seems to imply that they considered the issue of using lasers and shot it down with the words: High frequency blasts can damage retinas, destroy electronics, and potentially ignite fires or explosions. “Think about the Death Star,” he warned. The risk factor outweighs the seductive, compact grace offered by lasers. As you note, however, microwaves are not entirely safe either. On the other hand, if the intensity is low enough it should be safe, which is what is being discussed: Since Mankins is dead-set on low-intensity microwave transmitters, the receiver on Earth will be large—about 6 to 8 km in diameter, positioned 5 to 10 meters above the ground. The obvious question is if the beams can be focused, and used as a weapon, it could provide a no-warning and very destructive attack anywhere in the world. It seems to be what Mankins is trying to avoid, and I tend to agree that (aside from cost) we really, really need to make sure that the power sources of the future are not just being used to cloak the real objective: Making powerful weapons. Example: Nuclear power. ### Re:It's all good until (3, Insightful) #### Spottywot (1910658) | about a year ago | (#44668647) It seems like the fear of weaponisation is whats kept this sort of thing from being explored more fully, up till now of course, but I think that there are logical arguments that prevent this from being an issue. For instance if country 1 put up enough of these things they would be able to supply a large proportion if not all of their countries energy needs creating a significant economic advantage for country 1. Said country then decides to point one elsewhere to burn down a city or military installation in country 2 therefore breaking the International space treaty and probably many others, and the international community forces country 1 to dissasemble their SPS-alpha capability, causing them severe economic dissadvatage. TLDR using these as weapons makes no economic sense. ### Re:It's all good until (1) #### maxwell demon (590494) | about a year ago | (#44668665) The problem is: How do you prove that it was an intentional event, as opposed to a malfunctioning of the controls? Or what if one country hacks into another country's control system and uses one of their satellites as weapon? If the satellite happens to be on the other hemisphere (so there's no danger of accidentally hitting the own country), they don't even need to have control. Just DoS the other country's control, and have the out-of-control satellite burn populated areas at random. ### Re:It's all good until (1) #### ChrisMaple (607946) | about a year ago | (#44668923) Gee, don't you think the designers would plan for something like ground control failure? ### Re:It's all good until (1) #### MysteriousPreacher (702266) | about a year ago | (#44668993) The problem is: How do you prove that it was an intentional event, as opposed to a malfunctioning of the controls? The same way it's done when a malfunction causes a nuke to be fired at another nation? Or what if one country hacks into another country's control system and uses one of their satellites as weapon? If the satellite happens to be on the other hemisphere (so there's no danger of accidentally hitting the own country), they don't even need to have control. Just DoS the other country's control, and have the out-of-control satellite burn populated areas at random. It's a risk, and so is pretty much everything. Nuclear plans, research facilities handling hazardous biological materials. One would hope these satellites would have a few fail safe mechanisms built in to them: 1) Suspend the beam if contact with control is lost. They'd be pretty amateurish if they designed this so a DoS could allow people to use it as a weapon. 2) Isolated systems to confirm the location of the beam's target, and to shut down necessary systems if the beam is headed for unrecognised locations. 3) Require significant delays in re-activating beam when the satellite has been moved or reoriented. 4) Some kind of feedback from the surface, so if the beam is directed anywhere but a proper land station it will be cut off. 5) Emergency cut off that prevents the beam from being reactivated for x amount of time. Full disclosure: I'm neither a space energy beam designer or a layer. ### Re:It's all good until (1) #### hedwards (940851) | about a year ago | (#44669331) That's sort of how it's done with nuclear power, the control rods default to being all in the core and the fuel rods default to being out of the core. So, barring the case where something comes in and prevents that from happening, the reaction comes to a gradual slow down and stops. Presumably, a satellite like this would be designed to default to off and require intervention to keep it on. ### Re:It's all good until (2) #### Spottywot (1910658) | about a year ago | (#44669089) The problem is: How do you prove that it was an intentional event, as opposed to a malfunctioning of the controls? Or what if one country hacks into another country's control system and uses one of their satellites as weapon? If the satellite happens to be on the other hemisphere (so there's no danger of accidentally hitting the own country), they don't even need to have control. Just DoS the other country's control, and have the out-of-control satellite burn populated areas at random. Something like a system whereby the satellite will only transmit when it is within a fraction of a degree of its normal orientation, or a signal constantly transmitted by the base station when it is receiving, a combination of both. That's just off the top of my head while I'm at a party I'm sure the researchers involved have thought about this a lot. ### Re:It's all good until (1) #### ChromaticDragon (1034458) | about a year ago | (#44669067) I'm not quite sure I entirely follow your logic or agree with your assumptions/conclusion. You're surmising it doesn't make economic sense to use these as weapons simply because you've assumed the international community will be able to dictate that the offender dismantle the entire fleet of satellites? Let's back up a bit. Not that it's entirely clear in your portrayal, but if country 1 is the only country with these things... and a lot of these things... I don't think it would be an "oops" moment after the attack. I think it would be a "...this Death Star is FULLY OPERATIONAL" moment. This wouldn't be dampened by MAD unless many countries had similar weaponized satellites in similar quantities. This also wouldn't have the stigma of fallout, radiation or other lingering effects. It may also likely be able to be scaled to knock out someone walking to work or entire cities. It would make as much as economic sense as the ability to control masses ever has. At least one science fiction book had this as a premise. My Google-Fu is weak at the moment. But I seem to recall the general idea was the French took over the world in exactly this manner. Mind you, this had nothing to do with the plot... ### Re:It's all good until (1) #### hedwards (940851) | about a year ago | (#44669353) Most likely this would be restricted to countries like the US that have a huge amount of space that's largely uninhabited. Unfortunately, I'm not aware of any such nation that's also located close enough to the equator to have a geosynchronous orbit. IIRC, you really need to be within about 10 degrees of the equator, or something like that. If you get too far away, then the speed necessary to keep the satellite in orbit prevents it from staying directly above the receiver. The other alternative would be figuring out how to put the collector in the middle of the ocean, but the task of getting the power back to land, would be a challenge on par with the rest of it, and would likely be hugely inefficient. ### Re:It's all good until (1) #### Zumbs (1241138) | about a year ago | (#44669087) I don't think it is intended to just power one country, but many. So, if country 1 produce a vast surplus and exports it to many other countries, these other countries may not be so fast to want it dismantled. Also, if it is feasible, it may not just be one country putting them up. Once one country do and they do have weapon potential, many of the other nuclear powers will. At the moment, this may not be a problem, but if a new cold war should arise, the full attack with no warning may make some hawks push for a preemptive attack. ### Re:It's all good until (Cost Benefit Analysis) (2) #### rgbatduke (1231380) | about a year ago | (#44669187) The obvious question is if the beams can be focused, and used as a weapon, it could provide a no-warning and very destructive attack anywhere in the world. It seems to be what Mankins is trying to avoid, and I tend to agree that (aside from cost) we really, really need to make sure that the power sources of the future are not just being used to cloak the real objective: Making powerful weapons. Let me help you with that. The answer to your obvious question is "yes". Hence the problem... Of course there are dozens of ways to use a high orbital position to control the Earth. Nuclear armed satellites. Project Thor. A nice collection of medium sized asteroids movable/targetable by means of e.g. Orion (small nukes used to push them, solar powered ion jets or solar sails for finer control). I worked through the physics of this out of sheer curiosity a few years ago, and no, it really won't ever really be "safe", nor will it ever be cost effective. It is, in fact, a really stupid idea as far as I can tell. Solar cells are cheap and plentiful right here on the Earth, and are getting cheaper all the time. If you take a square kilometer of the Earth's surface, you have order of million square meters of collector (times cosine theta). On a cloud free day, you have anywhere from 700 to 900 watts/m^2 hitting the collector panels (peak a bit higher, these are sort-of-averages). Depending on the kind of panel, you get (say) 10% conversion (cheaper panels get less, more expensive ones get more). Call it 90 watts per square meter. Your one kilometer square area thus yields ballpark of 90 megawatts -- but let's say only 50 (and of course, only during the daytime). 20 square kilometers is thus a gigawatt plant, which is quite respectable -- an area some (say) 5 km squared, allowing for roads and access and the need to be able to tip them through at least some angle to maintain a small angle of incidence as the sun moves overhead. The cost per watt of the panels is order of1 (probably less, at this scale). The cost of the land is whatever we want it to be, if we use public lands or inexpensive fallow lands that cannot be used for much else (abundant in the southwest, less so in the more developed midwest and east). Let's presume that the additional cost of the land, the electronics, and at least a modest storage array to buffer small fluctuations in power delivery is another $1/watt. You end up with a 1 GW plant for 2 billion dollars, which is actually not particularly crazy even now in places where electricity costs a lot (which is why private citizens are doing it). In reality, I think it would end up costing maybe half of this by the time economies of scale kicked in, which would give you an amortization time of less than a decade on the initial capital investment and at least a decade of pure profit. Not the fastest way to make money, but not a money loser and in a market dominated by low interest rates a not unreasonable ROI. Now take the same solar panels -- the EXACT same solar panels, mind you -- into orbit. A couple of useful (approximate) numbers. It costs 64 megajoules to give 1 kg escape velocity (1/2 times 1 kg times (11.2 \times 10^6)^2). An orbit costs anywhere from 1/2 of this to the full amount, depending on the orbit. A geosynchronous orbit would actually cost most of it at 5 R_e -- call it 50 megajoules per kilogram. Of course, this is the pure energy cost at perfect efficiency. In fact, the cost in US dollars per kilogram in GEO is order of$10,000!

Assuming -- not unreasonably -- that the solar panels we lift into orbit mass out at a 100 grams per square meter, and are absolutely egregious in assuming that they get ten times the power per square meter compared to collectors on the Earth's surface (2-3 from higher insolation, the rest from extending "daylight" hours by a factor of almost three, still leaves us short but with round numbers) we can, indeed, get our (earth surface equivalent) orbiting GW at an equivalent cost factor of roughly 100. That means that the GW in orbit has -- so far -- cost roughly 100x as much as the same GW on earth, adjusting for for both smaller size, less atmospheric attenuation, and a higher duty cycle. This neglects, for the moment, the absolutely enormous costs of doing ANYTHING in orbit (outside of these direct platform delivery costs to lift it up there) that would almost certainly multiply this additional cost by a hundred -- lifting humans into orbit to build it, lifting a space station into orbit for the humans to live in, lifting tools and fuel for people to use to move cells around, dealing with orbital debris, micrometeorites, the risks of blowing the entire grid in the blink of an eye the next time Mr. Sun decides to fire even a modest CME at the Earth, the problem of radiation, the fact that if you're going to be spending all of this money lifting cells into orbit making them still more expensive cells is negligible (putting you still more at financial risk of CMEs) which I think are all collectively a deal killer -- CMEs are a deal killer all by themselves -- and return to the Earth. IMO one would be fortunate indeed to build a GW scale solar collector for less than 100 billion dollars, with absolutely enormous maintenance and repair costs and with a huge risk of something coming along and trashing the whole 100 billion dollar investment in the blink of an eye.

But fine, OK, there you are in space with your hundred billion dollar GW space collector (or make it ten billion dollars, if you like, I don't really care as it is already a dead loss per delivered GW-equivalent compared to the ground). It's ticking away, turning sunlight into energy. You need to get the energy back to Earth. So you transform it -- at some loss -- into microwave energy directed towards the ground. How this is accomplished -- magnetrons, ,klystrons, masers -- is immaterial. We can make microwaves. Next, we look for atmospheric windows in the microwaves spectrum avoiding e.g. oxygen peaks. Fortunately, the DRY atmosphere is pretty transparent to microwaves at frequencies in the general ballpark of 1 to 50 GHz, and microwave power transmission has long since been prototyped, but -- and here is the really important "but" -- only at intensities comparable at the receiver to the power leaked by a microwave oven, which is order of a 1 watt/m^2! This means that EITHER we increase the intensity substantially at the ground -- to, say, 100 Watts/m^2 or 1000 Watts/m^2 -- or else we need roughly 100 times the ground surface area that the solar cells needed to make the same amount of power would have required on the ground. Assuming 100% efficient conversion (and on a good, clouldless day with no attenuation from high humidity and/or liquid water in clouds and rain, they can get close to this) to receive 1 GW no matter how it is generated requires 1 billion square meters at 1 w/m^2, which is no longer a trivially small patch of ground a few miles square, it is hundreds of square miles -- some 30 km squared. Then there is the cost per watt per square meter of the receiver itself, which might actually be HIGHER than the cost of a solar panel -- remember, we are basically covering 30 km square with at the very least a web of resonant antennae with a high enough radiation resistance to completely attenuate/absorb the incoming energy.

Yes, you can increase the downward power, but by the time you reduce the costs to where the ground collector alone doesn't cost as much as the entire solar array built on the ground would have cost, you're up there where the downward intensity is no longer manifestly harmless, and your phased array transmitter is a tiny tweak away from being a weapon capable of anything from blowing electronics from space (e.g. taking down the cell phone grid) to literally cooking people who aren't wearing their tinfoil hats. And frankly, even the low intensity option is a slightly larger tweak away from the same thing.

I simply was unable to work the numbers on this, making any reasonable set of assumptions, and ending up with an orbital solar collector being anything but a very expensive boondoggle, a way of spending truly enormous amounts of money compared to almost any mechanism you can imagine for generating electricity on the ground. No matter how you slice it, the cost per kilogram of lifting any sort of mass you like into GEO or GTO is prohibitive. If we invested a TRILLION dollars or so in building a linear mass accelerator that e.g. ramps up the side of the Andes or the rockies (assuming that even that, with rocket boost, and long term placement with light sails) we might get the costs per kilogram down to make it feasible, but at a butt-kicking amortization as no matter how you slice it a trillion dollars ain't chump change.

In any event, this whole discussion is moot. Within the next ten years, the cost of ground based solar will drop to where it starts spreading out all over the world not to save the world, but to save money, as it will be one of the least expensive forms of energy amortized over maybe 7 years for a factor of 3 to 4 to 1 ROI over its lifetime. Ordinary people will build it into ordinary houses, and economies of scale will drop costs still further. Long before 25 years are up, solar will be generating a large fraction of our energy, and there will be EVEN LESS cost benefit compared to ground based solar, because as it is now, you could make the solar cells FOR FREE and shoot them up into orbit and it wouldn't matter. The cost is all in getting them into orbit and getting the power back to the ground, not in the solar cells themselves. The cheaper a solar cell gets, paradoxically, the LESS economic sense it makes to lift them into orbit as we'll always do better adding 100 GW of ground capacity compared to 1 GW of orbital capacity (all "equivalents", factoring in duty cycle). What we really need to do is work on e.g. nuclear power to bridge the gaps, because even GEO orbital power is going to be interrupted when the station is eclipsed OR we'll have to build a huge overcapacity, deal with transmission along a non-zenith line, deal with transmission on the ground (which is where it might MAKE SENSE to use microwaves -- built a network of evacuated wavesguides to beam power from coast to coast and equator to the poles, at least until somebody solves the problem of superconducting long distance power transmission), and, of course, multiply costs and risk still further.

### Re: It's all good until (0)

#### Nutria (679911) | about a year ago | (#44668809)

the microwave downlink gets misaligned and burns down the city block next to the ground station.

10 years ago, the first comment to an article such as this would have been about robots with Messiah complexes, and the second would have welcome our new Robot Prophet Overlords, IN SPACE!!

The science fiction nerd quotient of /. has tumbled.

### Re: It's all good until (1)

#### tmosley (996283) | about a year ago | (#44668861)

No, I think it would have been the same comment ten years ago, as that is a reference to the solar power station you can build in SimCity.

### -MICROWAVE POWER- in simcity 2000 (1)

#### Joe_Dragon (2206452) | about a year ago | (#44669153)

it should be hear in 2020 but in 2050 FUSION power is better.

### lol (4, Interesting)

#### etash (1907284) | about a year ago | (#44668491)

how exactly can it "revolutionize disaster relief" when it needs an almost 40km^2 (6-8km in diameter) receiver array on the ground to get the power beamed from the satellite. Disaster relief means fast deployment. How fast can you deploy a 40km^2 grid on the ground?

not even mentioning the fact that if you had 40km^2 of land you could just set solar panels there and do the thing for yourself with much less energy losses.

### Re:lol (2)

#### BlueMonk (101716) | about a year ago | (#44668549)

That does seem odd. I wonder if the 40km^2 is only required for large scale optimal receivers whereas if your power requirements were less or more of an emergency, less efficient receivers could be justified at a size that would be more portable and temporary.

### Re:lol (2)

#### etash (1907284) | about a year ago | (#44668557)

the large grid was - as the article says - not for better efficiency but in order to avoid the energy-beam weapon thing. by design the power beamed down spreads out a lot and thus requires such a large collector.

### Re:lol (1)

#### amiga3D (567632) | about a year ago | (#44668579)

Which makes me wonder, could this be used as a weapon as well? Why not design it so the beam can be focused and used as a death ray? This will enable DOD funding which should bring it into production ASAP. A dual purpose device for power generation or weapon of mass destruction.

### Re:lol (0)

#### Anonymous Coward | about a year ago | (#44668603)

You're thinking, "POPCORN!". ...right?

### Re:lol (2)

#### amiga3D (567632) | about a year ago | (#44668689)

Now that's "Real Genius" there.

http://www.imdb.com/title/tt0089886/ [imdb.com]

### Re: lol (1)

#### Anonymous Coward | about a year ago | (#44668611)

The number of nukes flying towards any nation trying to weaponize near-earth space, may give you a hint of an answer.

### Re:lol (0)

#### khallow (566160) | about a year ago | (#44668757)

The technology will improve. It surprises me how people can live any time in the last century and not get that a prototype is going to be a bit clunkier than the final products? A 40 square km antenna may be impractical even for a prototype, but a football field-sized ground antenna wouldn't be.

### Re:lol (1)

#### hedwards (940851) | about a year ago | (#44669365)

The problem there is that hitting a football field sized antenna is harder than hitting one that cover 30 square kilometers. You'd have to have a more advanced targeting system and you'd still have to put the most expensive part in space.

Also, nice mixing of units, can I get this in LoC or hogsheads?

### Re:lol (1)

#### Anonymous Coward | about a year ago | (#44668793)

Ummm... they basically are setting up solar power receivers across that 40sq-km of land, just tuned to a wavelength that is less affected by water vapor. They are also receiving far more than 40sq-km of source solar power in space, 24 hours a day.

IDK about disaster relief, but you certainly could make a nice weapon out of the power beamer, if that's your thing.

### Japan and the ESA are doing it too (4, Interesting)

#### AmiMoJo (196126) | about a year ago | (#44668499)

Japan is already working on a prototype solar power satellite. The ESA has an active project. I'd hope NASA could work with them on this one.

### Re:Japan and the ESA are doing it too (0)

#### Anonymous Coward | about a year ago | (#44668781)

Is this like the Ladder to Heaven competition?

### Nope. (5, Interesting)

#### Anonymous Coward | about a year ago | (#44668507)

The energy needed to put solar cells into orbit is not recouped over their lifetime outside the protecting atmosphere. Solar cells are used on spacecraft out of necessity, not because they're cost efficient.

I know this is an unpopular view on Slashdot, where atomic energy fans come together to bash all other technologies, but solar cells work fine on the ground. You can fill the supply gaps with conventional power plants and still come out far ahead CO2-wise compared to the current power mix. Production has hardly scaled up, but solar cells are already competitive in some markets. The point of these stories about satellite solar farms is to give you the impression that there needs to be some extraordinary investment or innovation before solar power can be used. That's a lie, designed to put a drag on solar power. Solar power is ready to be used, you just have to do it.

### Re:Nope. (-1)

#### Anonymous Coward | about a year ago | (#44668535)

Is there more than one Slashdot? The one I know is a heaven of anti-nuclear, pro wind-solar-fart-magic-power defenders. Even the editors are in that field, just look at what passes for news here: e.g. anything Fukushima related is plastered unto the main page in scary red letters.

### Re:Nope. (1, Insightful)

#### Anonymous Coward | about a year ago | (#44668581)

Editors are different, but a (compared to other fora) disproportionately large amount of Slashdot commenters seem to subscribe to irrational right-wing denialism of gun violence, anthropogenic climate change and the effects of Fukushima. Maybe related to being rich US men in tech jobs?

### Re:Nope. (0)

#### rubycodez (864176) | about a year ago | (#44669005)

some people stubbornly cling to facts. Like a small minority of the population, consisting of a couple subcultures, commits most the gun violence while the demographic that owns 90% of the guns has a crime rate comparable to homogeneous european countries. Total deaths from Fukushima disaster: zero. Total cases of radiation sickness from Fukushima disaster: zero. Total cancers caused by Fukushima disaster: zero.

### Re:Nope. (5, Insightful)

#### mark99 (459508) | about a year ago | (#44668547)

Agree with the poster. I figure solar cells in space will not trump solar cells on the ground until we dramatically lower the cost of delivery to orbit. At the moment we SpaceX is quoting 4300 USD/Kg to orbit on a Falcon 9 (1.1 - still waiting on maiden flight Sept5), and maybe down to 1200 UDS/Kg for the not yet built or demonstrated Falcon Heavy. And that is to LEO, Solar Cells probably need GTO which is about twice as expensive. I can't imagine a space based array can be competitive at those prices.
Now if someone built a rail-gun based launcher, then maybe it could make sense.
And as AC mentioned, we are in the midst of a ground based solar cell revolution right now. Very cool...

### Re:Nope. (1)

#### vtcodger (957785) | about a year ago | (#44668827)

I agree that putting a solar collector in orbit would be extraordinarily expensive using any currently extant technology. As would be maintaining it. On top of which, what would the point be? Solar energy can be collected on the surface at a small fraction of the cost and a technician can drive or walk to any component needing repair, Sure, a ground based facility might have to be larger than a space based facility, because of atrmospheric and sun angle losses. But not enough to make much difference?

BTW, I have to believe that a solar collector in orbit would probably constitute mankind's largest ever solar sail Is there some simple, cost effective, way to keep it from departing orbit on a journey in the general direction of Betelgeuse?

### Re:Nope. (1)

#### mark99 (459508) | about a year ago | (#44668869)

An ion thruster I suppose would do the trick. Of course it would run out of Xenon after awhile, but ion engines have the highest fuel to force ratios short of a solar sail.
Actually come to think of it I am not sure it is much of a problem. If you were in a geosynchronous orbit, surely the solar pressure would push you away half the time, but push you back the other half, right?

### Re:Nope. (3, Insightful)

#### ChrisMaple (607946) | about a year ago | (#44669015)

Although it may not be economical, there are significant advantages in space vs ground. Average daily insolation is at least 4X better. Because putting the space panels in place is so expensive, the fractional increase in cost of using high-tech panels is smaller: a 60% power/area (power/mass) improvement over single-crystal silicon.

As long as the solar pressure on the installation is less than the Earth's gravitational pull, it should be possible to design an orbit that will keep it in place. After all, when the installation is nearer to the sun than the Earth, the sun's radiation is pushinf it toward the Earth.

### Re:Nope. (0)

#### taiwanjohn (103839) | about a year ago | (#44668883)

Speaking of SpaceX, it's funny to hear Elon Musk talk about space-solar power. He absolutely hates it. The last interview I saw, he said something like, "It's so stupid! I wish I could just drive a stake through the heart of that idea, once and for all!"

### Re:Nope. (1)

#### drinkypoo (153816) | about a year ago | (#44669033)

If we had a space gun or a space elevator or space manufacturing then it would make sense. But you know what might make more sense? Nuclear plants in space, beaming down their power. Then you don't have to deal with all that surface area.

On the other hand, a space-based array could use roll-out thin film panels, because they don't have to resist gravity...

### Re: Nope. (0)

#### Anonymous Coward | about a year ago | (#44669247)

Sorry, but a railgun-based launcher doesn't make sense at all. There's all sorts of gun-based launchers that do, but railguns are hard enough on relatively easier (lower velocity, lower projectile mass) specs such as the US Navy's projects. Something like tbfg.org's [tbfg.org] proposed ram accelerator is much more feasible.

Might we, someday, be good enough at ultra-low-impedance machines that a railgun-to-space becomes feasible? Sure... but why wait around for that day when we have a good working grasp of the technology behind other designs? There's a world of cheap satellite comms* just waiting for cheap rides to LEO which will amply recoup the capital costs for the launch system, and meanwhile we can figure out the other applications (on-orbit fuel depots, space-based solar power, etc.).

* could/should end up as ubiquitous as cellular mobiles, but without the dead spots throughout most of the plains states, without needing a different phone for boaters over the horizon from land, etc. The only thing stopping this now is the ridiculous cost of launching the huge constellation you need for full coverage.

### Re:Nope. (5, Informative)

#### Anonymous Coward | about a year ago | (#44668565)

Here's some hard numbers on "traditional" approaches to solar ground vs space:
http://physics.ucsd.edu/do-the-math/2012/03/space-based-solar-power/ [ucsd.edu]
"You can even throw in batteries in the ground system without exceeding the space cost, and all the reasons for going to space have melted away."

It would be interesting if TFA had some hard numbers to compare against in terms of generation capacity vs launch costs vs upkeep/replacement schedule... Can't find anything myself though...

### Re:Nope. (1)

#### ChrisMaple (607946) | about a year ago | (#44669085)

Although the costs are hard to tie down, your citation seems to imply a disadvantage of space solar over ground of at least 4X, and some of the assumptions are open to challenge. Substantial improvements in a variety of technologies would be needed for space to be as practical as ground.

Still, I like the idea of at least doing some trial to work out bugs and make a standard for future experiments to be compared against.

### Re:Nope. (1)

#### Zumbs (1241138) | about a year ago | (#44668597)

You can fill the supply gaps with conventional power plants and still come out far ahead CO2-wise compared to the current power mix.

Not to mention that the periods where most power is being used is during the day, where solar power produce power, so solar power fits well with our current power consumption.

Production has hardly scaled up, but solar cells are already competitive in some markets. The point of these stories about satellite solar farms is to give you the impression that there needs to be some extraordinary investment or innovation before solar power can be used. That's a lie, designed to put a drag on solar power. Solar power is ready to be used, you just have to do it.

There is one issue with solar power (and a number of other renewable energy sources): They are not stable. Power output is dependent on weather patterns. Solar power has the additional issue that there is no output at night. The satellite solar farms is one way of getting around it. Another is to improve technology to store power, or to place solar power plants in areas where weather patterns are pretty constant (e.g. a desert).

### Re:Nope. (1)

#### JaredOfEuropa (526365) | about a year ago | (#44668921)

To what extent would the microwave beam be attenuated by weather (clouds etc)?

### Re:Nope. (1)

#### khallow (566160) | about a year ago | (#44668769)

The energy needed to put solar cells into orbit is not recouped over their lifetime outside the protecting atmosphere.

It doesn't take that much energy. I think it's more to make them in the first place. Well, maybe I'll run some numbers to see what the relative costs are.

### Re:Nope. (0)

#### Anonymous Coward | about a year ago | (#44669011)

Suppose you get 10Wp per kg, including all supplementary systems (heat management, positioning, transmission, etc.). Further suppose you can get that much energy 24/7, at the ground station (quite a generous assumption). Then you can expect about 900kWh per kg over a 10 year lifetime. That's equivalent to about 90 liters of diesel, or 90 USD at 0.1 USD/kWh. To put a payload of roughly 10000kg into GTO, an Ariane 5 rocket uses about 170000kg of LOX/LH2 and 480000kg of HTPB/AP/Al. Strike four zeros everywhere and you end up with 17kg of LOX/LH2 and 48kg of HTPB/AP/Al burned per kg of payload. I don't know what they're developing, but it's not for supplying electricity to the general population.

### Re:Nope. (2)

#### RicktheBrick (588466) | about a year ago | (#44668979)

I will believe in solar power when my electrical power company comes to me and wishes to rent my roof for a dollar a year to place solar cells there. When they think it is a great investment so will I.

### Re:Nope. (0)

#### Anonymous Coward | about a year ago | (#44669045)

That's being done in some countries, except they pay more than a dollar per roof and year.

### Re:Nope. (2)

#### tmosley (996283) | about a year ago | (#44669023)

That is why you don't lift the panels. Rather, you lift the equipment that needs to be built on Earth while sourcing that materials from somewhere off of earth. It's pretty low energy to get to geostationary from the moon. A captured asteroid would be even better. I wonder if it would be easy to make ultra-pure silicon in space?

### Re:Nope. (0)

#### Anonymous Coward | about a year ago | (#44669117)

Which, on the next step along the path of infinite regress, leads to the question of how the manufacturing facilities are going to get up there?

Long term, I don't doubt that we'll be manufacturing stuff in orbit, on a captured asteroid or on the moon. Right now it'd be like building an oil refinery in every town to avoid the cost of having to ship oil products separately around the country.

### and when something goes wrong.. (0)

#### Anonymous Coward | about a year ago | (#44668523)

can't wait for this to malfunction and cook my food in the backyard without any source but the beam......the grass might suffer but hey.

### Re:and when something goes wrong.. (1)

#### lennier1 (264730) | about a year ago | (#44668627)

Just place the ground station somewhere nobody will give a shit about, like Jersey.

### Re:and when something goes wrong.. (1)

#### Gaygirlie (1657131) | about a year ago | (#44668653)

can't wait for this to malfunction and cook my food in the backyard

This satellite wouldn't be capable of that. It does not use laser to transmit the beam down exactly because of the risks a high-power laser would pose if it ever were to become misaligned. No, this satellite transmits the power down via radio-waves and the biggest downside of that, if it ever were to become misaligned, would be haywire radio-equipment.

### Re:and when something goes wrong.. (1)

#### Lumpy (12016) | about a year ago | (#44668701)

Go find a discarded old style rear projection TV. disassemble to get the giant Fresnel lens out of it.

You now have your very own death ray that will set wet grass on fire and scorch concrete.

### Re:and when something goes wrong.. (1)

#### russotto (537200) | about a year ago | (#44669115)

You now have your very own death ray that will set wet grass on fire and scorch concrete.

Liar. I tried that last night and it didn't work at all.

### Control API Security (0)

#### Anonymous Coward | about a year ago | (#44668525)

As opposed to seemingly every other ICS out there, would someone please at least a security engineer before they design the control API for the thing?

### Re:Control API Security (5, Funny)

#### Kell Bengal (711123) | about a year ago | (#44668543)

would someone please at least a security engineer before they design the control API for the thing?

No. There's no pleasing security engineers.

### Re:Control API Security (0)

#### Anonymous Coward | about a year ago | (#44669013)

An attractive female skilled in the arts might please me. Even or should I say especially if she exploits some vulnerabilities... ;)

### Homer Simpson will be the safety / control room gu (1)

#### Joe_Dragon (2206452) | about a year ago | (#44669161)

Homer Simpson will be the safety / control room guy

### Great, another object in space (1)

#### Anonymous Coward | about a year ago | (#44668527)

Make it big enough and block the sun, then charge for sunlight. I can't believe that some huge corporation hasn't found a way to get people (members/users?) to pay for sunny days yet, but things like this should get that ball rolling.

### Everything old is new again (0)

#### Anonymous Coward | about a year ago | (#44668539)

I remember a proposal like this back in the 1960's. My first question then is my first question now: If a satellite can "beam down" enough power to be useful as a power source, how is it not an orbital directed energy weapon?

### Re:Everything old is new again (0)

#### Anonymous Coward | about a year ago | (#44668823)

It's never been abused before. There will be oversight by the operating organization. Consumer, please stand on your federally mandated GPS coordinates.

### Re:Everything old is new again (1)

#### ChrisMaple (607946) | about a year ago | (#44669109)

It is trivially easy to mechanically design the transmitting antenna so that the beam when it reaches the earth has a minimum diameter. The design being discussed has an intensity at the ground of 1/4 sun.

### It solves a non-problem, at very high cost. (1)

#### Anonymous Coward | about a year ago | (#44668545)

I don't see any need for this. Most cooling and heating uses of electricity can be easily moved from nigh-time to day-time, just like when mid-day electricity was peak price. Unless they can show that there overall price, including transport to space, monitoring and maintenance of space and ground equipment, transportation losses, etc. beat _ALL_ current and near-future electricity storage solutions by a large margin. I don't see that happening.

### what a euphemism (0)

#### Anonymous Coward | about a year ago | (#44668553)

Ancient:

causing Roman ships to burst into flame

Modern:

deliver power to any place on the ground that it can see

### Single Point of Failure 'Fail' (2)

#### TheRealHocusLocus (2319802) | about a year ago | (#44668573)

Energy is life and civilization. Balancing an industrial society on the razor edge of a single point of failure is itself a 'fail'. Whether the failure would occur technically or politically is of little consequence.

The catch-22 is impossible to avoid. If orbital solar doesn't scale then it is a waste of resource, if it does then it's a single point of (catastrophic) failure.

Terrestrial power plants can be replicated easily, hardened from sabotage, operated and maintained within many sovereign countries at once, can easily swap out parts. That is what you would wish to ensure the future.

### Re:Single Point of Failure 'Fail' (1)

#### thatkid_2002 (1529917) | about a year ago | (#44668753)

I agree about single points of failure, but I think some of your points are a bit of a stretch.
However, storing excess energy using hydrogen or molten salt might be good enough to keep things ticking over until repairs are done. But of course this is just a band-aid solution.
But obviously solar plants would be great for refining ore mined in space before it is plunged down to earth where energy is more expensive (or it could be manufactured further in space, eventually).

### Die another Day (-1)

#### Anonymous Coward | about a year ago | (#44668587)

How long until they try to melt my ice hotel? Solar power is too dangerous you insensitive clods! Even some schools let this dangerous cancer causing killer to hit our children! Demand a plan to stop sun violence! #ASES_IS_THE__kkk!!!

### Slashdot says "NO!" (-1, Troll)

#### Required Snark (1702878) | about a year ago | (#44668615)

All the Slashdot Pundits say this is clearly a bad idea. It's comforting to know that so many solar power experts, satellite engineers, power engineers, microwave antenna specialists, energy distribution specialists, system engineers, civil engineers, etc, have all been waiting here on Slashdot just for the moment that they can crush this awful idea before anyone takes it seriously.

If only the same Slashdot Pundits had existed in some form before the internet was created they could have shot that down as well. We would then be comfortably free of the internet, and the Slashdot crew could be practicing Morse code in their basements like god intended.

### As long as we keep it... (1)

#### Alejux (2800513) | about a year ago | (#44668631)

off the hands of Bond villains and other evil master minds...

### . . . IF MAN IS STILL ALIVE !! (0)

#### Anonymous Coward | about a year ago | (#44668697)

Oh, wait . . .

500 years on !!

### LOL (1)

#### sjwt (161428) | about a year ago | (#44668703)

In no way is this a "Lets put up a microwave beam weapon satellite and pretend that we are beaming power down by installing a secret Nuke reactor under a big dish."

### The real question is whether entropy is reversible (0)

#### Anonymous Coward | about a year ago | (#44668715)

Hey, the sun is going to run out eventually, no?

(Plagiat is intentional)

### So why not...? (0)

#### Anonymous Coward | about a year ago | (#44668729)

Solar power falls off as r^2 from the sun. So why not put a giant magnifying glass in solar orbit at 10% earth distance and as long as there is line of sight between this thing and the magnifying glass (you could deploy multiple to get line of sight all the time) then you increase the solar flux reaching the satellite 100x.

If you can get the magnifying glass at 1% earth distance then you can increase solar flux reaching this thing 10000 times. seems like relatively little work for a major pay off. Mine asteroids for the materials for the magnifying glass or you could built an inflatable one. It doesn't need to be a complex design.

### Re:So why not...? (4, Informative)

#### Culture20 (968837) | about a year ago | (#44668783)

Because solar orbit at 10% earth distance would make the magnifying glass zoom around the sun multiple times per earth year. There would be no way to get the rays from the glass to the collector. You'd be better off having the collector out there with an amiable maser.

### Re:So why not...? (0)

#### Anonymous Coward | about a year ago | (#44669199)

Point taken but still. I don't get why they are planning for earth orbit when some form of solar orbit offers improvements in the 2-5 orders of magnitude range.

### Aliens COULD be in control of our nation. (1)

#### ioconnor (2581137) | about a year ago | (#44668785)

Has slashdot decided to start republishing tabloid stories from the grocery lines?

### what could go wrong? (1)

#### csumpi (2258986) | about a year ago | (#44668801)

"convert that sunlight across a large radio frequency aperture into a coherent microwave beam and transmit the power to markets on Earth"

What could go wrong when pointing a large microwave beam at Earth?

### It's a cover (2)

#### MetricT (128876) | about a year ago | (#44668825)

Space-based solar doesn't make a lot of sense until we get a whole lot closed to a Kardashev Type I civilization than we actuallly are. There's simply no way that firing panels into space on a \$100 million dollar rocket is more cost effective than sticking them on the ground where Bob the Electrician can install and maintenance them.

It does make sense though in some *very* limit circumstances. If you frequently work in areas that have no power infrastructure, and can afford the jaw-dropping premium of space-based power. Those two facts suggest this is the public face of some kind of military or intelligence project.

### Prediction about 5 years too late (1)

#### NaiveBayes (2008210) | about a year ago | (#44668851)

According to Sim City 2000 we should be getting this by 2020.

### Sounds like the book Energized (0)

#### Anonymous Coward | about a year ago | (#44668859)

What happens if the microwaves beams are used as weapons against earth?

Spoiler alert, the book Energized by Edward Lerner (http://www.goodreads.com/book/show/13137561-energized) is about a power satellite that is taken over by bad people and used as a weapon against earth. Really good book.

Who gets to control the power? What kind of security is involved? Prelude to weaponization of space?

### It's safe up there (0)

#### Anonymous Coward | about a year ago | (#44668887)

"An orbiting plant would be unaffected by weather, atmospheric filtering of light, and the sun's inconvenient habit of setting every evening." This is wonderful as everyone knows there isn't anything in space that could fly into the thing now that all the asteroids, space junk and comet debris have been cleared from earth orbit forever.

### Used on Mars (0)

#### Anonymous Coward | about a year ago | (#44668893)

Maybe satellites could be used on mars to help keep colonists warm.

### How efficient is this thing? (1)

#### umafuckit (2980809) | about a year ago | (#44668913)

By the time you've taken into account the costs of launching this thing into space (and maintaining it) won't regular solar power work out as being more efficient? Alternatively, what about spending the money on developing more efficient solar panels?

### "no night" orbit? (3, Interesting)

#### dltaylor (7510) | about a year ago | (#44668915)

The only orbits that have no period when the sun is blocked by Earth's shadow ("night") are polar (remember the pictures of sunrise over the Earth shot from space by various astro/cosmonauts?). No single ground station could receive the power.

Also, there would be considerable photon pressure pushing the satellite(s) away from the Sun and, hence, Earth, plus gravitational drag attempting to pull the orbits around he Earth. Not a big deal for a short-term recon satellite, but these would be intended to there for years. Any of the rocket scientists out there know if the polar orbits are even vaguely stable, or will the satellite need boatloads of fuel to stay where it's needed. Of course, the beam of Earthbound power is a thruster, too, raising the orbit.

Put the collector at the Eath-Sol L1 and you've got to have REALLY good beam control to keep from raising the temperature of the entire Earth.

Sounds more like weapon than a power source to me.

### So... (0)

#### Anonymous Coward | about a year ago | (#44668947)

Why can't we do this, about a hundred times cheaper, on the ground?

Oh right, we need our gigantic orbital death lasers.

### JAXA already working on it (2)

#### Hebetsubeach (786552) | about a year ago | (#44669123)

JAXA (Japan Aerospace Exploration Agency) has been working on such a system from a number of years and plans to have 1-gigawatt space solar power system operating around 2030. http://www.jaxa.jp/article/interview/vol53/index_e.html [www.jaxa.jp]

### Been done with disastrous results (0)

#### Anonymous Coward | about a year ago | (#44669279)

I saw the disastrous effects of this very system on an episode of Futurama and everyone under the reflected light toasted into vapor.

Just sayin' -- you get your science from your sources, I'll get mine... etc.

### True Quantum Devices (1)

#### edibobb (113989) | about a year ago | (#44669309)

"the receiver on Earth will be large—about 6 to 8 km in diameter, positioned 5 to 10 meters above the ground. It will be constructed from millions of rectifier diodes—true quantum devices—wired together." I had no idea they've been building quantum devices since the 1950's.

# Slashdot: News for Nerds

This is clearly another case of too many mad scientists, and not enough hunchbacks.