Many other obstacles stand in the way of commercially viable SBSP. A crucial regulatory matter: getting clearance from the U.N.'s International Telecommunication Union (ITU) that allocates use of the electromagnetic spectrum. SBSP's ideal microwave frequencies are already used by wireless systems such as Bluetooth, according to Smith. "Even if we could narrow the beam [from space] down and ensure complete signal integrity in the broadcast wave area," the ITU may deem the possible interference from SBSP as too disruptive to some extant technologies, he says.
Some think that SBSP efforts should zero in on lasers rather than microwave transmission to avoid this and other confounding issues. "I think an approach using microwaves is doomed," N.Y.U.'s Hoffert says. Given the necessary size of microwave transmitters and their solar arrays, "it's a huge capital investment before you get one kilowatt of power," he adds.
A higher efficiency, laser-based approach would require far smaller satellites and transmitters, perhaps requiring just one launch, Hoffert notes. One proposal involves capturing sunlight in space via photovoltaics, converting the energy into a visible or an infrared laser and then beaming this concentrated light onto existing solar panel arrays in the desert around the clock. Weather can disrupt laser transmissions, however, and Hoffert says other technical hurdles remain for both microwave and laser light approaches.
The Japan Aerospace Exploration Agency (JAXA) is covering all bases as Scientific American magazine reported last year. JAXA hopes to have a one-gigawatt satellite in geostationary orbit around 2030 that may use either microwaves or lasers to send its energy back home.
Yet another school of thought involves placing solar-power generators and microwave transmitters on the surface of the moon, or even using a lunar base to construct the satellites before launching them (with relative ease, due to the moon's far weaker gravity) into a geostationary orbit. Many of the raw materials for crafting the satellites could be mined from the moon as well.
If these and other far-flung, future missions ever come to pass, their creators may look back on PG&E's faith this week in Solaren as a key moment in the history of SBSP development, Logan predicts. "If [Solaren] is able to deliver this energy, you're talking about the first time space-based resources have ever been imported to Earth," he says. "It's a significant breakthrough in the awareness of the fact that we're not limited to just the resources on the planet."
Auspiciousness aside, Solaren has a long road ahead of it in terms of raising capital and constructing the first-of-its-kind SBSP operation. Soothing local fears of death rays from space will also take some finessing, Logan admits.
In the end, PG&E has not invested its customers' or shareholders' finances in the deal, says Marshall, the company spokesperson; rather, Solaren is on the hook to deliver the power first. Over 15 years, Solaren has agreed to provide 200 megawatts of electricity almost continuously, enough for a quarter million homes, starting in June 2016.
"Even though PG&E took pains to assure the public they were not investing and that it was only a supply contract, it is still a big step," says CSP's Little. "If another energy supply contract is signed in the near future, I expect interest in space solar will really accelerate."
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39 Comments
Add CommentI've been studying this option of energy supply since 1975.
Reply | Report Abuse | Link to thisThe many nessesary parts of this system have been known since before 1972. However many have not been created or tested and the most important one, reliable,safe transport, is still not available.
We are talking about a project in high orbit that is hundreds of times larger and more complex then the international space station.
This is the long term solution to the humans energy needs, but I still don't see it as presently doable and I'm presently working on solving the transport problem.
Right now I would give this solar energy solution slightly better odds then plasma fusion over the next 50 years.
send solar panels in Space costs just 300-1000 TIMES more than deploy them in a desert, as explained in this “Space Solar Power hoax/illusion DEBUNKED” article:
Reply | Report Abuse | Link to thishttp://www.ghostnasa.com/posts/038sspdebunked.html
Ghostnasa is a pile of garbage. One guy who rants endlessly, with nary a care for things like facts or research, hardly constitutes a valid source of information.
Reply | Report Abuse | Link to thisI challenge the author of the website to an engineering duel. Bring your calculator.
Ignorant ape men are fearful of the sunsat at first, but they learn and eventually get down to business mining the moon for the materials to build large and very powerful radio-emitting black monoliths (see the NASA/DOE reference design). By doing so, they bring civilization to a new evolutionary plateau beyond the earth, and build new homes for the offspring of the industry. There is hope in the Kubrick-Clarke story, and it nestles nicely in other tradition.
Reply | Report Abuse | Link to thisIf ghostnasa's facts were off by an order of magnitude, it would still be silly to use space-based solar power. This is pie-in-the-sky fun stuff worthy of Discover or Popular Science magazines. In case anyone wants to know the simple fact: Space-based solar is less practical than millions of hamsters on treadmills.
Reply | Report Abuse | Link to thisThe problem is that ghostnasa's figures are off by several orders of magnitude. Let's assume the worst case and start off with 1000x more expensive. SBSP gets 10x more sunlight, and hence we're down to only 100x more expensive in watt terms. SBSP is almost maintenance free, unlike grown based solar, which needs regular cleaning due to weather effects. So, say, 50x now. It would require practical low cost space access, which would have definite spin-off applications. Another hard thing to estimate, but say we're down to 25x more expensive; once we take into account investment return from those. SBPS is a sellable export; like oil. Europe pays twice as much as the US, so that can be used to subsidise costs. So we're only about 15x more expensive now. Oh yes, and SBPS can provide BASELOAD ELECTRICAL CAPACITY on a 24/7/365 basis. Plug battery costs into the desert scheme and SBPS will probably end up costing slightly less.
Reply | Report Abuse | Link to thisAnd this is only initial costs. Another thirty years when the orbital stations are beginning to get clapped out, just recycle them on site. Since 90%+ of SBPS initial costs is launch, during their second lifetime, SBPS power costs 1/10th as much. Pay by the kWday?
A luckily there is no transmission loss and maintenance is easy...
Reply | Report Abuse | Link to thisHere is a reference on the safety and some comments.
Reply | Report Abuse | Link to thishttp://www.spaceenergy.com/i/pdf/safety_paper.pdf
SAFETY OF SPACE-BASED SOLAR POWER
Dr James Logan, NASA
Feb 2009
2.45 or 5.8 GHz 1 to 5 GW non-ionizing power.
(non-ionizing means not enough energy to ionize atoms or molecules)
Occupational limit 5mW/cm**2 General limit 1mW/cm**2
Beam size
Approx 2-4km wide.
Beam energy
Center 300 watt/m**2 or 30milliwatts/cm**2
(JKA: compare to 5milliwatts/cm**2 above)
Safety considerations
Except for maintenance personnel, human exposure
would not normally be permitted in these areas.
(JKA:But see size of beam above - 2-4km wide.
What about terrestrial animals - birds and bees he discusses not ground-living species.
How many cubic feet of concrete and armed guards are necessary to "not permit" human exposure?)
Microwave oven leak energy
1-5milliwats/cm**2 at 5 cm from any oven surface
How many "armed guards"? After 85% of the energy is harvested by dipoles above the ground, what's left to hit people or cattle below it at the center of the beam? 4.5 mW.
Reply | Report Abuse | Link to thisSpace satellites were hashed and rehashed in the 1970's people. The same stupid rants are being used against it now. You'd think the nation was still high on LSD and communes with teepees were in fashion as the nation's future.
Costs have been worked out in detail for over 3 decades, and they work. Mirrors concentrate solar power in orbit to raise efficiency. Rectennas can be made larger so the beam is less concentrated if absolutely necessary, but it isn't necessary.
Energy is primary to any economy. If you don't have energy available to use, you are poor. If you do, you aren't poor. Take a look around folks. We are not at the dawn of a new age of plenty on our present course.
By sparking a renewed public dialogue, PG&E makes a leadership investment in a vision of the future. This concept should be "on the table." So should a cost-benefit analysis of increased use of less carbon-intense fuels on Earth, such as nuclear energy. Space-to-Earth solar appears possible. It may not be a slam-dunk, and I do want an appropriate Environment Impact Statement performed. In the end, though the concept may be hard to engineer, I want our public dialogue to include "bold." The world is just as hungry for clean-energy, as it is for idea-leadership from our energy experts.
Reply | Report Abuse | Link to thisWhy would beaming energy from space that would not otherwise have reached Earth NOT contribute to global warming?
Reply | Report Abuse | Link to thisI agree with the poster that this issue is worthy of PopSci or Pop Mech. but not for a serious magazine such as Scientific American.This idea is akin the the global warming solutions involving "space shades" Keep this idea alive but spend the money on realistic options such as energy efficient living and business spaces powered by direct solar or geothermal. I know that these solutions don't sell as many magazines but they are very doable with the political will. When we have the human condition on earth in hand then pursue these extreme options. At this time these projects are just funding for the" military industrial complex" (sorry for the cliche).
Reply | Report Abuse | Link to thisWow, space-based solar would be a great boondoggle! Let's see, you have the cost of installation (huge), maintenance (high), ecological cost of production and booster pollution (high), ground station cost (still in the desert, so transmission costs are high), ground station environmental impact (high), ground station security costs. Then, assuming you can pull all that together, there's the issue of weather-variable path loss and solar flare susceptibility, plus a fail-safe command and control system - because pointing the beam off target would be a real hoot :-)
Reply | Report Abuse | Link to thisI think I would rather put my money into cold-fusion powered flying cars.
So true :-)
Reply | Report Abuse | Link to thisWow, space-based solar would be a great boondoggle! Let's see, you have the cost of installation (huge), maintenance (high), ecological cost of production and booster pollution (high), ground station cost (still in the desert, so transmission costs are high), ground station environmental impact (high), ground station security costs. Then, assuming you can pull all that together, there's the issue of weather-variable path loss and solar flare susceptibility, plus a fail-safe command and control system - because pointing the beam off target would be a real hoot :-)
Reply | Report Abuse | Link to thisI think I would rather put my money into cold-fusion powered flying cars.
Cold-fusion powered anything would be the better bet.
Reply | Report Abuse | Link to thisBut don't count out Public Graft and Extortsion co. they would be glad to attach this to their rate base.
It is beyond my imagination how this project even made it beyond the drawing boards. PG&E is trying to sell us an enormously expensive wasteful project to keep our energy grids centralized. It is a transfer of our energy dependence. If anyone wants to wipe out our grid, they could send a missile at it and we would be in the dark. Given the number of repair and maintenance missions sent to the ISS and Hubble, expect another regular stop along the way. We need a fundamental shift in our use and generation in electricity with focus on efficiency. Any energy expert would agree that efficiency is key. Any security expert would agree that a decentralized grid is ideal. 130 watts/sq ft hitting the surface of the Earth is more than enough energy to meet our needs. Our goal should be making solar panels easier to produce and more efficient. Our goal should be to improve our electrical storage systems. There have been more than enough stories here on SCIAM reflecting the research and discoveries supporting these ideals.
Reply | Report Abuse | Link to thisThe only leadership that is shown by energy conglomerates is to sustain the corporate structure not our energy needs. We have energy corporations buying up production runs of solar panels to make solar farms while our roofs do nothing but keep us in shade and rain off our heads. True leadership is one that focuses on the needs of the populace as a whole, not a select few. While all of you Occam's Razor agnostics pull out your calculators to determine if projects like this are viable, save yourself some time and take a look at the big picture. There is a fundamentally better solution and it is right under our noses.
It is beyond my imagination how this project even made it beyond the drawing boards. PG&E is trying to sell us an enormously expensive wasteful project to keep our energy grids centralized. It is a transfer of our energy dependence. If anyone wants to wipe out our grid, they could send a missile at it and we would be in the dark. Given the number of repair and maintenance missions sent to the ISS and Hubble, expect another regular stop along the way. We need a fundamental shift in our use and generation in electricity with focus on efficiency. Any energy expert would agree that efficiency is key. Any security expert would agree that a decentralized grid is ideal. 130 watts/sq ft hitting the surface of the Earth is more than enough energy to meet our needs. Our goal should be making solar panels easier to produce and more efficient. Our goal should be to improve our electrical storage systems. There have been more than enough stories here on SCIAM reflecting the research and discoveries supporting these ideals.
Reply | Report Abuse | Link to thisThe only leadership that is shown by energy conglomerates is to sustain the corporate structure not our energy needs. We have energy corporations buying up production runs of solar panels to make solar farms while our roofs do nothing but keep us in shade and rain off our heads. True leadership is one that focuses on the needs of the populace as a whole, not a select few. While all of you Occam's Razor agnostics pull out your calculators to determine if projects like this are viable, save yourself some time and take a look at the big picture. There is a fundamentally better solution and it is right under our noses.
Good grief! When I was at school, I was told that energy can be neither created nor destroyed - which would make "renewable energy" an oxymoron?
Reply | Report Abuse | Link to thisSolsats were a financially viable concept back when Gerard O'Neil and his students looked at them in 1978. The problem has always been that executives, and especially power company execs, have stupidly short-term outlooks, concentrating on the next quarter or perhaps the next year or two, because that's what their salary packages are based on. Solsats in 1977 were looking at 20-year payback times, much longer than the expected tenure of any energy company exec, so they were discarded out-of-hand.
Reply | Report Abuse | Link to thisGood luck to everyone involved in this project.
Did Peter Glaser have lunch with Stanley Kubrick and Arthur C. Clarke in 1967? I hope Pres. Obama gets the story. I hope he does the right thing.
Reply | Report Abuse | Link to thisThere are only two options that hold out the prospects of reasonably low cost energy at the scale needed to replace fossil energy, space based solar and nuclear fission. So unless another option opens up, for example fusion, then is one or the other. The do nothing alternative is population collapse to perhaps one or two billion people.
Reply | Report Abuse | Link to thisLike pgtruspace, I have been involved with power from space since 1975 (was one of the founders of the L5 Society). Solaren is trying to get around the high cost of space transport by making the power sats very light, over 10 kW/kg which would allow them to launch with present day rockets.
For the last 11 months a number of people have been looking into a proposal to boost a high performance ablation laser stage into space with a low performance chemical stage. The proposal is to combine the high efficiency of laser propulsion with the large unit payloads of rockets. This permits a relatively small fleet of 747 sized rockets and a modest (4GW) laser to support approximately million ton per year parts delivery pipeline to GEO. So far calculations point to a cost of~$100 per kg, some 200 times less than expendable rockets. At this transport cost we could build steam turbines in space.
If $100/kg to GEO can be realized, power at a penny a kWh and synthetic gasoline for $1/gallon seem possible.
www.htyp.org/dtc
Keith Henson
http://en.wikipedia.org/wiki/Keith_Henson
How can this be considered "pollution-free power [...] and without the emissions of fossil fuels?" How do they plan to get the panels into space? The only methods of launching anything into space that I am aware of involve an enormous amount of fossil fuel (rocket fuel). It seems like the energy involved in manufacturing the system (panels, microwave emitters), launching the materials into space, and launching people into space to build and maintain the system would be significant compared to the electricity output. For land-based PV, the energy requirement for the manufacturing alone takes a few years of operation to recoup. The whole lifecycle needs to be considered.
Reply | Report Abuse | Link to thisResponding to "thinkfirst", I worked out the energy payback time for lifting power sat parts to GEO. The payback, even for rockets was amazingly short, 100 days or less even for 5 kg/kW power sats. http://htyp.org/Hundred_dollars_a_kg/Note_1 This computation assumed making rocket fuel (hydrogen) out of water.
Reply | Report Abuse | Link to thisPower panels in space take a much shorter time to pay back the manufacturing energy as well because they get 6 times as much sunlight.
But it looks like steam turbines may be competitive with solar cells.
Re people in space, supporting 1000 space workers at GEO with 10kg/day would take about 1/2% of the construction material flow.
Keith Henson
Interesting, thanks.
Reply | Report Abuse | Link to thisAnother Junk-Science Scheme, like the Frankenstein Monster, comes back to life...
Reply | Report Abuse | Link to thisI began warning people, more than ten years ago, that the unscientific merger of CO2 hysteria with the desire for more renewable energy -- solar and windpower -- no matter how desirable, would have bad consequences for both the Earth's ecology, as well as for renewable energy. If you want to promote solar energy or wind-power, then do so on its own good merits -- lack of pollution, no payments for the energy, and so on. Recently we have seen calls by even Dr. Hanson of NOAA to increase the amount of particulates (soot?) into the atmosphere, to reduce solar energy input, all based upon the flawed CO2 theory of global warming -- which, by the way, isn't happening any more. But who cares! There's Free Money to be had from Washington, for all sorts of unproductive schemes.
Here, then, is yet more evidence of bad science being pushed into public policy, with predictably bad consequences. This scheme which comes from the pre-environmental days when atomic power was being pushed as being "too cheap to meter", cannot proceed without massive federal funding. Otherwise, the costs would be astoundingly high as compared to other power-generation methods.
A bad idea all around. And how about the body-core temperature rise predicted for animals and humans who wander into the "zapping zone"? This scheme was partly developed to make particle-beam weaponry, as you could turn the satellite to roast your enemy's cities. If this is to be classified as "clean energy" showing "leadership from our energy experts", then we are doomed.
Another Junk-Science Scheme, like the Frankenstein Monster, comes back to life...
Reply | Report Abuse | Link to thisI began warning people, more than ten years ago, that the unscientific merger of CO2 hysteria with the desire for more renewable energy -- solar and windpower -- no matter how desirable, would have bad consequences for both the Earth's ecology, as well as for renewable energy. If you want to promote solar energy or wind-power, then do so on its own good merits -- lack of pollution, no payments for the energy, and so on. Recently we have seen calls by even Dr. Hanson of NOAA to increase the amount of particulates (soot?) into the atmosphere, to reduce solar energy input, all based upon the flawed CO2 theory of global warming -- which, by the way, isn't happening any more. But who cares! There's Free Money to be had from Washington, for all sorts of unproductive schemes.
Here, then, is yet more evidence of bad science being pushed into public policy, with predictably bad consequences. This scheme which comes from the pre-environmental days when atomic power was being pushed as being "too cheap to meter", cannot proceed without massive federal funding. Otherwise, the costs would be astoundingly high as compared to other power-generation methods.
A bad idea all around. And how about the body-core temperature rise predicted for animals and humans who wander into the "zapping zone"? This scheme was partly developed to make particle-beam weaponry, as you could turn the satellite to roast your enemy's cities. If this is to be classified as "clean energy" showing "leadership from our energy experts", then we are doomed.
The novel Storm Killer published in 2008 depicts this same idea of a storm killing technology and describes how misuse of it can lead to disastrous consequences.
Reply | Report Abuse | Link to thisThe novel Storm Killer published in 2008 depicts this same idea of a storm killing technology and describes how misuse of it can lead to disastrous consequences.
Reply | Report Abuse | Link to thisHas anyone considered the effects of the atmosphere absorbing so much microwave energy? It may not seem like much at first, but if a lot of these things are built won't it start to add up? I realize this could meen less CO2 from fossil fuels.
Reply | Report Abuse | Link to thisThe entries on this subject are stunning. No one asks the key technical or commerical questions. Opinions are offered absent the inconvenience of fact based logic and without any detailed technical or commercial analysis. I suggest withholding judgement about Solaren until enough detail is available for complete technical and economic review.
Reply | Report Abuse | Link to thisThere are two military considerations to space-base proposals. One is to use the directed energy beam as a weapon which would primarily disrupt antenna arrays on the ground or in aircraft. The other consideration is that space-based power plants would be hard to defend against an enemy that wants to disrupt your economy by shutting down your power sources.
Reply | Report Abuse | Link to thisEverything in orbit around the Earth is vulnerable to space junk, which may or may not be on a random trajectory. It isn't that hard to deflect a piece of space junk and use it to take out a satellite of an adversary.
HAHAHA! I did a review of that book as a scoolwork 30 years ago! Nice to see it still relevant!
Reply | Report Abuse | Link to thisWell, this is the post i referred to in my previous comment, abt Stanley Kubrick- Arthur C Clarkes SF story.
Reply | Report Abuse | Link to thisThe danger is not in "death rays" but in causing thermo active columns of atmosphere between the transmitter and receiver on the earth.
Reply | Report Abuse | Link to thisMicrowaves of such frequency have an interaction with water molecules which causes them to be excited and become heated.
This interaction between microwaves and water vapor, especially rain clouds, has been known for decades and is demonstrated in the degradation and loss of satellite TV signals from orbit as well as microwave transmissions from point to point on earth.
So much for no negative effects on the biosphere.
Lunar Solar Power, as advocated by Dr. David Criswell, can be done with present technology, built in ten years, profitable in 15 years, at electric rates five to ten times less than existing cost. The PG&E rectennas are basically Dr. Criswell's concept.
Reply | Report Abuse | Link to thisSatellite based solar is not cost effective. The sheer number of required satellites in orbit is also physically unrealistic.
Nuclear isn't cost effective, either, when the cost to decommission facilities, and encase and store spent fuel is factored in.
Solar power via the moon is absolutely workable and cost-effective. I fail to see how any intelligent, reasonable person could ignore Dr. Criswell's proposal.
It is really bad that you are having a tough job on managing your emails, maybe you should have an assistant that will task to monitor all of your incoming emails. Thanks for http://www.ejaisolar.com/
Reply | Report Abuse | Link to thisas a long time supporter of space-based solar, i love the fact that somebody has finally started to push it seriously. unfortunately I simply cannot accept the beamed power approach - the difficulties of reliably keeping the beam centered are to my view even more dangerous than solid-core nuclear reactors (I am a firm supporter of Molten-Salt reactors however).
Reply | Report Abuse | Link to thiskeeping the topic on space solar, I am of the belief that space based solar would best be implemented along with an orbital elevator system. we are very close to having the materials capability, as carbon-fiber cables are finally being manufactured in significant length to be feasible in this application.
I beg to differ on your cost assessment, especially with regards to nuclear. while it may be applicable to existing solid-core reactors, it is completely irrelevant to the case of molten-salt based reactors such as the LFTR.
Reply | Report Abuse | Link to this