Solar Energy from Space

[Zergling]

Another problem with nuclear power is that there isn't that much uranium around, it would run into another shortage problem similar to fossil fuels.

I never thought electric cars were the best idea. Why wouldn't some form of alcohol work to replace gasoline? I think a car can be made to run on some kind of alcohol if I'm not mistaken. In fact, shouldn't any combustible fuel, even something like kerosene, work? I haven't formally studied Science, so I might be wrong. I think all we have to do is find another form of combustible fuel to replace oil.

Cars could also certainly be designed to run on any good burnable material that gave off a lot of energy, the issue is how easy the materials are to produce, and how much energy they can produce in cars compared to the energy it takes to make them.

 

[spirilis]

Another problem with nuclear power is that there isn't that much uranium around, it would run into another shortage problem similar to fossil fuels.

As I've understood it, that problem is a bit exaggerated. While it's true that uranium is in limited supply, the main issue here is that most (at least 99%) of uranium is the U-238 isotope, which is useless as a break-even fuel. HOWEVER, it can be converted into Plutonium (Pu-239) using a Fast Breeder Reactor which is fissile, and provides a net energy gain.

The Integral Fast Reactor I linked to earlier was a prototype design which involved a Fast Breeder Reactor located onsite next to a Plutonium nuclear power generation facility. As stated in the wikipedia article, an IFR reactor uses 99.5% of the source uranium for its power generation versus conventional light-water reactors, which only use 1% (since they can only run off the U-235 already present, and even that has to be enriched first).

Some more links:
Introduction to ANL's IFR Program

"Limitless" Fuel Supply
There is sufficient fuel to power IFR type facilities for well over 100 thousand years. This results because the IFR is a breeder reactor which can utilize uranium 238. Today's reactors only use uranium 235 which is less than 1% of the uranium found in nature. The IFR, with its fuel reprocessing capability, can use all the uranium. There is enough uranium that has been mined and placed in barrels (uranium 238) for IFR-type plants to provide all the electricity for the United States for over 500 years -- without mining. Also, the IFR can likely reprocess the spent fuel from today's reactors, and use the recovered materials for fuel. Uranium is as abundant in the earth as many of the commonly used materials such as bismuth, cadmium, mercury, silver, etc. In fact the uranium in a typical 1 ton block of granite (concentration of about 5 ppm) is the energy equivalent (if used in the IFR) of 10 tons of coal! The abundance of uranium suggests that its price will likely not increase as a fuel material for the foreseeable future.

more pages on that same site- Index of /designs/ifr

FRONTLINE: nuclear reaction: Dr. Charles Till has some insight on why the IFR project was canceled:

Q: Is the IFR still operating?

A: No. The IFR was canceled in the end of September of 1994, two years ago.

Q: Who made that decision?

A: The decision was made in the early weeks of the Clinton administration. It was tempered somewhat in the Department of Energy in that first year. Congress then acted to keep the program alive in that first year. And then in the second year of the Clinton administration, the decision to really reinforce the earlier decisions was made final, and the Administration put a very considerable effort into assuring successfully that the IFR would be canceled.

Q: And what was the basis for the decision to cancel the IFR? What grounds, what argument was presented?

A: The arguments fundamentally were that there was no longer any need for advanced nuclear power or research on nuclear power. In President Clinton's State of the Union address that first year, one of the statements was that unneeded programs would be canceled, and for example, programs on advanced nuclear power would be canceled. So that the fundamental argument was that there was no longer any need for any further research.

Q: Where does the IFR stand today?

A: Well, the IFR today is not an active program. The development of the IFR was carried on from 1984, then, to 1994. The work on the new fuel form and on the processes and on safety and so on, is all documented thoroughly in the literature, in the technical literature, so that the knowledge that was gained in those years is certainly there for others to study if they wish to do so. There is related work on the process, on the chemical processes, now being done at Argonne to help with some of the DOE nuclear waste. But it's not aimed at the IFR.

 

[Lateralus]

Another problem with nuclear power is that there isn't that much uranium around, it would run into another shortage problem similar to fossil fuels.

Is there a shortage? That's contrary to what I've read. I've read that current uranium supplies are low because demand is increasing so quickly. There are large amounts of uranium that are not economically viable to mine, right now, but will be once uranium prices reach a certain level.

Even if what you say is true, there are Breeder reactors.

Edit: Maybe I should delete my post after reading spirilis'.

Edit: Uranium/plutonium is not the only nuclear fuel being pursued, either. There's also thorium. This article seems overly optimistic, but the concept is interesting.

 

[spirilis]

I was actually thinking research should go into Nuclear development. I just don't know if we can get people to accept it because of all the fallout and radiation risks. People are so opposed to it, despite all the long term risks we take by remaining dependent on oil, that they don't even seem to see. How close are we to developing Fusion? In addition to being a good potential power source, it was my favorite power plant in SimCity 2000.

The nuclear fusion topic is another vast one, although I don't know that much about it yet as it's still a "non-mainstream" topic for the most part. Most of what I've read/watched/learned has to do with Dr. Robert Bussard's Polywell idea (Bussard died Sat. Oct 6, 2007 btw, but he left behind a team of researchers which should be well qualified to continue his work)

The 18 billion dollar question is, what's the deal with ITER and the whole donut-shaped Tokamak reactor project? According to Bussard, it is a tragic waste of time and money. He was instrumental in the project's creation, but he and other researchers didn't expect it to go far because it was known for a while that the idea was a wash. But it's become the government's brainchild, a high-budget project taken on a life of its own. I personally don't have much confidence that anything will come of it. But all of this is from listening to Bussard's opinion in his talk and interview, so I haven't checked this opinion with much fact yet.

Other researchers are working on spherical confinement systems (Inertial Electrostatic Confinement), where fusion is attempted by concentrating matter into a single point, using a globe-like confinement structure. Similar to a star, in other words--spherical in form. Makes sense huh? Bussard's Polywell concept works like this. Particularly attractive is his idea that using Boron and hydrogen can produce fusion with the option of collecting energy directly from electron transfer (much more efficient energy capture than using the resulting heat to operate a steam turbine as with conventional nuclear and fossil fuel power plants), and the end resulting waste is completely non-radioactive

Here's some links to Bussard's work. I highly recommend acquainting yourself with it and maybe searching through some more material. I haven't looked at some of the other ideas out there myself.

Dr. Robert Bussard - wikipedia page
Bussard's Google Tech Talk - Should Google Go Nuclear? Clean, cheap, nuclear power (no, really) (Too technical, makes my head spin, but the 2nd time watching it it made a little more sense...)
Bussard's last interview before he died - Dr. Robert Bussard's Fusion Breakthrough (Highly recommend listening to this if you have an hour to spare, it's a little less technical and a little more inspirational)
Polywell reactor - wikipedia page
Links to community resources about IEC fusion and Polywell concepts - Classical Values :: Dr. Robert W. Bussard Has Passed

Public/media awareness page created by one of the researchers: PolywellEnergy


ITER - wikipedia page

I am interested in researching more about the Tokamak project (mainly to check some of Bussard's negative claims against it) and other IEC-based projects out there. Bussard's Google Tech Talk got my interest piqued on the whole topic.

You know, I wonder what it would take to get into the energy industry. While I love IT work and it pays very well, some part of me finds excitement in learning about (and working with) energy, and I could imagine making a career out of it. I wonder how I could get my foot in the door, or where I could...

 

[ygolo]

I like what spirilis has posted. Clean, safe nuclear fuel is looking a lot more feasible to me now than earlier. At this point it seems to me like a good long term power alternative to fossil-fuels as well. I learned something. Thanks spirilis.

But I want to do two things in this post:

1. Debunk the idea that limited resources means we need to focus only on one form of energy solution.
2. Expand the conception of the Solar-Power-from-Space idea by systematically breaking the assumptions people seem to be making about it.

It is my firm belief that our future energy solutions should be fueled more by private enterprise, but that the gov’t can seed interest in particular areas. I think it should be more of an international effort than be seen as a prize for any one nation (though it is an attractive prize).

Towards point one above, I will ask a few rhetorical questions to get people thinking, and answer them with my own opinions...

• Why do we still continue to build varied types of power plants? From coal to oil burning, to hydro-electric, to wind-powered, to Nuclear, etc? I think the simple answer is that the needs and resources of particular are different, and that a different solution works out “best” in that local area and for the situation that needs to be dealt with. I hope to show that space based solar power has its niches as well.
• Why do we link most of our power sources to a power-grid? I think the simple reason is for robustness and flexibility in where we get power. Power transmission from space is of the way space power is linked to terrestrial power.--a way to expand the power grid to space. Electro-magnetic signals carry with it electromagnetic power. We are already, in a sense, beaming energy from space. The energy can be localized to particular frequencies so that only certain objects are able to pick it up. The principles behind radio transmission are essentially the same as that for power transmission (In fact some of the early patents of radio technology were actually towards wireless power transmission).
  In the case of microwave transmission at the current proposed frequency (least atmospheric loss) would require a transmitter 1 km in diameter and a receiver 10km in diameter. I am not sure what the loss is. I have seen 85% power efficiency quoted, but that was under (unrealistically?) optimistic conditions.

I don’t think the first point takes very much to prove, any technology that can potentially pay for its own research will attract venture capitalists and entrepreneurs who take those risks. So I think I need to focus on point 2, to show how space solar power can fit into this category.

So on to breaking the assumptions (keep in mind, we are talking half-century long time frames or more before the power being useful on Earth)....

• The initial aim of Space Solar power need not be to replace terrestrial power:
  In fact, solar power seems to be a rather popular power source in space. (satellites, rovers, international space station, etc). I think solar power fits this niche very well. Just as windmills fit the niche in very windy areas, and geothermal is great in areas that can take advantage of it.
  • Can we help power the international space station with even more Solar panels? Will this ever give us excess power that may be used on earth?
  • Can we create a space level power grid to which new satellites can link to with small shortwave rectennas (or laser based technology) instead of (in addition to) it’s own solar panels? Under what conditions would the ROI on this be warranted? Also, if such a power-grid (I am thinking wireless) were made, would there ever be excess energy created from the power network. Enough excess energy to warrant beaming it back to Earth for collection?
  • Could we create a central energy bank on the moon or mars for all future missions on those celestial bodies (whether in the form microwave receivers or solar panels, or whatever)? Especially on the moon (of which, we always see one side), could excess energy be beamed back to Earth?
• We need not launch all the solar panels from Earth If we believe that a 20km^2 array generates 500MW on Earth. Then moon-dust based solar panels that is 20km^2 will generate 5MW based on current estimates. Is this enough, to create a self-sustaining mini-household on the moon? How much power would it take to power machinery to collect materials and build a solar array on the moon surface itself?
• In a fault tolerant system we don’t really need to go out and fix broken panels We just let it go. Besides, a good number of satellites already run on solar power and the space-junk problem is not prohibitive. Modern satellites have about 32000 solar cells that provide about 520 W. Is it possible that these satellites, already in use for different purposes may have excess power at times? Is this reason enough to create a space power grid? It seems like GPS, TV, and communication satellites could benefit from having a power grid to plug into.

In sum, I think the choice of solar power in space is a natural one. The choice to link-up varying and fickle sources of power in a grid to share power is a natural choice. I think it will eventually make sense to connect the earth and space power grids. And, if no other renewable, clean source is found by the time we collectively realize a crisis in energy(I consider this likely), then we will try to tap the resource that has the fewest limitations (and I think at that time, building out the space power grid is what will make sense).

I hope if nothing else, this has changed the way people look at Space solar power. If I had more time, this would be less a rant, and would contain more sources. But I have been rather busy.

You know, I wonder what it would take to get into the energy industry. While I love IT work and it pays very well, some part of me finds excitement in learning about (and working with) energy, and I could imagine making a career out of it. I wonder how I could get my foot in the door, or where I could...

I know what you mean. I am learning a bit of the RF/microwve stuff now. It would be interesting if they are targeted towards transmitting power for a change, and would pose a whole new set of technical challenges.

 

[spirilis]

I do like the idea of a space-based power grid for space-bound applications, and thinking further into the future, to a day when we have such a rich presence in outer space that it becomes appropriate, beaming power to the planet may be an attractive option. I still see that as a very long-term extension of that technology, not its principle use. Beaming power to other satellites and other orbiting platforms is a great idea though.

Or going the other way around--focused lasers beaming power from the planet to the orbital power grid would be a great way to supplement an orbital energy crisis, should we ever have moon or orbital communities suffer from an unexpected failure of their orbital power systems.

 

[iwakar]

Space Elevator

Space Elevator

"Engineers hope the elevator will transport people and objects into space, and there have even been suggestions that it could be used to dispose of nuclear waste. Another proposed idea is to use the elevator to place solar panels in space to provide power for homes on Earth."

 

[ygolo]

We had this discussion about a year and some ago.

There have been several developments since--both on the polywell nuclear fission concept (which was brought to my attention in this thread by Spirilis) and for the Space Based Solar Power (SBSP) concept.

The main point I was trying to make (and I was less articulate back then) was that there is no "one-size-fits-all" solution to the energy problem and that SBSP was one viable solution that I believed we'd see some time in the future.

SBSP was met with heavy skepticism. But news from earlier this month shows SBSP is a very real possibility (we find out by October, just how real).

Worldchanging: Bright Green: Solar Into Space

Also, check out spirilis links, there has been some updates to the polywell nuclear fusion concept as well. Check out, especially, what happened in Fiscal Year 2008 and Fiscal Year 2009.

 

[INTJ123]

when are you people going to get over solar cells, solar power is great but solar cells run at around 10 - 20% efficiency, they cost a lot, and reduce efficiency when heat soaked. We need to come up with new ways to harness the energy. There are now systems that are twice as efficient running around 30%. Also look up sunflower project for a new type of cost efficient solar cell system, they use mirrors (which are cheaper) in a parabolic fashion, to concentrate the light to one focal point on a special solar cell that can handle higher amounts of heat I'm guessing.

 

[spirilis]

We had this discussion about a year and some ago.

There have been several developments since--both on the polywell nuclear fission concept (which was brought to my attention in this thread by Spirilis) and for the Space Based Solar Power (SBSP) concept.

The main point I was trying to make (and I was less articulate back then) was that there is no "one-size-fits-all" solution to the energy problem and that SBSP was one viable solution that I believed we'd see some time in the future.

SBSP was met with heavy skepticism. But news from earlier this month shows SBSP is a very real possibility (we find out by October, just how real).

Worldchanging: Bright Green: Solar Into Space

Also, check out spirilis links, there has been some updates to the polywell nuclear fusion concept as well. Check out, especially, what happened in Fiscal Year 2008 and Fiscal Year 2009.

Wow thanks for reminding me about the polywell project. From what I've read it seems things are at a standstill, as they've been receiving life support funding for the most part -- Polywell - Wikipedia, the free encyclopedia

Still hope things move forward soon.

 

[Octarine]

This technology has always amused me, ever since I first heard about it (I actually think it was the old Simcity LOL).

I am curious as to how your thoughts have changed over time.

I'm still with Ptgatsby on this particular technology. At the moment, I'm not convinced it is going to be cost effective. I know power generation technology traditionally discusses concepts like efficiency and power density, but how important are these factors really? Given the huge amount of solar energy that falls on the earth, we don't actually need such efficiency, unless we want to sustain very high populations (upwards of 200 billion by my crude estimates).

In terms of solar, I am increasingly interested in the claims (cost effectiveness) made about solar thermal.
http://en.wikipedia.org/wiki/Solar_thermal_energy
Of course I know a few people working on solar cell technology too, but I see that more applicable to distributed applications.

Yes, the manufacture of one solar panel will cost more than the manufacture of many, generally speaking (though at the scales we're talking about, even that is probably not true. There are reasons why silicon wafers aren't giant, you know.)

Either way, the rocketry aspect is a major cost, along with maintenance. (how fragile is this technology vs space debris?)

Who says we have to replace current coal or Nuclear power plants?

And a few years later, we have the Fukushima disaster and carbon taxes being implemented. The result is certain governments planning the phase out of nuclear and coal power generation.

Of course I don't see these technologies going away in the near future, considering the projected energy demands with the substantial economic growth projected into the future.

What place do people see for these alternative technologies (including fission) in the intermediate future?

 

[ygolo]

You may be surprised to learn that my thoughts haven't really changed that much on this subject. But I can see all the communication mishaps we had, that lead, essentially, to ptgatsby and me talking around each other. I was thinking big picture, and he was thinking from the perspective of an individual making an investment decission.

The basic points I was making were more economic than scientific. I'll see if I can be more articulate this time.

1) Investment in research (or risk ladden investment of any type) is not (and should never be) an "all eggs in one basket" type of investment. I was not saying, "pump all your money into this idea", because I would not say that about any idea. But I believe it is an idea that is inevetable based of the the trajectory of human history.

2) I was thinking really long term (almost in "forever" terms). At some point, human beings will run out of land on Earth. Transmission of power through space and atmosphere become imperitives at that point in human history. At some point much earlier than that, space "real-estate" will be cheaper than real-estate on Earth. Keep in mind we need land to generate our food, and to live on, not just for our energy. Deep Sea terraforming may help with that, but even that is limited (in "forever" terms).

3) Also, in "forever" terms, space travel must become cost effective for many applications, including terraforming celestial bodies for food or living purposes. The launch cost problem needs to be researched in general, not just for this application. Even more practical things like communication systems can benefit from cheaper launch costs. Space elevators, slow/multi-stage launches, etc. are being investigated.

4) In engineering, Big Projects lead to Big Failures. Things happen "organically" with far more success, even though the "organic" growth ends up costing more over all. The way I envisioned the development of this technology was:
a) Satellites for use in other applications, start hooking up to a power grid in space.
b) Instead of decomissioning satellites, we power down most of it, and use the solar panels on it to feed into the grid.
c) The Earth and space power grids, link up

I was making one scientific/technological point (perhaps not very well):
1) LASER and microwave transmission of power has far less loss than the incoherent, and non-directional light from the sun.

----
As far as my comment about replacing current coal or Nuclear power plants...that was poor wording on my part. What I meant was that the technology in question would be part of human history at some point, not necessarily at the point we are at now.

----
The main thing that has changed, is that I am a lot more pro-nuclear than I used to be. Near term, I think, next generation nuclear technology (like traveling wave or thorium reactors) needs to be a big part of the energy mix. Again, there is no one-size-fits-all solution to these things.

 

[Octarine]

2) I was thinking really long term (almost in "forever" terms). At some point, human beings will run out of land on Earth. Transmission of power through space and atmosphere become imperitives at that point in human history. At some point much earlier than that, space "real-estate" will be cheaper than real-estate on Earth. Keep in mind we need land to generate our food, and to live on, not just for our energy. Deep Sea terraforming may help with that, but even that is limited (in "forever" terms).

Ah, OK, I get it in terms of not covering the whole tropics with solar electricity generation. There is always the question of what you are taking away when you divert a resource. Widespread solar capture It makes me wonder about the effects on ground life and effects on albedo etc.
In principle though, how much more useful energy could be gained from space based solar collection compared with collection on the ground? You still have to deal with transmission and re-collection through the atmosphere, but it can be captured for longer periods of time than the day cycle. And as you said, laser/microwave transmission of power has less loss through the atmosphere.

As far as my comment about replacing current coal or Nuclear power plants...that was poor wording on my part. What I meant was that the technology in question would be part of human history at some point, not necessarily at the point we are at now.

Ok. I still see it as at least 75 years away before it could become widespread, but that is just a crude prediction.