Is Rocketing Nuclear Waste into the Sun a Viable Solution?

[Astronuc]

Does uranium or plutonium or radium pose a risk in its natural state, say if you camp on top of it over night?

Plutonium has such a relatively short half-life in terms of the age of the earth, that one does not find it readily in the environment. Uranium is naturally occurring in granite and certain areas, as it thorium. Radium is a daughter product in the decay chains of U and Th, and is present in trace quantities.

http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radser.html

Camping overnight on top of a geological (natural) deposit of U (with trace of Pu) is not harmful.

When using Ra-226/228 in a lab, it is shielded as are all radionuclides. It is a matter of using the appropriate shielding and procedures when dealing with radioactive material.

 

[vanesch]

Thanks Azael. The migration factor was something I had no idea about. What springs to mind every time are these 3 mile Island and Chernobyl scenarios.

This has been discussed already in a few threads, but you have to know that at Three Miles Island, nothing seriously happened externally, and that there was still a very long way for 3 Miles Island to turn into something that even remotely would resemble Chernobyl.

At 3-miles island, what happened was that the operators got into panic mode on a minor error, took about every wrong decision that they could for about 6 hours, emptied by error part of the (shut-down) reactor vessel from its cooling water, and hence, part of the fuel which was still producing decay heat, melted, until people got wiser, started pumping in water again, and cooled down the whole business again. In the whole operation, nor the reactor vessel, nor the containment building has at any moment been put in danger. So containment of most of the radioactivity was, at any moment, secure. The only radioactivity that was released was on purpose: the steam that was produced when people pumped in water again. They evaluated the potential risk, decided that it was below the specified norms, and proceeded. NOBODY got a dose over the legally specified maximum dose in this "terrible accident".

So 3-miles island proved that you could do the most stupid things with a reactor for about 6 hours, and that still nobody got hurt (but that you damaged the installation). Try that with a car In other words, 3-miles island proved in fact the enormous SAFETY of the design of a western nuclear power plant. And things got much much better since then.

Chernobyl is the opposite. Chernobyl is the illustration that if you REALLY want to cause a disaster in nuclear technology, you have to start with a BAD DESIGN, and not provide any build-in safety. Next, you need to have totally incompetent, reckless idiots steering the plant and ask them to do a stupid experiment. And even if you do that, it will take you some time before things go wrong, because although Chernobyl went wrong, ONE HAD ALREADY DONE a similar experiment elsewhere, but it didn't go (too) wrong. And then you need clueless officials who don't do anything sensible for the first 36 hours after the accident.

The Chernobyl reactor was a bad design (and that was WELL-KNOWN), in that the reactor was inherently instable, and didn't have any passive shut-down mechanism (as has every western reactor). It didn't have any automatic security system either, that shuts down the reactor when operation parameters get in the red. It wasn't build in a pressure vessel, and it wasn't build in a containment building: the building had WINDOWS.
There were no safeguards on stupid operator commands, such as pulling out the control rods beyond their limit.

One single of these measures would have been sufficient to avoid the accident.

So what happened in short is that the operators of the night crew, who didn't have any experience with a nuke (they were used to a coal plant), wanted to do the experiment, made an error which made the reactor almost shut down. Because they wanted to avoid by all means that it stopped (as this would prevent them doing the experiment, and probably get their ears washed in the morning), they did a series of incredibly dangerous things (such as pulling out all safety bars beyond their limits, pumping in too much water etc...). Because of the unstable and unsafe design, the reactor finally did what they wanted, namely diverge again, but as there was no build-in stop to the power, it climbed to several tens of times its nominal power in a few seconds and hence got incredibly hot in a very short time.
Because there was no pressure vessel, the thing underwent a steam explosion, and because there was no containment building, well, it blew essentially up in the open.
Because there was no passive safety, the reactor didn't shut down! It continued to produce heat, and hence the graphite caught fire. So we had a WORKING reactor, producing heat, in the mid of a coal fire, in the open, full of radioactive elements (fission products, and military stuff to be irradiated), which rose of course in the convection of hot air.

So what did they do ? They called the fire brigade, and didn't tell them it was the reactor that was on fire!
It was only THE NEXT DAY that one realized what happened, and that boron was dropped (with helicopters) on the reactor to STOP it from working.
Only 36 hours after the explosion, one started to evacuate the nearby town.

Now, in as much as this was a true disaster, the world didn't disappear. It was of the same order of magnitude as other disasters that humanity sometimes faces.

The whole course of events, from the start to the end, is totally unthinkable in a western power plant. It is what you get when there is incompetence and recklessness on all levels, from the design, to the operation, to the crisis management.

 

[Azael]

I think it is an extremely dangerous PR game, because there are many chances that the COMPLETE burnup of all actinides will prove industrially impossible or economically a disaster. Maybe not, but there are serious chances that it will be.

As such, then the argument is perfect: "they finally admitted that they didn't know what to do with the waste, they promised they could burn it, and now it is clear that they can't".

Hmm yeah I se your point, offcourse there will never be 100% burnup of all actinides. But if they can be reduced to a level that the need for a 100 000 years repository is eliminated its enough. I guess some amount of actinides can be burried with the fissions products and still not be a threat after the 500-1000 years that is needed for fp's to decay? Aslong as the waste after 1000 years have a activity close to the activity of uranium ore. A repository will be needed for the fp's regardless.

But id say that if we can not get atleast 99% burnup of the minor actinides we should drop the uranium fuel cycle completely and follow the same plan as India, a future with several thousand reactors all producing waste at the same ammounts/kWh as todays is unacceptable in the long term.

 

[vanesch]

But id say that if we can not get atleast 99% burnup of the minor actinides we should drop the uranium fuel cycle completely and follow the same plan as India, a future with several thousand reactors all producing waste at the same ammounts/kWh as todays is unacceptable in the long term.

Sure, the idea is to switch to fast breeders, no ? The current cycle is not only producing annoying waste, it is especially wasteful with ressources!

 

[baywax]

Sure, the idea is to switch to fast breeders, no ? The current cycle is not only producing annoying waste, it is especially wasteful with ressources!

This may not be completely related to the thread but, why isn't there more research into the Hydrogen Fuel Cell generators (like the ones being used for individual households in Japan)? This would certainly reduce the waste of resources and the waste disposal issue.
They were using the Fuel Cell on the Apollo missions (40+ years ago), there must have been some advancements with them by now.

 

[vanesch]

This may not be completely related to the thread but, why isn't there more research into the Hydrogen Fuel Cell generators (like the ones being used for individual households in Japan)? This would certainly reduce the waste of resources and the waste disposal issue.
They were using the Fuel Cell on the Apollo missions (40+ years ago), there must have been some advancements with them by now.

As far as I understand, hydrogen fuel cells use a catalytic process to combine hydrogen and oxygen into water, producing electricity. But the fuel for these cells is hydrogen, which can, for instance, be obtained by electrolysis of water.
So it is a kind of battery.

 

[baywax]

As far as I understand, hydrogen fuel cells use a catalytic process to combine hydrogen and oxygen into water, producing electricity. But the fuel for these cells is hydrogen, which can, for instance, be obtained by electrolysis of water.
So it is a kind of battery.

These things have been around since the 1800s. For some rea$on, they've been kept way on the back burner.

There are several different types of fuel cells, each using a different chemistry. Fuel cells are usually classified by their operating temperature and the type of electrolyte they use. Some types of fuel cells work well for use in stationary power generation plants. Others may be useful for small portable applications or for powering cars. The main types of fuel cells include:

Polymer exchange membrane fuel cell (PEMFC)
The Department of Energy (DOE) is focusing on the PEMFC as the most likely candidate for transportation applications. The PEMFC has a high power density and a relatively low operating temperature (ranging from 60 to 80 degrees Celsius, or 140 to 176 degrees Fahrenheit). The low operating temperature means that it doesn't take very long for the fuel cell to warm up and begin generating electricity. We’ll take a closer look at the PEMFC in the next section.

Solid oxide fuel cell (SOFC)
These fuel cells are best suited for large-scale stationary power generators that could provide electricity for factories or towns. This type of fuel cell operates at very high temperatures (between 700 and 1,000 degrees Celsius). This high temperature makes reliability a problem, because parts of the fuel cell can break down after cycling on and off repeatedly. However, solid oxide fuel cells are very stable when in continuous use. In fact, the SOFC has demonstrated the longest operating life of any fuel cell under certain operating conditions. The high temperature also has an advantage: the steam produced by the fuel cell can be channeled into turbines to generate more electricity. This process is called co-generation of heat and power (CHP) and it improves the overall efficiency of the system.

Alkaline fuel cell (AFC)
This is one of the oldest designs for fuel cells; the United States space program has used them since the 1960s. The AFC is very susceptible to contamination, so it requires pure hydrogen and oxygen. It is also very expensive, so this type of fuel cell is unlikely to be commercialized.

Molten-carbonate fuel cell (MCFC)
Like the SOFC, these fuel cells are also best suited for large stationary power generators. They operate at 600 degrees Celsius, so they can generate steam that can be used to generate more power. They have a lower operating temperature than solid oxide fuel cells, which means they don't need such exotic materials. This makes the design a little less expensive.

Phosphoric-acid fuel cell (PAFC)
The phosphoric-acid fuel cell has potential for use in small stationary power-generation systems. It operates at a higher temperature than polymer exchange membrane fuel cells, so it has a longer warm-up time. This makes it unsuitable for use in cars.

Direct-methanol fuel cell (DMFC)
Methanol fuel cells are comparable to a PEMFC in regards to operating temperature, but are not as efficient. Also, the DMFC requires a relatively large amount of platinum to act as a catalyst, which makes these fuel cells expensive.

http://auto.howstuffworks.com/fuel-cell1.htm

 

[vanesch]

These things have been around since the 1800s. For some rea$on, they've been kept way on the back burner.

Yes, but don't go thinking that they are a *source* of power. They are, as I said, a kind of battery: they can give back (part of the) electricity that you consumed to make the hydrogen.

 

[Azael]

Sure, the idea is to switch to fast breeders, no ? The current cycle is not only producing annoying waste, it is especially wasteful with ressources!

Hopefully, but if the current prospecting cycle finds a lot of cheap uranium, like it probably will, I think that will put a big dent in the nuclear industries motivation to go towards fast breeders.

 

[baywax]

Yes, but don't go thinking that they are a *source* of power. They are, as I said, a kind of battery: they can give back (part of the) electricity that you consumed to make the hydrogen.

I'm only mentioning the FC technology as one way to reduce or eliminate nuclear waste. Thank you vanesch.

 

[vanesch]

I'm only mentioning the FC technology as one way to reduce or eliminate nuclear waste. Thank you vanesch.

In what way would they reduce nuclear waste ??

 

[CaptainQuasar]

In what way would they reduce nuclear waste ??

I think he means they would reduce nuclear waste if we used some non-nuclear method of generating power to produce hydrogen, then stored and transported power in fuel cells maybe?

But baywax, the thing is, every way we currently have to produce the hydrogen for fuel cells consumes more energy from conventional sources (like nuclear reactors that produce electricity) than ever comes out of the fuel cell. So fuel cells at the moment aren't a solution to the same problem that nuclear power is; nuclear power is for generating energy and fuel cells are for storing energy, as vanesch said they're like batteries. Using fuel cells wouldn't have any effect on whether nuclear waste is produced in generating energy.

Theoretically, if we could find or bioengineer something like bacteria or algae that produce large quantities of hydrogen as a byproduct, and they didn't take too much conventional energy to cultivate, we could maybe get fuel cells and other parts of a hydrogen economy working. But I don't think there's any technology like that even on the horizon.

⚛​

 

[baywax]

I think he means they would reduce nuclear waste if we used some non-nuclear method of generating power to produce hydrogen, then stored and transported power in fuel cells maybe?

But baywax, the thing is, every way we currently have to produce the hydrogen for fuel cells consumes more energy from conventional sources (like nuclear reactors that produce electricity) than ever comes out of the fuel cell. So fuel cells at the moment aren't a solution to the same problem that nuclear power is; nuclear power is for generating energy and fuel cells are for storing energy, as vanesch said they're like batteries. Using fuel cells wouldn't have any effect on whether nuclear waste is produced in generating energy.

Theoretically, if we could find or bioengineer something like bacteria or algae that produce large quantities of hydrogen as a byproduct, and they didn't take too much conventional energy to cultivate, we could maybe get fuel cells and other parts of a hydrogen economy working. But I don't think there's any technology like that even on the horizon.

⚛​

That's right Capt. Q, less emphasis on Nuclear Power as a source of energy would reduce nuclear waste.

As for hydrogen production, solar power is a "free" source of energy, wind and hydro are as well. What's more is the fact that we tend to make leaps in technological discoveries and this is one area where we can use a few. Remember that most computers used to need a warehouse to contain them and that your mobile phone used to be the size of an AK7. I have the feeling that there is an efficient and cheap method of hydrogen extraction just waiting to make someone a lot of money.

Sorry to get off the topic, inadvertently. I am particularly interested in the safe mining and storage of nuclear material since I was one of many who helped to instill a 28 year long moratorium on uranium mining in my province.

 

[Azael]

Uranium is already mined safetly and to high environmental standards in Australia and Canada. Its really no worse than other kinds of mining.

There is one simple thing that limits solar power that no technology can change. Its incredibly diluted. About 1000 watts/m^2 at the best of conditions around the equator. The intermittens means its only producing a third of that on average. So you need 3 square kilometers of solar panels to produce the same amount of energy as a average sized reactor. That is assuming if they are in sahara and have 100% energy conversion. In reality we are talking anything from 10-300 square kilometers depending on location in the world and efficiency of the conversion.

Now consider that solar panels require exotic metalls like germanium, Tellurium ect that offcourse need to be mined, mining those have in general a larger environmental impact than mining uranium because of less concetration in the ore. Factor that in and solar power isn't all that environmental, especially not considering the need for a backup because of its intermitten nature.

Solar power is no more "free" than uranium is "free".

Wave power however has a huge potential, wind perhaps as well but the experience so far from denmark and germany isn't very encouraging. But the environmental impact of nuclear power is already as small as the impact from vind and hydro. With closed fuel cycles the environmental impact would further be reduced by orders of magnitude.

 

[CaptainQuasar]

As for hydrogen production, solar power is a "free" source of energy, wind and hydro are as well. What's more is the fact that we tend to make leaps in technological discoveries and this is one area where we can use a few. Remember that most computers used to need a warehouse to contain them and that your mobile phone used to be the size of an AK7. I have the feeling that there is an efficient and cheap method of hydrogen extraction just waiting to make someone a lot of money.

Well, yes, it's possible. But nuclear power is here now and switching to building nuclear plants instead of coal-fired or oil-fired plants would confer immediate environmental benefits. If you would depend on a nebulous possibility that we might, some day, achieve an efficient and cheap method of hydrogen production, why not depend on a bet that we're going to find a cheap, efficient solution to nuclear waste at some point in the future?

Sorry to get off the topic, inadvertently. I am particularly interested in the safe mining and storage of nuclear material since I was one of many who helped to instill a 28 year long moratorium on uranium mining in my province.

I sympathize in some ways with people who oppose the construction of nuclear reactors - but it doesn't make any sense to me at all why someone would oppose the mining of uranium. I mean… isn't mining uranium basically the same thing as cleaning up nuclear waste that's freely present in the environment and containing it?

And even besides that… surely coal or oil or whatever else is used to produce power, instead of nuclear reactors, wherever you live is just as environmentally damaging, if not more so to mine compared to uranium?

What was the perceived benefit of prohibiting uranium mining? A moratorium actually seems like it might benefit whoever held the mineral rights, if it defers mining to a point in the future where uranium is more scarce on the world market.

⚛​

 

[baywax]

Well, yes, it's possible. But nuclear power is here now and switching to building nuclear plants instead of coal-fired or oil-fired plants would confer immediate environmental benefits. If you would depend on a nebulous possibility that we might, some day, achieve an efficient and cheap method of hydrogen production, why not depend on a bet that we're going to find a cheap, efficient solution to nuclear waste at some point in the future?



I sympathize in some ways with people who oppose the construction of nuclear reactors - but it doesn't make any sense to me at all why someone would oppose the mining of uranium. I mean… isn't mining uranium basically the same thing as cleaning up nuclear waste that's freely present in the environment and containing it?

And even besides that… surely coal or oil or whatever else is used to produce power, instead of nuclear reactors, wherever you live is just as environmentally damaging, if not more so to mine compared to uranium?

What was the perceived benefit of prohibiting uranium mining? A moratorium actually seems like it might benefit whoever held the mineral rights, if it defers mining to a point in the future where uranium is more scarce on the world market.

⚛​

All valid points. The moratorium was about how the tailings from the uranium mine might pose a problem to people who like to drink water in the area.

I think any mining today beats the mess created by tar sands oil extraction.

 

[baywax]

Uranium is already mined safetly and to high environmental standards in Australia and Canada. Its really no worse than other kinds of mining.

There is one simple thing that limits solar power that no technology can change. Its incredibly diluted. About 1000 watts/m^2 at the best of conditions around the equator. The intermittens means its only producing a third of that on average. So you need 3 square kilometers of solar panels to produce the same amount of energy as a average sized reactor. That is assuming if they are in sahara and have 100% energy conversion. In reality we are talking anything from 10-300 square kilometers depending on location in the world and efficiency of the conversion.

Now consider that solar panels require exotic metalls like germanium, Tellurium ect that offcourse need to be mined, mining those have in general a larger environmental impact than mining uranium because of less concetration in the ore. Factor that in and solar power isn't all that environmental, especially not considering the need for a backup because of its intermitten nature.

Solar power is no more "free" than uranium is "free".

Wave power however has a huge potential, wind perhaps as well but the experience so far from denmark and germany isn't very encouraging. But the environmental impact of nuclear power is already as small as the impact from vind and hydro. With closed fuel cycles the environmental impact would further be reduced by orders of magnitude.

Yes the extraction methods such as using acids or arsenic are not good. These tailings can damage major areas of wilderness and populated areas as well. You are making a very squeaky clean image of Nuclear power especially calling it less damaging than hydro. I'm trying to remember a whole town like Chernobyl being irradiated and wiped out by a hydro dam. I suppose the technology has come quite a ways since then. But, its not the technology at fault here, its the people using it and their lack of attention to details like those found in environmental issues.

 

[CaptainQuasar]

You are making a very squeaky clean image of Nuclear power especially calling it less damaging than hydro. I'm trying to remember a whole town like Chernobyl being irradiated and wiped out by a hydro dam.

It sounds like you're Canadian. Did you read the CANDU report about Chernobyl? I think http://canteach.candu.org/library/19910101.pdf" . (I live in the U.S. but that happens to be the first engineering report I read about Chernobyl.) It was a seriously careless reactor design.

Do you know how many Soviet space missions simply blew up on the launch pad? They had some major accomplishments but they took a kind of trial-and-error approach to engineering. From what I've read about when they started trying to manufacture their own microprocessors in the 1970's, each chip would get shipped with a list of instructions that didn't work because the manufacturing tolerances were so poor - almost every processor was unique. Whoever received the chip and built a computer around it would have to rewrite all of their software to avoid using the faulty instructions. Eventually they just gave up and started importing Western hardware.

You might know that while U.S. ICBMs are armed with a single high-yield warhead, Soviet/Russian missiles have a large number of smaller warheads. They had to do this because a fair number of the warheads were duds and if they only used one they couldn't be sure it would detonate.

I wouldn't say that nuclear power is squeaky clean but with hydro entire towns get wiped out just building a hydro dam. Way more than that, in fact - The Three Gorges dam which will be the largest in the world is going to http://en.wikipedia.org/wiki/Three_Gorges_Reservoir_Region" (and of course drown forests and a variety of other habitats.)

⚛​

 

[Azael]

Yes the extraction methods such as using acids or arsenic are not good. These tailings can damage major areas of wilderness and populated areas as well. You are making a very squeaky clean image of Nuclear power especially calling it less damaging than hydro. I'm trying to remember a whole town like Chernobyl being irradiated and wiped out by a hydro dam. I suppose the technology has come quite a ways since then. But, its not the technology at fault here, its the people using it and their lack of attention to details like those found in environmental issues.

Well there are hydro accidents that are worse than Chernobyl. Google for Banqiao Dam disaster, by far the worst industrial accident ever. Close to 200 000 deaths, 6 million buildings destroyed and 11 million people affected.

Tailings "can" damage large areas, but if mining is done correctly Like in Australia and Canada it doesnt. Mining done in any western country has to live up to stringent environmental laws.

Plenty of life cycle assesments have been made for different energy source and nuclear is every bit as good as wind and hydro and its better than solar and biomass. If you got acess to peer review journals take a look at these two articles.

Mark A.J. Huijbregts et al, ECOLOGICAL ECONOMICS, 64 (2008), 798–807
M Rashad, Applied Energy, 65 (2000), 211-219.

ExternE is also very interesting to look at and everything is published on externe's homepage
www.externe.info

 

[mheslep]

...There is one simple thing that limits solar power that no technology can change. Its incredibly diluted. About 1000 watts/m^2 at the best of conditions around the equator. The intermittens means its only producing a third of that on average. So you need 3 square kilometers of solar panels to produce the same amount of energy as a average sized reactor. That is assuming if they are in sahara and have 100% energy conversion. In reality we are talking anything from 10-300 square kilometers depending on location in the world and efficiency of the conversion.

Now consider that solar panels require exotic metalls like germanium, Tellurium ect that offcourse need to be mined, mining those have in general a larger environmental impact than mining uranium because of less concetration in the ore. Factor that in and solar power isn't all that environmental, especially not considering the need for a backup because of its intermitten nature.

Solar power is no more "free" than uranium is "free".

Well said solar is not free. Keep an eye though on http://www.futurepundit.com/archives/002789.html" . 60% efficient, no exotics, very cheap. In that case setting up a couple of 400 sq km arrays in, say, the vastness of the mojave or Texas somewhere, or even in the big ocean deserts might fly. Still need to find a way of keeping the cells clean at that scale.

 

[CaptainQuasar]

mheslep I don't know if it's the same thing you're talking about but a recent development - only commercialized in the last year or two - is thin-film solar cells. They basically use modern printing techniques to simply print solar cell circuits on an aluminum or other metal substrate, using no silicon at all, which drastically cuts the cost - by more than a third usually, I think, and even more importantly makes them considerably less fragile - they don't crack or shatter like silicon-based solar cells.

The prediction I've heard is that pretty soon every flat surface that gets sunlight - car roofs, semi trailer roofs, building walls and roofs - is soon going to be covered in solar panels, because why waste the sunlight when solar cells are cheap and physically flexible?

Check out this web brochure from a manufacturer:

http://www.powerfilmsolar.com/technology/index.htm

And this US DoE info page:

http://www1.eere.energy.gov/solar/thin_films.html

I believe all the manufacturers of this stuff are currently backordered for more than they can produce.

[EDIT]Oops, I just noticed that the brochure I linked to actually has the product using a polymer substrate and an amorphous silicon semiconductor. Oh, well - looks like the same lightweight manufacturing technology and flexible result I was talking about.

⚛​

 

[mheslep]

mheslep I don't know if it's the same thing you're talking about but a recent development - only commercialized in the last year or two - is thin-film solar cells. They basically use modern printing techniques to simply print solar cell circuits on an aluminum or other metal substrate, using no silicon at all, which drastically cuts the cost - by more than a third usually, I think, and even more importantly makes them considerably less fragile - they don't crack or shatter like silicon-based solar cells.

The prediction I've heard is that pretty soon every flat surface that gets sunlight - car roofs, semi trailer roofs, building walls and roofs - is soon going to be covered in solar panels, because why waste the sunlight when solar cells are cheap and physically flexible?

Check out this web brochure from a manufacturer:

http://www.powerfilmsolar.com/technology/index.htm

And this US DoE info page:

http://www1.eere.energy.gov/solar/thin_films.html

I believe all the manufacturers of this stuff are currently backordered for more than they can produce.

[EDIT]Oops, I just noticed that the brochure I linked to actually has the product using a polymer substrate and an amorphous silicon semiconductor. Oh, well - looks like the same lightweight manufacturing technology and flexible result I was talking about.

⚛​

DOE says they hope to thin films up to 10% efficient, or ~100W / M^2. - a bit tough to make a central power plant.

 

[CaptainQuasar]

DOE says they hope to thin films up to 10% efficient, or ~100W / M^2. - a bit tough to make a central power plant.

Would even 100% efficient really get you anywhere? I remember the CEO of Exxon-Mobil saying that it would take a surface of solar cells the area of New Jersey to equal the energy output of an average gas station. I didn't check those numbers - perhaps someone would like to work them out and see if this was total b▒▒▒▒▒▒t artistry - but it doesn't sound entirely off the mark to me. Even if you could equal a gas station's output with an acreage a tenth or a twentieth, or even a fiftieth of the area of New Jersey, dealing with time in the shade and everything, it seems like solar cells will never be more than a supplemental energy source.

⚛​

 

[mheslep]

I ran the numbers: Energy content of gasoline: 36.3 kilowatt-hrs / US gallon. Average gas station pumps 5000 gal / day = 181 megawatt-hours every day. Assuming good solar collection averages 10 hrs (?), the equivalent solar array has to have an average power 18 MW for 10 hrs. Solar irradiance is ~1KW/M^2 so at 100% efficiency you need 18,000 M^2 of arrays, or 0.14km on a side; at 60% 0.17km on a side; at 10 % about 0.5km or 0.25 km^2. How about for the gas needs of the whole state? Avg state has 2300 gas stations in the US = 575 km^2 of solar to produce enough electrical power for the equivalent of all the gasoline pumped every day. NJ btw is 22600 km^2, so 2% of NJ (1/50 as you say!) has to move over to convert from gas to 10% efficient solar. IF the solar array is 60% efficient then you need only 66km^2 or ~9x less area. Out in a state like Tx or Ok you'd probably never know the array was there, put it in some big rancher's field.

Probably need another 2x in here for weather and distribution losses.

 

[CaptainQuasar]

You live somewhere that's sunny for 10hrs every single day? I should move there. Before all the shady areas are covered with solar panels and all of the vegetation consequently dies. (Also, I think you might be a bit optimistic to be making calculations directly off of the total solar irradiance - working off of the actual production of solar arrays might produce lower numbers, I would suspect.)

But if you're right, and the power output of all the gas stations in a single state could be replaced with the solar output of one rancher's field (or nine rancher's fields at the current level of technology? Why are they bothering extracting and refining petroleum in Texas right now?) then I look forward to an extremely energy-rich future. Forget rancher's fields, you could easily float a solar array of any size off the coast anywhere in the U.S.

⚛​

 

[russ_watters]

But if you're right, and the power output of all the gas stations in a single state could be replaced with the solar output of one rancher's field (or nine rancher's fields at the current level of technology? Why are they bothering extracting and refining petroleum in Texas right now?) then I look forward to an extremely energy-rich future. Forget rancher's fields, you could easily float a solar array of any size off the coast anywhere in the U.S.

⚛​

Simple: solar panels are expensive. Being generous, if they cost you $2 per watt, that's $800 billion, just for the panels themselves. And for that, you haven't installed them, wired them, motorized them, converted their DC power to AC, kept them clean, or done an environmental impact study on the effect of blotting out the sun for such a large area.

 

[CaptainQuasar]

Simple: solar panels are expensive. Being generous, if they cost you $2 per watt, that's $800 billion, just for the panels themselves. And for that, you haven't installed them, wired them, motorized them, converted their DC power to AC, kept them clean, or done an environmental impact study on the effect of blotting out the sun for such a large area.

Numbers like that actually aren't so daunting - I mean, that's not http://www.cnn.com/2008/US/03/10/iraq.costs.ap/index.html" , right? Does that really compare unfavorably to petroleum prospecting, extraction, and refining infrastructure? (Or plus the transport infrastructure, if you count the fact that we already have a national and international transport grid for electricity generated from other sources.)

russ, do you think that solar could workably serve as a primary source of power as mheslep is suggesting? That seems like it would be pretty nice, actually, if it truly has that potential. But even as an omnipresent supplementary source of power, which I'm suspecting it might be relegated to practically, wouldn't be too bad.

⚛​

 

[vanesch]

As for hydrogen production, solar power is a "free" source of energy, wind and hydro are as well. What's more is the fact that we tend to make leaps in technological discoveries and this is one area where we can use a few. Remember that most computers used to need a warehouse to contain them and that your mobile phone used to be the size of an AK7. I have the feeling that there is an efficient and cheap method of hydrogen extraction just waiting to make someone a lot of money.

This is always the problem with the "ecologist's" opposition to nuclear power: they want to replace actual technology by dream technology. Of course dream technology is going to be better. Before you can propose on a large scale any industrial process, the fundamental research needs to be already done. You cannot base real-world strategies in the middle long term on the anticipation of fundamental research results that simply aren't there yet, and maybe never will be. It is what is happening in Germany: they are phasing out nuclear power, and wanted to replace it by wind power and other renewables.
IN PRACTICE, they are replacing it with coal power plants, simply because dream technology only works on paper and powerpoint presentations, but not with real power plugs.
So, in practice, they are making an ecological step backwards.

As to fuel cells, you don't need fuel cells to make electricity from hydrogen. If you already have the hydrogen, you can BURN it in gas turbines. THAT's an existing technology, which is moreover rather clean. So if you have the hydrogen, then the energy problem IS already solved. However, the only KNOWN way to produce hydrogen in industrial quantities is... by electrolysis of water ! (or by other chemical processes which are at least as energy-consuming, like having metals react with acids in water solution, which is in fact exactly the same reaction, but "in solution")

You see, the "solution" of the power problem with fuel cells is somewhat like proposing as a solution to buy a generator with a diesel engine. But you still need the diesel fuel!

Sorry to get off the topic, inadvertently. I am particularly interested in the safe mining and storage of nuclear material since I was one of many who helped to instill a 28 year long moratorium on uranium mining in my province.

Ah. And you also instilled a moratorium on coal mines ?

 

[vanesch]

Numbers like that actually aren't so daunting - I mean, that's not even one Iraq War, right?

For the price of one Iraq war, you'd have about 500 nuclear power plants by now, so you'd be all nuclear for the next 60 years or so.

 

[vanesch]

russ, do you think that solar could workably serve as a primary source of power as mheslep is suggesting? That seems like it would be pretty nice, actually, if it truly has that potential. But even as an omnipresent supplementary source of power, which I'm suspecting it might be relegated to practically, wouldn't be too bad.

⚛​

For the moment, solar power is still far too expensive to be competitive with nuclear generated electricity (which is the cheapest form of electricity production as of now, waste management included). However, wind energy is only about twice as expensive, and hence, it can be considered.

But these two sources have similar problems:
the size of the installations (and hence their ecological impact), and the intermittency of their production. Don't forget that there is a big factor between installed (maximum) power, and effective, average power. For wind energy in favorable places, this is a factor of about 6, and I think a similar factor for solar.

So even if one decided to go "all solar" and "all wind", you'd have to have a need for (fossile?) backup capacity that is of the same order as the full installation, with high flexibility ; in fact, only gas turbines can cope.

So this means that in the EFFECTIVE cost of such a solar/wind installation, you need to include the price of a SECOND complete power system, which moreover is based upon fossile fuel and which will probably be used for only a few tens of percents of its full capacity on average.

You don't see that in marginal cost calculations as long as you have minority contributions, because you are "stealing" flexibility from the majority system. Denmark is an example: about 20% wind energy, and almost totally relying on the flexibility of the German and Swedish power production, who compensate for the variability of the production. If they would be on their own, and they would go to 60% wind energy, then the cost of wind energy would drastically increase.