The end of nuclear energy

[Realitycheck]

There was an article today on physorg.com detailing a long list of limitations spelling out a limited future to nuclear energy, if you didn't already know that. The exercising of great care won't be much of a factor when you consider the sheer volume of energy used worldwide compared to the limited amounts of reactor fuel (unless you plan on filtering out the few ppm of it from the entire ocean.)

 

375 GW Total energy produced by nuclear reactors

15 TW Total energy consumption worldwide

15,000 Total number of nuclear reactors required to meet worldwide demand

 

Plus, the long list of dangers, hurdles and setbacks really just contributes to an effort in futility when compared to a green future.

Edited May 12, 2011 by Realitycheck

[lemur]

What about hydrogen fusion? I know that still requires some radioactive material, but isn't the power-output significantly greater per unit power produced? Also, can't a fusion reactor sustain its reactions without adding radioactive fuel? I.e. can't the hydrogen keep the hydrogen fusing on its own?

 

edit: But what would you do when all the water was gone after millions of years of fusing hydrogen into helium? Would Earth end up like Mars?

Edited May 12, 2011 by lemur

[Realitycheck]

Well, when they figure out a way to effectively contain the astronomical temperatures involved on an industrial scale, then I will change my mind.

[Danijel Gorupec]

Breeder reactors are not that fuel limited (http://en.wikipedia.org/wiki/Breeder_reactor or http://charming.awardspace.com/plutonium/plutonium.html). As far as I know, there are no comercial breeder reactors today (experimental only).

 

Fusion reactors are not limited in fuel, but are future technology. Posibly not that far future (http://en.wikipedia.org/wiki/ITER). Note that first version of fusion reactors will use fuel that is somewhat limited, but some advanced future version might use pure hydrogen. And we have plenty of hydrogen.

 

I don't think that you can produce 15TW from any source and call it green. Collecting and concentrating that much energy will certainly have much impact on environment. Todays green energy sources are only green because are marginally used. Therefore, I think, only real green technologies are ones that reduce our energy needs (either from reducing intrinsic consumption or from increasing efficiency).

 

 

 

 

[CaptainPanic]

Danijel, I agree with almost all you say in your post, but why wouldn't solar or wind energy be green (if applied at a 15 TW scale)? Especially wind energy is just using nature's waste heat.

 

If we would look at a theoretical case where we would supply all the 15 TW by wind energy (no matter how impractical that would be for certain applications), then we'd need 6 million 2.5 MW wind turbines, which are just very ordinary wind turbines.

 

6 million sounds like a lot, but if you realize that the earth's land surface is 150 million km2, then we would have only 1 wind turbine in every 25 km2 (1 wind turbine in every 5x5 kilometer block). And if we'd build some at sea, or if we would use larger wind turbines (more power), that area would be even larger.

 

Honestly, I don't think that that's such a big impact on the environment.

[Danijel Gorupec]

Well, I suppose that it depends how we define 'green'. I think that 15TW must produce some footprint on the environment (wind towers visible all over the landscape, solar cells covering the land, road network to many power plants...)

 

I agree that this footprint is going to be tolerable and manageable. But I don't think that it will be any smaller than if we decided to use nuclear energy instead. I personally hope that we will develop both technologies and use them wisely.

 

(btw, I don't think that a 2.5MW wind turbine is 'ordinary one' - sure, it will probably become ordinary in near future. Also, we will have to install more than 15TW (maybe 50TW) to cope with unreliable energy source - the wind. Third, not all land is equally suitable for wind turbines or solar cells and you will have to have some concentration that will increase footprint locally.)

 

 

 

[CaptainPanic]

btw, I don't think that a 2.5MW wind turbine is 'ordinary one' - sure, it will probably become ordinary in near future. Also, we will have to install more than 15TW (maybe 50TW) to cope with unreliable energy source - the wind. Third, not all land is equally suitable for wind turbines or solar cells and you will have to have some concentration that will increase footprint locally.

Again, I agree with your post, and I just wish to comment on one point (which is dangerously off-topic, so I wouldn't mind if mods split this off).

 

This link shows (and I quote) 'the ‘top ten’ wind turbine manufacturers, as measured by global market share in 2007, and some salient features of the technology of some of their flagship designs'.

 

The flagship designs have power ratings of 3, 2.5, 2, 2, 2.1, 3.6, 3, 0.75, 2.5, 1.5 MW. The averave value of that is in fact 2.3 MW (so, quite close to the 2.5 I said).

 

I think it's important to realize the current status of wind energy... that such big turbines are nowadays common.

In fact, Vestas is going to have a 7 MW windturbine prototype next year, and they're planning commercial construction of those in 2015! And that's no dream, or plan. That's entered the stage of actually building it.

 

To get this a little bit back on topic... you only would need 143 of these huge wind turbines to replace a complete nuclear power plant.

Edited May 12, 2011 by CaptainPanic

[swansont]

What about hydrogen fusion?

 

Net amount of energy produced by terrestrial hydrogen fusion, with the exception of bombs, is negative.

[Danijel Gorupec]

The flagship designs have power ratings of 3, 2.5, 2, 2, 2.1, 3.6, 3, 0.75, 2.5, 1.5 MW. The averave value of that is in fact 2.3 MW (so, quite close to the 2.5 I said).

 

You are right on this one... I had no idea that output power grew that large. Amazing.

 

Of course, nuclear power plant is also scalable.... The difference between wind and nuclear is that with wind we will have to live 'inside' the power plant (towers will be all around us). While with nuclear, we will isolate the plant outside our everyday living space. Both solutions are possible, I beleive.

[pwagen]

Net amount of energy produced by terrestrial hydrogen fusion, with the exception of bombs, is negative.

 

Does that mean all hope is lost in regards to fusion power plants?

[CaptainPanic]

Does that mean all hope is lost in regards to fusion power plants?

It means we cannot base any policy on it. We cannot make any plans for it.

 

We cannot say: "By 2030 we want to have 5% of our energy from fusion"... because it is not a matter of political will or funding. We just can't seem to get it to work properly.

[swansont]

It means we cannot base any policy on it. We cannot make any plans for it.

 

We cannot say: "By 2030 we want to have 5% of our energy from fusion"... because it is not a matter of political will or funding. We just can't seem to get it to work properly.

 

Exactly. It's not even a matter of taking something that works in the lab and transitioning it into a commercial product.

[pwagen]

Ah, so by "terrestial hydrogen fusion", you mean the technology we so far have come up with? Not the theoretical upper limit, so to speak?

[lemur]

It means we cannot base any policy on it. We cannot make any plans for it.

 

We cannot say: "By 2030 we want to have 5% of our energy from fusion"... because it is not a matter of political will or funding. We just can't seem to get it to work properly.

It's really not such a bad thing considering that every little bit of hope for abundant future energy causes people to relentlessly waste present sources. Still, is there really any fundamental physical reason why hydrogen fusion cannot be accomplished in a reactor?

 

 

 

[Moontanman]

I think it's necessary to bring up thorium reactors as well, uranium is not the only fissionable element in the earth's crust and there is lots of thorium. Breeder type reactors give us leeway to use lots more than U-235.

[Realitycheck]

It's really not such a bad thing considering that every little bit of hope for abundant future energy causes people to relentlessly waste present sources. Still, is there really any fundamental physical reason why hydrogen fusion cannot be accomplished in a reactor?

 

Because having to produce tocamaks to perform fusion on a miniature scale already makes the process inefficient, even if we could scale it up. Maybe we could devise a way to produce cold fusion that produces no energy, though I doubt it. Or maybe we could meet somewhere in between. Still lots of science to do.

 

http://www.physorg.com/news/2011-05-nuclear-power-world-energy.html

Edited May 13, 2011 by Realitycheck

[swansont]

Ah, so by "terrestial hydrogen fusion", you mean the technology we so far have come up with? Not the theoretical upper limit, so to speak?

 

Stellar fusion obviously works, and we have ways of exploiting solar energy in various ways. But no reactors here on earth have sustained a break-even reaction for very long, and that has to happen before you can think of harnessing the output.

[CaptainPanic]

Ah, so by "terrestial hydrogen fusion", you mean the technology we so far have come up with? Not the theoretical upper limit, so to speak?

 

Still, is there really any fundamental physical reason why hydrogen fusion cannot be accomplished in a reactor?

 

All problems regarding fusion are practical, not theoretical / fundamental.

 

Hydrogen bombs and the stars and sun show that fusion works. But the practical problems are absolutely enormous...

[Danijel Gorupec]

Absolutely enormous, yes... But solvable. I feel that decision to go for it would not be entirely unreasonable, even at this moment. What is needed is another "We choose to go to the Moon" type of speech (possibly on Chinese?). I feel that technology leap would not be any greater than it was for the appolo project.

 

 

[lemur]

Absolutely enormous, yes... But solvable. I feel that decision to go for it would not be entirely unreasonable, even at this moment. What is needed is another "We choose to go to the Moon" type of speech (possibly on Chinese?). I feel that technology leap would not be any greater than it was for the appolo project.

But going to the moon was a frontier. Abundant nuclear energy is about turning the thermostat down. That's not quite as inspirational, imo.

[CaptainPanic]

Absolutely enormous, yes... But solvable. I feel that decision to go for it would not be entirely unreasonable, even at this moment. What is needed is another "We choose to go to the Moon" type of speech (possibly on Chinese?). I feel that technology leap would not be any greater than it was for the appolo project.

I'm not convinved it's necessary... and I'm not convinced that simply throwing (like in the Apollo-program) more money at it will make fusion an economically interesting energy source within a decade.

 

Also, the goal is just to get a secure source of clean energy that strengthens the economies worldwide... it does not necessarily have to be fusion power.

Why wouldn't the existing (and working) technologies such as wind and solar be able to do the job? They're clean. They can be built everywhere, enabling a secure supply. And they start to become profitable too... in other words: they tick all the boxes. If you're gonna invest money like we're going to the moon again, why not use those technologies?

 

Don't forget that ITER alone already got 15 billion (billion with a B). It's not like they do not get any money. It may not be the Apollo project, but it's still pretty damn big.

[Hal.]

http://www.centrica.com

http://www.centrica.com/index.asp?pageid=923

Edited May 13, 2011 by hal_2011

[Danijel Gorupec]

Why wouldn't the existing (and working) technologies such as wind and solar be able to do the job?

 

Hmm... I cannot give you math equations. It is simply that I feel (guess) that you are overly optimistic regarding 'wind and solar' energy sources. I think that we will need something in addition (nuclear fusion is a candidate).

 

What I know is that harvesting non-concetrated energy is always more expensive than harvesting energy from more concentrated source. Therefore, I expect that wind and solar energy will always be more expensive than nuclear energy (mass production may decrease this difference, but I don't think it can annulate it). Here on west (I am actually in eastern Europe) expensive energy might seem like reasonable price to pay, but what about Africa?

 

Of course, I don't think that fusion can be comercially ready within a decade. 25 years, maybe. However, the possibility that once we will posses as cheap and as powerful energy source as the nuclear fusion is appealing.... I see that humanity is aggresive and energy-hungry. And if we limit ourselves to wind and solar only, we will have to recede a little.

 

At the moment, I think we can only choose from wind, solar, biomass, geothermal and/or nuclear. And only the last one seems plenty enough to sustain our current 'way of life'. (Note that I don't promote it and I would actually like more modest society.) I am talking about 10-20 fold energy consumption increase in next 100 years.

 

(I also think that nuclear fusion will prove much greater benefit to humanity than the Appolo program, therefore we can spend 10 times as much. Only if we decide that this is the way we want/need to go.)

 

 

 

[CaptainPanic]

What I know is that harvesting non-concetrated energy is always more expensive than harvesting energy from more concentrated source.

That's a general engineering rule of thumb, and as a thermodynamic argument, I would agree. But you say it's "expensive", and that means you include practical considerations as well.

 

And if you include practical issues, they I think that there is an optimum. If energy gets too concentrated, harvesting it becomes a problem again.

 

But I admit that this is also just a feeling.

 

But actually, you have a very excellent point. If we assume that (1) the world population will continue to grow as it does, and (2) the energy consumption increases per person as well, then indeed, we'll be looking at a 10-20 fold increase of energy consumption (and more). And we can argue that sooner or later, fusion and fission are the only possible sources of energy, because the sun simply doesn't deliver enough anymore.

 

If we agree that this is a realistic scenario, then we must invest heavily in fusion a.s.a.p.

 

However, in today's world, the motivation to get sustainable energy is different. There is no lack of sunlight or wind.

[lemur]

But actually, you have a very excellent point. If we assume that (1) the world population will continue to grow as it does, and (2) the energy consumption increases per person as well, then indeed, we'll be looking at a 10-20 fold increase of energy consumption (and more). And we can argue that sooner or later, fusion and fission are the only possible sources of energy, because the sun simply doesn't deliver enough anymore.

The problem that no one seems to want to face is that it's not just about population growth. It's about current elite standards of living that set the bar high for expectations about the level everyone globally wants to raise their standards of living to. Currently there are mad levels of political resistance in the developed economies to migration from economically poorer regions. But what is it in 'the west' (or the north, east, or south, depending on where you are and where you want to go) that appeals to poorer people globally? Having a car and the freedom (fuel) to drive it around a lot and go practically anywhere you want? Having a well-built insulated house with year-round climate control? Access to fashionable clothes and venues to display them (and yourself) in fresh exciting ways on a regular basis? Shopping? As a friend of mine who like to rap told me, it's about "the cars, the clothes, the money, and the hoes." This lifestyle is energy intensive, so how can any source create enough energy to make it possible for everyone globally to live this way? If not, doesn't it become a question of how to start making low-energy living more comfortable in order to deconstruct energy-intense western culture?