# How many Fusion Power Plants to power humanity?

• Tiger Blood
In summary: The chain reaction starts and it keeps going and going and going. And it's like, BOOM, you get energy out.In fusion, the fuel is put into a doughnut-shaped device, and the doughnut is then put inside the magnetic field. ... energy is released when the parts of the doughnut that are closer to the magnets start to heat up.
Tiger Blood
I watched that documentary by Dr. Brian Cox about nuclear fusion development and in one segment Dr. Saul Griffith tries to calculate how much would World need renewable power sources like wind farms, solar panels, hydroelectric generators etc. to substitute oil use completely in like 20 years and he came up with impossible numbers, so that in the end he said "Nuclear fusion would be a jail free card for humanity."

So I was wandering how much nuclear fusion power plants would you need to substitute current electrical consumption in the world? Would it be enough something like five fusion power plants for the whole Europe?
But then I presume you would expect to use the power to make methanol to substitute oil use for cars and other vehicles.

A fusion power plant would probably have similar output to a fission or coal power plant. So you would need several hundred to replace all the current power plants.

With plentiful electricity generated by fusion (or fission for that matter) you can use electrolysis to split water into hydrogen for clean burning fuel for vehicles. To replace all transportation fuel with hydrogen generated by electrolysis (or just for electric cars with batteries) you would need roughly double the number of power plants as we have now as transportation energy is around the same as grid energy usage.

berkeman
Well it doesn't seem to me that fusion is even comparable to fission, because in the documentary they conclude that combined humanity today uses around 30 terawatts of energy (all energy from electricity to cars and planes), so they make an experiment to see what it would take to substitute all that energy with clean resources in 25 years period.
They divide the 30 terawatts number and assign that just 5 terawatts gets produced in next 25 yrs by fission and they get that it would take 5000 nuclear power-plants or 2,5 new fission power plants every week. Or every 3 minutes new full sized wind turbine.

So my guess is that fusion generator would produce much more energy, because I don't think they or anybody else sees fusion power plants working in tandem with fission or solar or wind even.

Those numbers don't sound right to me. Nuclear today amounts to about 10% of all electric production over ~400 reactors. So 5000 reactors should be enough to supply all electric demand, and another 5000 could be enough to supply transportation demand (only in the raw numbers sense though, in reality it wouldn't be that simple). Over 25 years that comes out to 400 reactors per year. No small feat, but within the realm of feasibility if it really came down to that.

There is nothing special about fusion power that would suggest that it would have a greater power density compared to fission or fossil power plants. Both fission and fusion power plants could probably be scaled up indefinitely, but why would you want to? That would put all your eggs in one basket.

Stephanus
Since fusion power has been 20 years away for at least 50 years I wouldn't depend on it for the near future.

Ryan_m_b, dragoneyes001 and CalcNerd
The medium and long term potential of D-D fusion to power the world at a level of 60 TW giving everyone living on the planet fair access to energy -

The complete conversion of deuterium nuclear fuel releases an energy content of 250 x 10^15 joules per metric ton of deuterium. The quantity of deuterium in the world’s oceans is estimated at 4.6 x 10^13 metric tons. Deuterium present in seawater will yield around 5 x 10^11 TW-year of energy. In the year 2014 the entire planet consumed around 17 TW-years of energy, which means that the energy content of the deuterium in seawater would be enough for 29.4 billion years of energy supply.

To give all 10 billion people expected to live on the planet in 2050 the level of energy prosperity we in the developed world are used to, a continuous average use of power of 6 kilowatts per person as is typical in Europe, we would need to build 60,000 one gigawatt fusion power plants to generate 60 terawatts as a planet—the equivalent of 900 million barrels of oil per day.

The time since the Earth first formed = 4.54 billion years. The time until the sun burns out = 5 billion years. The deuterium in the sea is capable of completely powering planet Earth at a level of 60 Terawatts for 8.33 billion years (longer than the Earth has existed or the sun will burn)

Stephanus
QuantumPion said:
There is nothing special about fusion power that would suggest that it would have a greater power density compared to fission or fossil power plants.

Scientifically power density might be similar, but there is one huge difference between the two technologies.

In fission, all the fuel is together inside the reactor thingie. If there's a problem, the fuel requires management to allow a cold shut down. The default state of an operational reactor is to continue with fission until positive controlled external action is taken. It's fail deadly. There are psychological /political reasons why you might not want a super dooper huge mega reactor next to the city where your mother lives. Consider German's nuclear strategy vis-a-vis Fukushima.

In fusion, the majority of the fuel is outside the reactor. In an emergency you can just shut the fuel off. In extremis, you can cut the fuel line with a hot spanner and fusion will cease with only minimal damage /possible limited melt down. Similarly the highly sophisticated ignition /containment system can be easily disrupted. The tendency of an operational fusion reactor is to stop unless positive controlled external action continues. It's fail safe(ish). It's hugely safer.

If fusion is perceived as being safer, Mother might be happy to have larger fusion reactors than fission reactors. So you might have less of them.

(Just be careful where you site the exhaust port.)

OK I get it. I did a little research and the answer is that there should also be lots of fusion power-plants made but they will be cheap and electricity will be cheap considering that today you don't just pay for electricity bill and pump bill but also devastation of environment, medical bills because they pollute your body and of course war for oil that is costing trillions of dollars. All fusion needs is some sea water which is free and always will be free.

And then the next generation of nuclear fusion reactors will be even more stable and productive. Some day the inhabitants of this planet will look back at the clumsy magnetic bottle, the D–T tokamak, which will seem like an old IBM Selectric typewriter with font balls compared to Microsoft Word on a 3-GHz notebook computer. The deuterium–tritium reaction is a terrible fusion reaction, but we have to start with it because it is easy to ignite. I mean look how far we made from Wright Brothers to Space Shuttle in just one century or from the first computers till ipads.

I would also recommend an excellent book "An Indispensable Truth: How Fusion Power Can Save the Planet" by Francis Chen

Because from what he writes it also depend on us when we will have fusion power-plants. We should press the politicians to devote more money and urgency to it. Even Dr. Brian Cox said that there should be Manhattan-like project but to develop fusion.

Here is what Francis Chen says:

The path is clear, but the rate of progress is limited by financial resources. In the USA, fusion has been ignored by both the public and Congress, mainly because of the lack of information about this highly technical subject. People just do not understand what fusion is and how important it is. Books have been written light-heartedly dismissing fusion as pure fantasy. The fact is that progress on fusion reactors has been steady and spectacular. The 50-year time scale presently planned for the development of fusion power can be shortened by a concerted international effort at a level justified by the magnitude of the problem. It is time to stop spinning our wheels with temporary solutions.

and

A high-priority Apollo-like program to put fusion on a fast track will cost less than Apollo did and will solve the CO2 problem, the fossil-fuel shortage problem, and the oil dependence problem all at once.

MathewsMD and Stephanus
mathman said:
Since fusion power has been 20 years away for at least 50 years I wouldn't depend on it for the near future.
Yeah, and 20 years later fusion power is still 20 years away.
But I hope ITER has some good news

Fusion power is always fascinating me

robertsteinhaus said:
The complete conversion of deuterium nuclear fuel releases an energy content of 250 x 10^15 joules per metric ton of deuterium. The quantity of deuterium in the world’s oceans is estimated at 4.6 x 10^13 metric tons. Deuterium present in seawater will yield around 5 x 10^11 TW-year of energy
5 x 10^11 TW x (sec x min x day) joules for how many Q in power plant? 10?
robertsteinhaus said:
...which means that the energy content of the deuterium in seawater would be enough for 29.4 billion years of energy supply
In what year level of world energy needs? 2010?

Stephanus said:
Yeah, and 20 years later fusion power is still 20 years away.
But I hope ITER has some good news

It would be more accurate to say that fusion power has always been 20 billion dollars away. But the funding has been stagnant or decreasing until recently when ITER finally got started.

bhobba and Stephanus
QuantumPion said:
It would be more accurate to say that fusion power has always been 20 billion dollars away. But the funding has been stagnant or decreasing until recently when ITER finally got started.
But 20 billions dollars is not that "much".
If I remember correctly in Gulf War II, 1991. US spent 1 billion dollar per day.

robertsteinhaus said:
The medium and long term potential of D-D fusion to power the world at a level of 60 TW giving everyone living on the planet fair access to energy -

The complete conversion of deuterium nuclear fuel releases an energy content of 250 x 10^15 joules per metric ton of deuterium. The quantity of deuterium in the world’s oceans is estimated at 4.6 x 10^13 metric tons. Deuterium present in seawater will yield around 5 x 10^11 TW-year of energy. In the year 2014 the entire planet consumed around 17 TW-years of energy, which means that the energy content of the deuterium in seawater would be enough for 29.4 billion years of energy supply.

To give all 10 billion people expected to live on the planet in 2050 the level of energy prosperity we in the developed world are used to, a continuous average use of power of 6 kilowatts per person as is typical in Europe, we would need to build 60,000 one gigawatt fusion power plants to generate 60 terawatts as a planet—the equivalent of 900 million barrels of oil per day.

The time since the Earth first formed = 4.54 billion years. The time until the sun burns out = 5 billion years. The deuterium in the sea is capable of completely powering planet Earth at a level of 60 Terawatts for 8.33 billion years (longer than the Earth has existed or the sun will burn)
A very, very bright future!
But the main question remains. When will we be able to build the box?

Tiger Blood said:
A high-priority Apollo-like program to put fusion on a fast track will cost less than Apollo did and will solve the CO2 problem, the fossil-fuel shortage problem, and the oil dependence problem all at once.

This perception annoys me, and is a fallacy.

The Zeitgeist suggests fusion = zero oil dependency = zero CO2. What am I typing this on? A plastic computer made from oil. I bought it by driving a car lubricated by oil, along an asphalt road made from oil. The trendy t-shirt I'm wearing is made from polyester with it's ancestry in a distillation column. And I cooked my dinner on a LPG powered cooker.

Energy /transport only accounts for roughly 2/3rds of oil consumption. We'll by pumping out oil and CO2 for a good while yet, no matter how many fusion reactors we have

dragoneyes001, DEvens, russ_watters and 1 other person
mathman said:
Since fusion power has been 20 years away for at least 50 years I wouldn't depend on it for the near future.
So...roughly the same number of fusion plants as invisible purple unicorns on hamster wheels?

Seriously, how can we speculate about the capacity of a power source that doesn't exist?

QuantumPion said:
It would be more accurate to say that fusion power has always been 20 billion dollars away.
Disagree. Cost estimating inventions is even less reliable than scheduling them.

nikkkom, dragoneyes001 and DEvens
Tiger Blood said:
. All fusion needs is some sea water which is free and always will be free.
And a processing facility and power plant, which are definitely not free...

...and the 50+++ years of development costs.
And then the next generation of nuclear fusion reactors
Hopefully, we will be able to call the next generation the first generation of actual generators...

...will be even more stable and productive.
...and "produce" an output greater than 0.
The path is clear, but the rate of progress is limited by financial resources...

The 50-year time scale presently planned for the development of fusion power can be shortened by a concerted international effort at a level justified by the magnitude of the problem. It is time to stop spinning our wheels with temporary solutions...

A high-priority Apollo-like program to put fusion on a fast track will cost less than Apollo did and will solve the CO2 problem, the fossil-fuel shortage problem, and the oil dependence problem all at once.
So it's cheap, when compared to the most expensive project in the history of the world? ...though already 5x longer, without success?

Doesn't sound like a great deal to me. If we had chosen to, like France, we could have been 100% nuclear, 30 years ago and this issue should be moot.

I've given up on fusion and come to the conclusion: why bother? It really offers nothing relevant that fission couldn't have already given us.

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nikkkom
russ_watters said:
So it's cheap, when compared to the most expensive project in the history of the world? ...though already 5x longer, without success?
Why do you think it's the most expensive? Keeping up Moore's law is far more expensive, every time you pull out your mobile phone it's trillions of dollars of research that went into it and yet it's in the palm of your hand.

russ_watters said:
Doesn't sound like a great deal to me. If we had chosen to, like France, we could have been 100% nuclear, 30 years ago and this issue should be moot.

I've given up on fusion and come to the conclusion: why bother? It really offers nothing relevant that fission couldn't have already given us.

It is a good question: if we had fusion what makes it so different that it won't go the way of the fission?
Possible reasons why there is not more fission power plants:
1. people don't like them around. They are afraid
2. it takes lots of time to build them: something like 6 years just to get the permits and then 4 years to build them
3. you have to mine uranium and uranium mines are an ugly and expensive places
4. radioactive waste. We all know that only one plant produces 30 tons of radioactive waste a year, if we had much more of them around then imagine all those trains and trucks driving around with nuclear waste: what if there is a train accident? What if they become target for terrorists?
5. stigma of connecting it with nuclear weapons. Having fission power plant means you can easily make a big bomb
6. they are a hazard and therefore not recommended to by built in "less developed" nations

Differences and similarities that fusion will and will not confront:
1. People would welcome them, they would not be afraid of them
2. Probably very complicated to be built but likely not more then fission.
3. No mining what so ever
4. Waste in minute quantities and degradable in just few years
5. no stigma of using it to make nuclear weapons
6. They are not a hazard and they absolutely do not pose a danger to anyone around and could be built near towns, so even more electricity could be saved

Stephanus
Paul Uszak said:
Energy /transport only accounts for roughly 2/3rds of oil consumption. We'll by pumping out oil and CO2 for a good while yet, no matter how many fusion reactors we have
But we can build machines that purifies CO2 from atmosphere, and these machines are powered buy fusion power

Tiger Blood said:
Differences and similarities that fusion will and will not confront:
6. They are not a hazard and they absolutely do not pose a danger to anyone around and could be built near towns...,
Yep, they could be built in the middle of town, or in an island three miles away

Tiger Blood said:
Why do you think it's the most expensive? Keeping up Moore's law is far more expensive, every time you pull out your mobile phone it's trillions of dollars of research that went into it and yet it's in the palm of your hand.
The cell phone has existed as a commercial product for decades. We didn't spend hundreds of billions of dollars to invent the first cell phone. It bears no resemblance to the so far wasted costs of developing fusion power.
It is a good question: if we had fusion what makes it so different that it won't go the way of the fission?
Possible reasons why there is not more fission power plants:
1. people don't like them around. They are afraid
While true, it isn't a very good reason.
2. it takes lots of time to build them: something like 6 years just to get the permits and then 4 years to build them
Longer than that, but fusion plants are unlikely to take less time, particularly if they are larger.
3. you have to mine uranium and uranium mines are an ugly and expensive places
Sure -- as will be deuterium processing.
4. radioactive waste. We all know that only one plant produces 30 tons of radioactive waste a year, if we had much more of them around then imagine all those trains and trucks driving around with nuclear waste: what if there is a train accident? What if they become target for terrorists?
We've successfully stored radioactive waste for decades. It really isn't an actual problem, just a political one.
5. stigma of connecting it with nuclear weapons. Having fission power plant means you can easily make a big bomb
The stigma part is true, the connection with nuclear weapons never was very valid. Besides: we already have nuclear weapons, so building more nuclear plants won't change that.
6. they are a hazard and therefore not recommended to by built in "less developed" nations
We're a long way from fusion power even being built in developed nations and developed nations use far more power than "less developed" ones - and there is no telling if "less developed" nations could even make it work. So I don't think this is a very relevant concern. It doesn't address why the US hasn't already gone full nuclear.
Differences and similarities that fusion will and will not confront:
1. People would welcome them, they would not be afraid of them
Ironic, but probably true.
2. Probably very complicated to be built but likely not more then fission.
3. No mining what so ever
4. Waste in minute quantities and degradable in just few years
5. no stigma of using it to make nuclear weapons
All probably true, but not significant advantages. (And while you don't "mine" water, you do have to process it to get deuterium, which will not be zero-cost.)
6. They are not a hazard and they absolutely do not pose a danger to anyone around and could be built near towns, so even more electricity could be saved
It is tough to know what the hazards will be with a fusion plant, but we can be sure they will not be zero. In any case, I live about 5 miles from a nuclear plant already. I'm glad it is there instead of a coal plant: much safer/healthier.

Anyway, none of these reasons seem very compelling to me. None represent dealbreakers for fission or significant improvements for fusion. Remember: France is already 100% fission and has been for decades. There really aren't any good reasons why the US couldn't have already done it as well.

How about this: while we wait another 50 years for fusion, we can build and run fission plants through their 50 year life-cycle and when they are ready to be shut off, maybe fusion will be ready to replace them. Sound good? Fission is here now and it works. We should implement it instead of hoping fusion will happen soon. We've already wasted many decades and shouldn't waste any more.

Ryan_m_b, DEvens and Stephanus
russ_watters said:
All probably true, but not significant advantages. (And while you don't "mine" water, you do have to process it to get deuterium, which will not be zero-cost.)
Yes, that's true. If I'm not mistaken about 1 in 6500 part of hydrogen in sea water is deuterium. But if somehow we can build a very efficient enrichment deuterium factory, mostly automaton, powered by electricity (which comes from fusion for example) The cost still would not be zero, but it is very low I think.
russ_watters said:
It is tough to know what the hazards will be with a fusion plant, but we can be sure they will not be zero. In any case, I live about 5 miles from a nuclear plant already. I'm glad it is there instead of a coal plant: much safer/healthier.
Really? You live 5 miles from one? Surely the pollution issue for nuclear power plant even if it is fission is much smaller compared to coal plant.
But somewhere I read, the difference between fission and fusion power plant in fuel supply is this:
In fission, all the fuel are inserted in the reactor. While in fission, only a small gram of plasma is injected in the reactor.
The process to prevent chain reaction in fission reactor is by inserting a rod, I forget what it is, to absorb neutrons.
And if it fail, all the fuel will be reacted at once, in nano second compared to normal power plant process which years.
Is it not dangerous?
How fail safe is it?

russ_watters said:
How about this: while we wait another 50 years for fusion, we can build and run fission plants through their 50 year life-cycle and when they are ready to be shut off, maybe fusion will be ready to replace them. Sound good? Fission is here now and it works. We should implement it instead of hoping fusion will happen soon. We've already wasted many decades and shouldn't waste any more.
Another difference between fission and fusion power plant is, as you likely already know, fission fuel is not distributed everywhere. We have to FIND some uranium mining. While sea water is everywere. Or just water, not necesseraly sea water, right?

Stephanus said:
Really? You live 5 miles from one?
So I just checked on Google Earth: 5.9 miles, actually. I'm in the suburbs of Philadelphia, PA, USA. The plant is 30 miles from the center of Philadelphia, but more than a million people live in the PA suburbs of Philadelphia (and another million in Philadelphia).
Surely the pollution issue for nuclear power plant even if it is fission is much smaller compared to coal plant.
Yes, infinitely smaller: zero.
But somewhere I read, the difference between fission and fusion power plant in fuel supply is this:
In fission, all the fuel are inserted in the reactor. While in fission, only a small gram of plasma is injected in the reactor.
The process to prevent chain reaction in fission reactor is by inserting a rod, I forget what it is, to absorb neutrons.
And if it fail, all the fuel will be reacted at once, in nano second compared to normal power plant process which years.
Is it not dangerous?
How fail safe is it?
Well, what you describe - all of the fuel reacting at once - isn't really possible in a nuclear plant. The fuel is not anywhere close to dense enough to explode like a nuclear bomb. It is inherrently impossible.
Another difference between fission and fusion power plant is, as you likely already know, fission fuel is not distributed everywhere. We have to FIND some uranium mining.
While that's true, so what? There is plenty of uranium available to power the next several generations of humanity - perhaps the next several hundred generations - on fission. Fuel availability really doesn't present a meaningful near-term obstacle. Heck, the fuel is cheap and plentiful right now that we just throw it away when we are done with it instead of recycling it!

DEvens and Stephanus
russ_watters said:
Pollution?Yes, infinitely smaller: zero.
Except for the radioactive waste. CO2 pollution is of course, zero!

russ_watters said:
There is plenty of uranium available to power the next several generations of humanity - perhaps the next several hundred generations - on fission.
Several hundred generations! Really?
I should have googled it, but since we are in chat mode ...
Can you give me the figure, if it's not too much trouble for you, how many joules does 1 Kg U235 liberate? Or perhaps 1 kg of uranium isotop, a mixed of U235 and U238?
How many tonnes are the world Uranium production per year?

russ_watters said:
Fuel availability really doesn't present a meaningful near-term obstacle. Heck, the fuel is cheap and plentiful right now that we just throw it away when we are done with it instead of recycling it!
Come on... The universe is 75% hydrogen. And 1/6500 of it is Deuterium, as if in the far future human can't fuse P+P...

Stephanus said:
Pollution, by definition, is the introduction of a harmful substance into the environment. A properly functioning nuclear plant does not release its waste into the environment and therefore really is zero pollution.
Can you give me the figure, if it's not too much trouble for you, how many joules does 1 Kg U235 liberate? Or perhaps 1 kg of uranium isotop, a mixed of U235 and U238?
How many tonnes are the world Uranium production per year?
I don't know any of that off the top of my head, so your google is as good as mine. Here's some data:
It [uranium] is about 500 times more abundant than gold and about as common as tin.

U3O8 is the uranium product which is sold. About 200 tonnes is required to keep a large (1000 MWe) nuclear power reactor generating electricity for one year...

Some 27 tonnes of fresh enriched fuel is required each year by a 1000 MWe reactor.

Typically, some 44 million kilowatt-hours of electricity are produced from one tonne of natural uranium. The production of this amount of electrical power from fossil fuels would require the burning of over 20,000 tonnes of black coal or 8.5 million cubic metres of gas.
http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Introduction/Nuclear-Fuel-Cycle-Overview/
Come on... The universe is 75% hydrogen. And 1/6500 of it is Deuterium...
The abundance of hydrogen does not make uranium scarce.

DEvens and Stephanus
russ_watters said:
Pollution, by definition, is the introduction of a harmful substance into the environment. A properly functioning nuclear plant does not release its waste into the environment and therefore really is zero pollution.

I don't know any of that off the top of my head, so your google is as good as mine. Here's some data:

http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Introduction/Nuclear-Fuel-Cycle-Overview/

The abundance of hydrogen does not make uranium scarce.
Thanks

russ_watters said:
Typically, some 44 million kilowatt-hours of electricity are produced from one tonne of natural uranium. The production of this amount of electrical power from fossil fuels would require the burning of over 20,000 tonnes of black coal or 8.5 million cubic metres of gas.
Okay, okay, fission is better, much better than oil. It's just I hope we'll have a cheap fusion in the near future.
As I recall in one of Stephen Hawking video in youtube.
What future development that he wants to see before he dies.
Perhaps he said 5. One of them was the operational of fusion power. But as I remember exactly, not one about Lou Gherig disease!
Of course I can't give you the source video. It's been along times since I watch it.

russ_watters said:
The cell phone has existed as a commercial product for decades. We didn't spend hundreds of billions of dollars to invent the first cell phone. It bears no resemblance to the so far wasted costs of developing fusion power.
Yeah right for those that carry their cellphones in the big backpack, but for those with small phones that have fast processors that can connect them to the internet where they can watch videos come directly from investment in Moore's law.

russ_watters said:
Sure -- as will be deuterium processing.
In what universe is sucking ocean water and digging huge dusty holes the same?

russ_watters said:
It is tough to know what the hazards will be with a fusion plant, but we can be sure they will not be zero. In any case, I live about 5 miles from a nuclear plant already. I'm glad it is there instead of a coal plant: much safer/healthier.
Well what does that has to do with anything? The fact that you're glad you live near nukes does not mean that majority of people is. Most people consider fission plants to be leaky and blame their cancers for it. Like this:

For instance it doesn't mean that if you would like to fly in Concord that that plane will be back in business again.

russ_watters said:
Again in what universe is France is already 100% fission and has been for decades? Just looking at wikipedia it says "Looking purely at electricity, though, 407 TWh (75%) out of the country's total production of 541 TWh of electricity was from nuclear power, the highest percentage in the world."
But I also watched recently a documentary about France's nuclear past and they constantly battled protests while building them and they said to be completely energy independent they would have to build something like 70 more plants.

russ_watters said:
How about this: while we wait another 50 years for fusion, we can build and run fission plants through their 50 year life-cycle and when they are ready to be shut off, maybe fusion will be ready to replace them. Sound good? Fission is here now and it works. We should implement it instead of hoping fusion will happen soon. We've already wasted many decades and shouldn't waste any more.

Well yeah that's the theme here. In 2020 it is expected for ITER to test sustainability of a fusion reaction – a continuous “burn.” operated for ten years or more. Another large machine will be needed simultaneously to solve engineering problems not included in the ITER project. After that, the first power-producing fusion reactor, DEMO, is planned... Now all that could be sped up, which is a question.
But unfortunately it won't come that fast because unlike expensive development of fission and keeping up the Moore's law army doesn't need it so it's left on people. Imagine if someone asked people decades ago if they wanted to invest trillions of dollars over couple of decades just to be able to phone and send pictures to people from where ever point they are they would answer NO! They would say: "Are you nuts? You can always use phone-booth, can't you wait to call your mommy? What about just decades ago when people didn't have any phones and had to use mail? So grow up!" and yet today we can not imagine our lives without mobile phones and internet. It's because we changed and we're changed now, we can not go backward and unfortunately can't stay the same but go forward.
So wanting fission and wind is like wanting more phone booths, and more video stores and more magazines with letters columns instead of mobile phones and internet.

BTW there are some scientists who really see fusion as unlocking the new age of humanity, I mean I don't know how much this is practical but this is what Dr. Robert Zubrin writes: "If we can get fusion, we will be able to use the superhot plasma that fusion reactors create as a torch to flash any kind of rock, scrap, or waste into its constituent elements, which could then be separated and turned into useful materials. Such technology would eliminate any possibility of resource exhaustion of this planet. Using fusion power, we will be able create space propulsion systems with exhaust velocities up to five thousand times greater than the best possible chemical rocket engines. With such technology, the stars would be within our reach."

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You seem a fan of fusion.
Me, too. But what russ_watters say makes sense. Fission is ok, while we wait for fusion to be available.
And it is much more "ok" than coal or oil. But in the future I think fusion is the answer. It's not a joke!
Because there is joke roaming that fusion is the energy of the future, and in the future, fusion is STILL the energy of the future. But I put my faith in fusion. Hope there will be available at least 100 years from now.

Tiger Blood said:
Well what does that has to do with anything? The fact that you're glad you live near nukes does not mean that majority of people is. Most people consider fission plants to be leaky and blame their cancers for it. Like this:
I hope she will be cured. My mother has cancer, too. My prayer...

Tiger Blood said:
Using fusion power, we will be able create space propulsion systems with exhaust velocities up to five thousand times greater than the best possible chemical rocket engines. With such technology, the stars would be within our reach.

But, my dear Tiger Blood, interstellar travel is much more complicated than just fusion.
Assuming you want to propel a rocket to the nearest star. Alpha Centauri the weight of the rocket is 1000 tonnes.
How much energy would you need?
Before that, I'll give you the list of energy liberated in some reaction per kg of fuel
http://www.mpoweruk.com/nuclear_theory.htm#fusionfuels
https://en.wikipedia.org/wiki/Energy_density

All in joules
U235: 8.1 x 1013
D-T: 3.27 x 1014, assuming the reactor if 100% efficient. Q>100 or something.
Chemical: 4.6 x 106
Anti matter: 9 x 1016, twice if you only carry antimatter, the other half, you can react it with wood you bring along in the rocket or you mines scattered hydrogen atom in the journey.
Anti matter: 18 x 1016, Half antimatter, half matter
If you propel the rocket, say in 1 g, about 10N along the way,
Half of the journey you turn around the rocket and fire it again to have a slow down effect. In all, you accelerate along the way.
So, here is the parameter:
Weight: 1,000,000 kg
Force: 10kg m/s2
Distance: 40 trillions KM = 40,000 trillions metres
The energy needed is
##F = M.a##
##E = F.d##
##E = M.a.d##
##E = 10^{6} x 10 x 4 x 10 ^ {16}##
##E = 4 x 10^{23} \text { joules}##
Travel time: 6 years?? That's General Relativty things which I completely don't understand, sorry
That way, you'll reach relativistic speed. And it would take much more energy than that.

Here I give you how much fuel should the rocket bring to gain that much energy.
All in tonnes
U235: 5,000,000
D-T: 1,020,000
Chemical: 87 trillions
Antimatter: 4000
Half anti matter: 2000

So, it's very difficult I think for just putting a tokamak inside the rocket.
The weight of a tokamak it self is for example, 23,000 tonnes. 23 times the weight of the rocket. The D-T fuel? Well, 1.2 millions tonnes!
https://www.iter.org/factsfigures

Can it be done, if we mine whatever protons or deuteriums that we find along the way??
After all the interstellar density is 106 per cm3
https://en.wikipedia.org/wiki/Interstellar_medium

Tiger Blood said:
"If we can get fusion, we will be able to use the superhot plasma that fusion reactors create as a torch to flash any kind of rock, scrap, or waste into its constituent elements, which could then be separated and turned into useful materials. Such technology would eliminate any possibility of resource exhaustion of this planet. Using fusion power, we will be able create space propulsion systems with exhaust velocities up to five thousand times greater than the best possible chemical rocket engines. With such technology, the stars would be within our reach."
Zubrin's statement is an over-simplification and belies a misperception of science and technology.

Firstly, there are limited resources on the planet, and much of the planet is not readily accessible.

Secondly, high specific impulse generally means low thrust, and one still needs to haul the propellant. Even with fusion technology, we will not find 'stars within our reach'.The challenges with fusion systems are considerable, and they will generate radwaste through activation of structural elements, particularly if the fuel is d,t. There is considerable research into radiation resistant/tolerant materials, but a fast neutron flux will necessarily challenge any structural material.

Extraction of deuterium from seawater is expensive.

nikkkom and DEvens
Well yeah Zubrin seems to be going over his head although I did read some of his books and he really goes into the details of how fusion rockets could work. Nevertheless fusion does seem to be something special because for instance when scientists mention Kardashev scale of types of civilizations it's usually mentioned that when humans get nuclear fusion we will become type 1 civilization.

When it comes to fission I think it's thing of the past. Beside it being clunky there is too much bad rep about it. Just remember what happened after Fukushima disaster: In the aftermath, Germany accelerated plans to close its nuclear power reactors and decided to phase the rest out by 2022. Italy held a national referendum, in which 94 percent voted against the government's plan to build new nuclear power plants. In France President Hollande announced the intention of the government to reduce nuclear usage by one third. China suspended its nuclear development program briefly, but restarted it shortly afterwards.

Tiger Blood said:
Well yeah Zubrin seems to be going over his head although I did read some of his books and he really goes into the details of how fusion rockets could work. Nevertheless fusion does seem to be something special because for instance when scientists mention Kardashev scale of types of civilizations it's usually mentioned that when humans get nuclear fusion we will become type 1 civilization.

When it comes to fission I think it's thing of the past. Beside it being clunky there is too much bad rep about it. Just remember what happened after Fukushima disaster: In the aftermath, Germany accelerated plans to close its nuclear power reactors and decided to phase the rest out by 2022. Italy held a national referendum, in which 94 percent voted against the government's plan to build new nuclear power plants. In France President Hollande announced the intention of the government to reduce nuclear usage by one third. China suspended its nuclear development program briefly, but restarted it shortly afterwards.
There's 1 thing bothering me about Chernobyl. Why Hiroshima and Nagasaki (God Rest Their Soul) are habitable, while Chernobyl is inhabitable, at least for thousands (if not ten of thousands) of year. But it should be to other thread.
The level of civilization is not just fusion. Michio Kaku says (and this one I remember the name) that it's not just energy but how we live also. The Internet if the characteristic if type 1 civilization among other thing.
And to reach that level, the civilization must consume/produce some amount of power. Forgot how much terawatt.

Stephanus said:
There's 1 thing bothering me about Chernobyl. Why Hiroshima and Nagasaki (God Rest Their Soul) are habitable, while Chernobyl is inhabitable, at least for thousands (if not ten of thousands) of year. But it should be to other thread.

Chernobyl is not uninhabitable by any means, many people still work there and plant and animal life is not significantly affected. The high level radioactive Cs and Sr will be gone in 100-200 years. To answer your question though, a fission power reactor contains vastly more fuel and fission products than a bomb. A bomb contains 50 kg of U while a reactor contains 50 tons. A reactor produces as much energy as a fission bomb every ~6 hours and runs continuously for years.

Stephanus
Paul Uszak said:
What am I typing this on? A plastic computer made from oil.
More precisely that plastic is made up of polymers of carbon and hydrogen. Fossil hydrocarbons are currently necessary for the energy they contain, but are not required their elements, though they are currently the most economic source.

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