Tokamak runs for 29 hours

[G7PSK]

A tokamak has been run in Oxford for 29 hours so is fusion going to be here within the 30 years. I hope so as fusion is the only real hope to meet our future energy needs.

http://www.tokamakenergy.co.uk/about-us/

[LabSpokane]

I'm reading that as they ran high-temperature superconducting magnets for 29 hours.  I don't think they're claiming to fuse atoms for 29 hours, or are they? 

[Mechanical Menace]

Not to belittle the achievement but given the lack of fanfare I'm guessing it wasn't self sustaining?

EDIT: Actually having finally noticed the tweet I'll second LabSpokane's question and also ask how progress on harnessing the energy is coming on?

[con-f-use]

The current position is that even ITER is too small to sustain fusion at break-even. Even if we had a working break-even now, it would take at least 40 years to design, build and implement fusion reactors, that are commercially viable. The technology is very complicated an expensive. As a physicist I don't expect to see it in my lifetime. Sorry to crush your hopes.

[Artlav]

The technology is very complicated an expensive. As a physicist I don't expect to see it in my lifetime. Sorry to crush your hopes.

And then comes the plasma wakefield accelerator, and a 7.5 billion euro, country-spanning LHC gets shrunk to a car-priced tabletop device.

I suspect it's just a matter of finding a way how to make a reactor, rather than trying to build that hugely complex and expensive thing.

[free_electron]

We already have a working fusion reactor. It pumps out 3.83×10^26 watts, and delivers wireless energy to large parts of the planet 24/7. Zero running costs too, zero waste.

zero maintenance and a 1 million year warranty ...

The problem is that 'the powers that be' don't like the idea of everyone using this fre eenergy. they want to bill you for it.

[rolycat]

We already have a working fusion reactor. It pumps out 3.83×10^26 watts, and delivers wireless energy to large parts of the planet 24/7. Zero running costs too, zero waste.

Only(!) 174 petawatts actually arrives on Earth, though.
So you could say it 'wastes' 2.2 billion times as much energy as it delivers.
If you were feeling energetically geocentric.

[con-f-use]

Fusion will be more costly than solar for quiet some time in the future. If anything a fusion-reactor is useful during night time as a supplement to renewable energies.

[tom66]

I wonder if fusion will be easily throttleable, or if it will be like nuclear, and will generate energy continuously? If it's the latter, then it could create problems for grid stability that will require extra storage to be built out.

[con-f-use]

Here is a nice interactive outreach primer (~250MB) on fusion in general and its commercial application. It was made by the "European Consortium for the Development of Fusion Energy" and is scientifically sound. Even they state, it won't be until 2050 that we have commercial fusion. Since they are mostly scientists and politicians, I'd say they are overly optimistic, but not by much. One of the biggest problems is funding. ITER was build as a ~6m fusion camber. The initial recommendations from the science side of things were 8m minimum. That would have made for a nice break-even and sensible science to be done. Politicians essentially said, they're only going to fund the smaller version. So they ended up building another one (DEMO) and setting the science back a few years. All just because someone was a cheap bastard. 

[coppice]

I wonder if fusion will be easily throttleable, or if it will be like nuclear, and will generate energy continuously? If it's the latter, then it could create problems for grid stability that will require extra storage to be built out.

All the techniques tried so far for fusion are very controllable. Fuel is fed into the reactor as it is needed. Stop the flow of fuel, and you stop the reactor with very little lag.

[tggzzz]

A tokamak has been run in Oxford for 29 hours so is fusion going to be here within the 30 years. I hope so as fusion is the only real hope to meet our future energy needs.

And in 400 years the oceans boil. Simple thermodynamics of a black-body radiator such as the earth, coupled with current rate of increase of energy usage. If you magically assume that all energy use becomes 100% efficient, then the oceans will boil in 440 years.

See http://physics.ucsd.edu/do-the-math/2011/07/can-economic-growth-last/ for full discussion; the above is very abbreviated!

[con-f-use]

Well yes, its mostly throtteable with a few minor quirks. You have effects like the H-modes that need certain conditions to reach a high efficiency, but you could switch between those and actually but net energy into your plasma in the mean time. It's nothing you're keen on doing, but it would work.

[con-f-use]

And in 400 years the oceans boil. Simple thermodynamics of a black-body radiator such as the earth, coupled with current rate of increase of energy usage. If you magically assume that all energy use becomes 100% efficient, then the oceans will boil in 440 years.

Assuming we haven't found a way to cool or leave earth by than. Radiating energy into space or putting up large reflectors over especially hot spots or the like. People usually find a way to prolong their suffering, if it really need be. I know he cautions against believing technology cures everything, but I strongly belief humans can solve their problems, if really really hard pressed to the brink of extinction. At great costs of course.

[John Coloccia]

What we need are fusion roadways.

[Artlav]

What we need are fusion roadways.

Well, there were the Radium roadways in the 40s...

[LordNobady]

What we need are fusion roadways.

Sounds like a kickstarter. how much GW* do you think you can get per square meter. When will you start, I like to see Dave debunk it. 


* I mean if a solar pannel can claim KW fusion must make GW don't you think. 

[tggzzz]

And in 400 years the oceans boil. Simple thermodynamics of a black-body radiator such as the earth, coupled with current rate of increase of energy usage. If you magically assume that all energy use becomes 100% efficient, then the oceans will boil in 440 years.

Assuming we haven't found a way to cool or leave earth by than. Radiating energy into space or putting up large reflectors over especially hot spots or the like. People usually find a way to prolong their suffering, if it really need be. I know he cautions against believing technology cures everything, but I strongly belief humans can solve their problems, if really really hard pressed to the brink of extinction. At great costs of course.

Please do the arithmetic and physics; his points are pretty fundamental.

What is your suggested way for cooling the earth? Have you considered, for example, that a reflector will keep heat in as well as a little sunlight out?

The historical evidence that "humans can solve their problems...extinction" is they don't and do go extinct. You don't even have to cross the water to see it: go south into Mexico and the Andes! It is very unwise to bet on a change in human nature.

[con-f-use]

Good point, but let me ask you: If you really think we are irredeemably doomed for extinction, why aren't you more of a dick? I'm assuming, you don't rape, steal and constantly live off of other people (even in situations, where you think, you'd never be caught). I'm asking because that or catatonia would be the ultimate response to such a dire expectation.

Of course putting reflectors up is a silly plan (but they do keep much more heat out, than they hold in). You missed my point there. I wasn't seriously suggesting that exact means to solve the issue. Neither was I doubting the numbers or advocating a "the problem will solve itself" attitude. I'm merely remarking that people become very ingenious, when they have to. I just had the pleasure of listening to a member of the Manhattan Project lecture about it. Even they didn't belief they could do it. Yes, we'll have to put effort into it, and yes countless people will suffer, but I really don't think, we'll go extinct. And one final point: Other civilisations went extinct because of war or some dispersed into a more powerful one. You are talking about humans actively intending for the others to vanish, not about us being inactive and impassive as a whole species. It is in human nature that the latter will likely not happen.

[Mechanical Menace]

We need to build a Dyson sphere to stop all this waste!

Wouldn't work. A Dyson swarm might.

[con-f-use]

And the thread needs to go back on track... Fusion is nice, but won't cure everything and certainly not overnight.

[LabSpokane]

I wonder if fusion will be easily throttleable, or if it will be like nuclear, and will generate energy continuously? If it's the latter, then it could create problems for grid stability that will require extra storage to be built out.

Where are you getting this information?  France has been load following with their reactors for years. Running reactors as base load only is a combination of design and regulatory issues.

How far one is able to turn down the reactor (or any thermal plant) is driven substantially by the plant's ability to provide proper steam quality. If the steam becomes wet, it will erode the turbine blades. A coal or wood-fired boiler would have similar constraints.

[tggzzz]

Other civilisations went extinct because of war or some dispersed into a more powerful one. You are talking about humans actively intending for the others to vanish, not about us being inactive and impassive as a whole species. It is in human nature that the latter will likely not happen.

That's true in some cases, but false in others. The classic clear-cut example is the Easter Islanders, who had a flourishing civilisation until they cut down all their trees - and couldn't even make boats to escape.

There are many other examples in all continents (except Antartica!) where the cause of their demise was over-use of their local environment weakened them significantly - which allowed other people to overrun them.

Unlimited fusion power would cause as many problems as it solves.

[tggzzz]

I wonder if fusion will be easily throttleable, or if it will be like nuclear, and will generate energy continuously? If it's the latter, then it could create problems for grid stability that will require extra storage to be built out.

Where are you getting this information?  France has been load following with their reactors for years. Running reactors as base load only is a combination of design and regulatory issues.

How far one is able to turn down the reactor (or any thermal plant) is driven substantially by the plant's ability to provide proper steam quality. If the steam becomes wet, it will erode the turbine blades. A coal or wood-fired boiler would have similar constraints.

True, but an over-simplification. Many plants "dislike" simple thermal cycling. There is the concept of "dispatch", which is more immediately applicable to renewables, and is discussed in this good paper: http://www.templar.co.uk/downloads/Renewable%20Energy%20Limitations.pdf

[edavid]

[And in 400 years the oceans boil. Simple thermodynamics of a black-body radiator such as the earth, coupled with current rate of increase of energy usage. If you magically assume that all energy use becomes 100% efficient, then the oceans will boil in 440 years.

See http://physics.ucsd.edu/do-the-math/2011/07/can-economic-growth-last/ for full discussion; the above is very abbreviated!

It's a very silly paper.  Why would energy usage continue to increase at the current rate?  What would people do with that much energy?