Sun-in-a-box: The shiny heat-resistant beryllium-coated interior of the JET (Joint European Torus) fusion reactor in Oxfordshire, England. Temperatures within the plasma can reach up to 100 million ºC - hotter than the core of the Sun.
Credit: JET/EFDA
Perfecting the fusion system will be a different matter, however. And it won’t be a speedy one. “ITER is an experimental demonstration device and will take about ten years to construct,” says Llewellyn-Smith. “Then we will have to run it for about ten years to get confidence in it, and to learn lessons from it, before we take the next step: the building of a real power station. That will take another ten years. So you end up at around 30 years from now as the earliest time you can expect to build a full-scale reactor that is producing electricity. And that is still not what you want – which is to see 50 of them out there contributing to the world’s energy. It will take even longer to get to that point. So, yes, it is going to be a very slow business.”
Nor should it be assumed that there will be no major problems encountered in scaling up from a reactor like JET to one that is the size of ITER – for there is a major qualitative difference between the two devices. With JET, which has been running since 1983, and its predecessors, plasma was heated by external sources, by engineers pumping in electrical power. On only a few occasions has fusion lasted long enough to generate significant amounts of power on its own. Things will be very different with ITER, however. More than 90 per cent of its heat will come from its own fusion reactions and it is conceivable that something new, unexpected and possibly unpleasant could happen. Some form of plasma instability could be triggered, for example.
It is a danger acknowledged by Holtkamp. “We simply don’t know how plasma will behave in these conditions. It could become unstable and the magnetic fields will not be able to contain it. Plasma could leak out and melt bits of the reactor,” he admits. Such an event would not threaten lives but it could cause serious, long-term damage that might set the cause of fusion power back many years. “For that reason we will be proceeding very cautiously when we get to the stage of burning plasma in the reactor,” adds Holtkamp.
In short, it is going to be a long, careful program. But, scientists like Llewellyn-Smith remain cautiously confident. “Yes, it is going to be very difficult, very challenging. I have no doubt about that. Nevertheless, I am confident we can make a fusion power station. The much harder question is this, however: can we make one of them reliable and economically competitive? At present our calculations suggest that fusion power will be competitive with current methods of power generation. However, it is very hard to be sure because we don’t know what we will be competing with as sources of power in the middle of the 21st century. However, I wouldn’t be here doing this job now if I didn’t believe fusion power was not going to play some role in energy generation in the future.”
Robin McKie has been reporting on fusion research for many years. He is the science editor of Britain’s The Observer, and a contributing editor of Cosmos.
And other approaches to fusion?
Fascinating article and it's nice to renew the feeling of optimism that has characterized the fusion program for so long. I do hope it works if for no other reason than to act as a step towards what will ultimately be the most widespread source of non-solar derived energy on the planet, doing for energy what the micro-processing and the silicon chip did for computational memory; making it, at long last, almost too cheap to meter.
I would have appreciated hearing a little bit about the burgeoning research in Inertial Electrodynamic Confinement (IEC) fusion which is being carried out now at many locations both academic and private research. The issues of containment of hot plasma seem to be bringing into focus the meaning of "hot" when describing velocities that approach the speed of light, which some thin IEC fusion may be effective at addressing whereas the large Tokomaks will not.
One researcher speculated that the reason the old USSR researchers gave the west the key elements of their research was not to further the research but to permanently hobble the west's research in fusion which up until that time had been through the work of Philo T. Farnsworth and Robert Hisch using high speed electron guns and magnets and a still rudimentary understanding of the problems they were encountering.
Even the rosiest estimates to break even still leave a lot of progress to be made before the Tokomak can ever be made even as portable as a modern day large scale electrical generator, and will initially require a huge outlay in infrastructure to apply its output. The IEC's approach forsees smaller and more ubiquitous, and non-radioactive, processes. Worth looking up the term Polywell Fusion for those interested.
Another alternative
Take a look at another alternative approach to fusion, which might prove cheaper, cleaner, more efficient, simple and easilly reachable.
At http://www.focusfusion.org
Same thing but cleaner !
So, what happens once you have fused all the Hydrogen on the planet to Helium ? Does not seem renewable in the long term. But maybe that will be the next generations problem .....
not really a concern
Since Hydrogen is by far the most abundant element in the universe, can be produced from water, and only small amounts are needed to fuse in order to release large amounts of energy; there no risk of running out of hydrogen within the lifetime of the planet.
Society
The problem with our society is that we spend trillions on wars, financial schemes, websites, lawyers, and other crap. There's no resources left to advance science. If we spent on science half of what we spent on sports or religion or politics, we'd solved sustainable nuclear fusion a long time ago.
Hell, we do everything we can to discourage people from entering sciences and engineering. From outsourcing jobs to arresting paleontologists for discovering a T-Rex skeleton.