In light of our troubled environment, one of the world’s most important pursuits involves the search for a source that can provide clean and unlimited energy. Basically, it’s a quest to find another sun, or at least a way to replicate our sun’s energy production process through a machine that can produce and control searing balls of plasma gas.
Right now, we have nuclear fission — the process of splitting atoms to generate energy. It’s successful in generating energy, but it fails in the ‘clean’ aspect as it produces much radioactive waste.
And then there is nuclear fusion. Instead of splitting atoms, the process involves bonding together of atoms, specifically, hydrogen atoms being subjected to high temperature and pressure until they combine to form helium atoms and release hot, charged plasma gas. Aside from using only seawater as fuel, this process can theoretically generate limitless energy, minus any harmful and toxic by-products.
Currently, there are two types of machines that have the potential to successfully bring about nuclear fusion — the tokamak and the stellarator.
A tokamak is a donut-shaped device that makes use of 2D magnetic fields (created by electric current passing through rings of magnets) to trap plasma long enough to allow nuclear fusion to take place.
On the other hand, a stellarator works by generating 3D magnetic fields, in twisted configurations instead of symmetrical rings, which makes it possible to contain the plasma without the need for any electrical current.
Compared with the tokamak which is dependent on electrical current and is therefore prone to disruption and incomplete fusion, the stellarator seems more stable because it only relies on the twisted magnetic fields it generates to hold the plasma in until fusion takes place. The challenge lies in making sure the magnetic fields are strong enough.
A few days ago, a team of US and German scientists working since last year on a stellarator — the Wendelstein 7-X (W 7-X) stellarator — has confirmed that their device is working as it should, producing magnetic fields that were as close as possible to their intended design.
According to their report published in Nature Communications, they were able to measure the error rate and it was impressively low at less than one in 100,000.
While the W 7-X stellarator isn’t designed to be the energy generator itself, proving that it is capable of producing the required magnetic fields is enough reason to move forward — use its concept and design to build the kind of reactor that we are envisioning, our own man-made sun.
And so the race to build the first fully functioning nuclear fusion machine has just become more interesting. On one end is ITER, France’s tokamak reactor. On the other end is the W 7-X stellarator, the result of collaborative work between Germany’s Max Planck Institute of Plasma Physics and the US Department of Energy. Both devices have shown the capability of containing plasma long enough to allow fusion to occur. We hope that soon enough, one or both will succeed in making nuclear fusion a reality.
An interesting note is the research done by Bussard and his work with inertial electrostatic confinement using a polywell design. It appears to be making progress as well.
The headline is incorrect: fusion energy, if it is made to work, will be anything but “free.” The capital cost of a fusion unit is always likely to be high, and operating cost (except for fuel, which is cheap, if not “free”) not negligible. Somewhere along the line, these real “costs” will need to be paid for. “TANOSTASE” – there ain’t no such thing as free energy.
Fusion offers potentially clean and abundant energy. Not free, and not unlimited.
The WX-7 Stellarator is very impressive. I hope it works. There are many people working now on fusion devices of various kinds. In 2006, I built a working IEC (Intertial Electrostatic Confinement) fusion device, which produced a very small neutron signature – just barely enough to detect. The technology is not difficult, and fusion-driven neutron generators have been the subject of patents since 1939. But as others have pointed out, the process is certainly not free. A lot of energy must be put *into* the process, before any net energy is generated. IEC devices are not uncommon, and have been developed by many private researchers, but the economics of the energy production is basically 1200 to 1500 watts of energy into the system, with 1200 to 1500 watts of heat and other energy output – with maybe (if you are careful & lucky), a couple of extra nano-watts from the deuterium-to-deuterium fusion activity. Scientifically interesting, but not of any economic use, unfortunately. You may even be able to generate a larger neutron flux by using a low-output radio-element (like the 241-Am (Americium) found inside a typical smoke detector).
What is interesting, is that D2-D2 fusion is possible, and you can build the device needed to make this happen, from parts sourced on internet. (I certainly did!) But the economics of the IEC technology are not promising. Very interesting, but not likely to provide any sort of useful net energy output. You can do much better with a wood-stove. Let the trees capture the fusion-energy from the sun, cut the trees down, cut and split up the wood, and burn it in a wood-stove with a good EPA energy efficiency rating. (I use a small Drolet stove to heat a decent-sized house. It works well.)
Capturing the abundant fusion energy generated by the sun is an actionable methodology, and also has reasonable economics. Not great, but at least net positive. You don’t have to convert it to electricity (but you can, if you want to.) In Japan, I saw roof-top solar-heaters used to heat the household water supply. These passive solar heaters were simple and very effective.
But I hope the WX-7 Stellarator can show a net energy output. That would be a very big, and very good result. For anyone interested, I’ve put a link to my company website, which has a note from 2006, with pictures, that I posted back then, describing the results of my IEC fusion experiments.