The future of electricity

In literally 1 week, the entire future of the human race may have changed. And this time, the chances of that happening are reasonably high.

In Germany on the 10th of December, the future of humanity may have been changed by one lab in northern Germany. We may have access to near-infinite, cheap, renewable power. We are that close.

At the Max Planck Institute of Plasma Physics, an experimental fusion generator called the Wendelstein 7-X has been completed. It is due for its first experimental test on the 10th of this month. Being plasma physics, the chances are that it won’t work first time. But if it does…

Fusion power has been the Holy Grail for applied physicists for the past few decades. Ever since the 1920s when the idea was first proposed, there has been a steady effort to try to crack controlled fusion. And I use the word ‘controlled’ for very good reason. We have, as a species, started uncontrolled nuclear fusion reactions. They look like this.

The energy unleashed when multiple atoms are fused, rather than split (as in a standard nuclear fission reactor), a tremendous amount of energy is released – several orders of magnitude more that in fission. If we could tap into that power, we could generate an almost unbelievable amount of power from almost nothing. Unlike fission, the basic fuel of a fusion reaction is hydrogen, rather than heavy elements like uranium or plutonium or thorium. These heavy elements are rare in the universe, and take a lot of energy to find and extract. Hydrogen is the most abundant element in the entire universe. The effort of getting some hydrogen is the effort of the electrolysis of water, or whatever other technique is used to extract it. Peanuts compared to uranium.

But nuclear fusion is tricky. The tremendous amount of energy released is enough to turn the hydrogen into superheated plasma, which is hot enough to melt through virtually every substance known to man. But that energy is containable. The real problem is overheating the reactor itself.

When you are dealing with clouds of million-degree hydrogen, whatever you use to hold it will heat up very, very fast. The current experimental reactors can withstand these levels of heat for, at most, just under 10 minutes. And even though the rate of energy production is so tremendous, 10 minutes of energy production is not a lot when compared to the ignition energy.

When you want to start a fusion reaction, you have to pour a massive amount of energy into some hydrogen. At the moment, research labs use superpowered lasers to heat hydrogen to these kinds of temperatures. The energy needed to do this is way, way above the kind of energy you can produce from a reactor in 10 minutes. So as it is, fusion reactors take more energy to start than can be extracted.

Now, there are multiple ways to contain a fusion reaction. Almost all of these involve utilising a magnetic field to hold the plasma in a vacuum. But there are differences in the shape and configuration, which leads to dozens of variations.

The most commonly used type of experimental reactor is a tokamak.

This uses a doughnut-shaped (donut) reactor with a powerful magnetic field to contain the plasma. This is currently being researched most heavily, as it is simpler than other designs. The problem is, it overheats very fast from the plasma being forced into a particular shape. It has a maximum operational span of about 9 minutes. And 9 minutes is not enough to get back 100 million degrees worth of laser power.

But there is another design that can be used – a stellarator.

It is much, much more complicated than a tokamak because, rather than forcing the plasma into a doughnut shape, the reactor itself is modelled on the shape the plasma naturally. This involves a lot of extremely hard maths which I’m not even going to pretend to understand, but the end result looks like this.

The Wendelstein 7-X stellarator has been under construction in Germany for the past decade or so, and has been finished in the past few months. And in 7 days, the first experimental tests will be run. And in theory, the 7-X reactor can run for much longer than a tokamak.

In theory, it can run for 30 minutes.

That might not sound like the Holy Grail of physics, but a 30 minute run time for a fusion reactor is like a 1 hour marathon. Sure, it might not be long enough to get a net gain in power. But technology improves over time. And I would much rather bet on a 30-minute stellarator becoming the key to commercial fusion power than a 9-minute tokamak.

But even after that, the stellarator isn’t going to be the perfect Holy Grail. It took 10 years to build and design the 7-X reactor, commercial rollout isn’t going to be quick. The true goal, the key to unlimited power, is cold fusion.

Cold fusion is a fusion reactor that works close to room temperture. And by room temperature, I mean below a million degrees. If we could find a way to start a fusion reaction at that temperature, we could quite conceivably end up with an infinite power supply.

So, the Wendlestein 7-X reactor isn’t the future of humanity in a bottle. But if the first test run is successful, and we can find a way to make a net power gain from that thing…

Welcome to the future.


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