Our energy future depends on nuclear fusion, says Michel Laberge. The plasma physicist runs a small company with a big idea for a new type of nuclear reactor that could produce clean, cheap energy. His secret recipe? High speeds, scorching temperatures and crushing pressure. In this hopeful talk, he explains how nuclear fusion might be just around the corner.
Some quotes from Michael Laberge
Fusion is often criticized for being a little too expensive. Yes, it did cost a billion dollars or two billion dollars a year to make this progress. But you have to compare that to the cost of making Moore’s Law. That cost way more than that. The result of Moore’s Law is this cell phone here in my pocket. This cell phone, and the Internet behind it, cost about one trillion dollars, just so I can take a selfie and put it on Facebook. Then when my dad sees that, he’ll be very proud. We also spend about 650 billion dollars a year in subsidies for oil and gas and renewable energy. Now, we spend one half of a percent of that on fusion. So me, personally, I don’t think it’s too expensive. I think it’s actually been shortchanged, considering it can solve all our energy problems cleanly for the next couple of billions of years.
Now magnetic and laser fusion are pretty good machines. They are awesome pieces of technology, wonderful machines, and they have shown that fusion can be done. However, as a power plant, I don’t think they’re very good. They’re way too big, way too complicated, way too expensive, and also, they don’t deal very much with the fusion energy. When you make fusion, the energy comes out as neutrons, fast neutrons comes out of the plasma. Those neutrons hit the wall of the machine. It damages it. And also, you have to catch the heat from those neutrons and run some steam to spin a turbine somewhere, and on those machines, it was all a bit of an afterthought. So I decided that surely there is a better way of doing that.
One way [to generate energy from nuclear fusion] in particular attracted my attention, and it’s called magnetized target fusion, or MTF for short. Now, in MTF, what you want to do is you take a big vat and you fill that with liquid metal, and you spin the liquid metal to open a vortex in the center, a bit like your sink. When you pull the plug on a sink, it makes a vortex. And then you have some pistons driven by pressure that goes on the outside, and this compresses the liquid metal around the plasma, and it compresses it, it gets hotter, like a laser, and then it makes fusion. So it’s a bit of a mix between a magnetized fusion and the laser fusion. So those have a couple of very good advantages. The liquid metal absorbs all the neutrons and no neutrons hit the wall, and therefore there’s no damage to the machine. The liquid metal gets hot, so you can pump that in a heat exchanger, make some steam, spin a turbine. So that’s a very convenient way of doing this part of the process. And finally, all the energy to make the fusion happen comes from steam-powered pistons, which is way cheaper than lasers or superconducting coils.
Now, this was all very good except for the problem that it didn’t quite work. (Laughter) There’s always a catch. So when you compress that, the plasma cools down faster than the compression speed, so you’re trying to compress it, but the plasma cooled down and cooled down and cooled down and then it did absolutely nothing.
So when I saw that, I said, well, this is such a shame, because it’s a very, very good idea. So hopefully I can improve on that. So I thought about it for a minute, and I said, okay, how can we make that work better? So then I thought about impact. What about if we use a big hammer and we swing it and we hit the nail like this, in the place of putting the hammer on the nail and pushing and try to put it in? That won’t work. So what the idea is is to use the idea of an impact. So we accelerate the pistons with steam, that takes a little bit of time, but then, bang! you hit the piston, and, baff!, all the energy is done instantly, down instantly to the liquid, and that compresses the plasma much faster. So I decided, okay, this is good, let’s make that.
So we built this machine in this garage here. We made a small machine that we managed to squeeze a little bit of neutrons out of that, and those are my marketing neutrons, and with those marketing neutrons, then I raised about 50 million dollars, and I hired 65 people. That’s my team here. And this is what we want to build. So it’s going to be a big machine, about three meters in diameter, liquid lead spinning around, big vortex in the center, put the plasma on the top and on the bottom, piston hits on the side, bang!, it compresses it, and it will make some energy, and the neutron will come out in the liquid metal, going to go in a steam engine and make the turbine, and some of the steam will go back to fire the piston. We’re going to run that about one time per second, and it will produce 100 megawatts of electricity.
Okay, we also built this injector, so this injector makes the plasma to start with. It makes the plasma at about a lukewarm temperature of three million degrees C. Unfortunately, it doesn’t last quite long enough, so we need to extend the life of the plasma a little bit, but last month it got a lot better, so I think we have the plasma compressing now. Then we built a small sphere, about this big, 14 pistons around it, and this will compress the liquid. However, plasma is difficult to compress. When you compress it, it tends to go a little bit crooked like that, so you need the timing of the piston to be very good, and for that we use several control systems, which was not possible in 1970, but we now can do that with nice, new electronics.
So finally, most people think that fusion is in the future and will never happen, but as a matter of fact, fusion is getting very close. We are almost there. The big labs have shown that fusion is doable, and now there are small companies that are thinking about that, and they say, it’s not that it cannot be done, but it’s how to make it cost-effectively. General Fusion is one of those small companies, and hopefully, very soon, somebody, someone, will crack that nut, and perhaps it will be General Fusion.