Fusion technology is the holy grail of energy generation: it promises clean sustainable energy, if only we could figure out those pesky "details." So pesky are those details that fusion power has seemingly been perpetually 20 years out. Always over the horizon, always progressing, but never coming to fruition. So it is not without a lot of trepidation that I'm going to suggest that General Fusion just might have solved the problem of nuclear fusion.
Fusion reactions are extremely hot. So hot in fact that they will melt any solid object we know how to make. The way scientists have conventionally worked around this issue is by something known as magnetic containment. Just like it sounds, this uses a magnetic field to keep the plasma far enough away from the container walls to keep them from melting. Unfortunately, generating this magnetic field is extremely energy intensive. Like generating the power for a small city intensive. Which means that bottling our little mini star has become the major roadblock to sustainable fusion – it takes more energy to produce the fusion reaction than the reaction itself produces. Lame.
Enter General Fusion. With a name that seems almost cloying, in the face of what has become one of mankind's most difficult challenges, like "Easy Cancer Cures", General Fusion has proposed a system that is, in many ways, not at all novel. Rather than containing the reaction with a magnetic field, which is energy intensive, or with some non-existent solids, they are proposing to contain it with liquid. Specifically, liquid that is only liquid at very high temperatures. The idea is to spin the liquid to make a little mini-funnel (think bathroom drain). The fusion reaction will heat the liquid, which will then be pumped out, and passed through a heat exchanger (think car radiator with molten metal instead of coolant and water instead of air) which will heat steam, which will then be passed through a conventional steam turbine. The beauty of the system is that cooling the system is also what allows the system to harness the energy.
There is one more component to this system, and it is also…well…elegant probably isn't the right word. It uses steam driven hammers operating in sync to send a shockwave through the spiraling liquid, compressing the plasma and igniting fusion. Like I said, not elegant, but certainly effective, and proven. In fact, this was very similar to the detonation method of the first atomic bombs: except they used dynamite instead of steam hammers.
All this sounds great, but what's the time table? A full-scale prototype built in 2015 and possible commercialization by 2020. FIVE YEARS.
Oh yeah, did I mention that it looks like something out of a steam punk nightmare?
If you want to see them talk about their own thing, there is a TED talk here