cpihl

Totally correct. Right now we simply purchase D2 gas in small quantity so the price is relatively high. But even at those prices we'll probably spend on the order of only $100 per month on D2 when we're operating.

It is. We use electromagnets to make the plasmas, move them, and finally compress them all without moving parts, just magnetic field.

We'd certainly be concerned about those kinds of applications. Fortunately we don't use beams in this approach. The plasma used in the Fusion Engine is akin to a balloon or pillow, granted - a really hot pillow, but luckily a terrible projectile.

I love this question because it helps illustrate just how different fusion is from other energy sources. If it works, a 50 MW Fusion Engine would run for 5-10 years on a single 55 gallon drum of heavy water.

Close but with some important differences. We've tried that approach and it has some interesting potential applications but, when it comes to building a power plant that has to last decades, we think the engineering is just too difficult. Instead of pushing on a liner that then pushes on the plasma, we directly push on the plasma with magnetic field. The engineering, while still difficult, is much easier to tackle.

That's a good question. The short answer is the energy that it takes to extract D2 from water is so small compared to the fusion energy released it isn't a factor. That is reflected in the cost of D2O at about $0.70 per gram. In a fusion reactor, even with inefficiencies, that gram of D2O will create about $1000 worth of electricity.