Fusion energy hurdle swept aside
news.bbc.co.uk
news.bbc.co.uk
Breakeven, though, is a lot tougher.
IMO, ITER's design should get to that point, but I don't think fusion is going to cost less than solar let alone coal for a long time.
PS: Using lasers to create fusion has always been more about simulating bombs than it was creating useful amounts of energy.
As for the simulation of bombs vs power, I think it depends on who you ask; scientists or DOE project managers?
It's interesting, after having left a PhD program in plasma physics (for fusion power,) I have a very different sense of the commercially plausible. All we're really using the fusion for is to create heat, and there are many ways to get heat inexpensively (solar, geothermal, coal, natural gas) that don't involve temperatures of hundreds of millions of degrees, that don't require superconducting coils, liquid helium cooling systems, ultra-high precision machined tungsten tiles, structural materials that are vaguely defined, completely unsourced, untested at the correct neutron fluxes, and rely upon rare earth elements, liquid lithium systems from which we're supposed to do tritium recovery (lithium is really reactive, tritium bubbles up and is explosive and diffuses through walls and embrittles them), liquid lithium walls on the inside of the chamber; high vacuum vacuum pumps, giant particle beams and incredibly non-linear and poorly understood science. You're comparing that to coal and mirrors and holes drilled in the ground and wind, all of which ultimately go into some kind of turbine (which is half or most of the expense!) The benefit of fusion just doesn't seem worth it for anything other than military applications or interstellar spacecraft. And really, we've got a lot to worry about before then...
From what I can tell the problem over the last 25 years with fusion is people keep saying what is the least amount of money we can spend and still make something useful. But, actually building a fusion reactor costs ~20 billion so we have been stuck prototypes when we need to shoot for the moon.
EDIT: Taking JET's design (http://en.wikipedia.org/wiki/Joint_European_Torus) and building a 10GW reactor would actually be easier than trying to build a 1GW reactor with the same basic design.
Also http://en.wikipedia.org/wiki/JT-60 "During deuterium (D–D fuel) plasma experiments in 1998 plasma conditions were achieved which would, if the D–D fuel were replaced with a 1:1 mix of deuterium and tritium (D–T fuel), have exceeded break-even"
It's possible that replacing D-D with D-T would have yielded break-even for a few seconds, (I've heard that claim before too) but I'm very skeptical; increasing the internal heat generation is sure to change the plasma conditions: for example, there would be a lot of adiabatic expansion, which, even restrained against the tokamak fields, is liable to have a variety of unstable modes.
Large Plasma devices are "the sexy" but IMO it's just another engineering problem at this point. And you don't design large scale power plants to sit at the outer edge of their capabilities 24x7. So yes, the highest energy pulses are unable after a few seconds, but we have built steady state fusion reactors they just operate further from their limits.
PS: Finding T is a problem, but "just build it bigger" and suddenly D-D (or 75%D - 25%T etc) becomes reasonable.
Edit: I am suggesting building building something with 4x ITER's budget which should give you ~8x the plasma volume and a lower surface area to volume ratio etc. We can also pump of the field strength etc. But you are limited to how much heat the wall can take so the plasma conditions don't need to be as efficient.
I do agree that the problem of controlling Q > 1 plasma becomes easier as you increase the volume. However, I don't think that's the biggest problem. As you yourself point out, you're limited in how much heat the wall can take. This is fundamentally the limiting factor in fusion power plant designs, unless a much more efficient direct conversion scheme is feasible. Why not instead take the tungsten panels you'd use and point a bunch of mirrors at it, achieving the same heat flux? Mirrors are just not that expensive.
PS: Do you work in fusion, by the way?
PPS: We should chat more. Send me a message at dfong at lightsailenergy.com
I was doing research on a kind of self-organizing plasma structure called an FRC. One of our big results was that we could stabilize the FRC to last for 100 milliseconds before it unwound itself. We have to pump a fair amount of energy in to make it in the first place!
As for the geothermal alternative, unfortunately it seems drilling holes to geothermal depths isn't easy or cheap either. Geodynamics in South Australia are arguably at the most advanced stage and they've had multiple drilling failures at their hot fractured rock geothermal pilot plant. They originally claimed that hot fractured rock geothermal drilling was in the regular 3-5km oil and gas depth "window" and thus should be straight forward. Ubiquitous geothermal from the mantle is much deeper still, so I suspect as a viable alternative to fusion you'd just be replacing one multi-billion dollar engineering challenge with another!
Engineered geothermal is at an extremely early stage, so I wouldn't count it out based on a few early failures.
- does not work by creating heat but by creating electricity directly (I am sure fusion creates plenty of high energy charged particles to make some electricity), and
- does not require any isotopes but fuses ordinary and plentiful atoms, such as ordinary hydrogen.
Well you are the scientist, get to it. After there are many alternatives but we all know their limitations. Regarding fusion, we know there is a potential for incredible amounts of energy that do not suffer most of the limitations of the other methods.
As to your second idea, it's already extremely hard to achieve break even with tritium, D-D fusion is even tougher and P-P fusion much much much tougher. We're now talking billion dollar projects, all to achieve an inexhaustible source of heat, which we effectively have in the form of the sun already!
Not everything is a matter of time. I'm not saying man's ingenuity won't figure it out, but the only place nuclear fusion takes place in nature is in stars, and that's powered by the pressure of a huge amount of mass, which can never be recreated on Earth. There has never been a goal-oriented technology project that has lasted this long, spent this much treasure, and produced so few results. Even brilliant people can engage in wishful thinking.
As for the wisdom of the NIF as public policy, that's something on which reasonable people can (and do) disagree. I'd only point out that the first government to master the goal of break-even fusion (getting more energy out of the reaction than is put in to trigger the reaction) will gain a _ridiculous_ economic advantage over the rest of the world, to say nothing of the non-economic benefits of energy independence. It's the kind of big bet that rich nations can (and in my opinion should) take.
It's pretty hard to keep big engineering secrets. As soon as the feasibility is proven, the fast followers will jump on the bandwagon.
The aggregate human quest for eternal youth and/or immortality?