New fusion reactor design from MIT

[nwdiver]

Solar isn't a magic wand. It has costs and limitations, just like any other power source. If fusion is cheaper and more versatile, then it will displace solar.

However. . . Honestly, I think it's kind of stupid to pit solar and nuclear fusion against one another. Of all the possible replacements for fossil fuels, the only ones that seem to be truly scalable enough to fill our global energy are nuclear (fission or fusion) and solar. (And maybe possibly geothermal, though that's not really proven.) Solar and fusion have very different profiles, and will almost certainly prove to be complimentary technologies rather than head-to-head rivals.

Nuclear isn't electricity... nuclear is heat... that heat must be converted into electricity... that conversion costs $$$. If solar BOS drops below ~$1/w it will be cheaper to turn sunlight into electricity with photovoltaics than heat into electricity with a thermal plant. There's a reason that Ivanpah will likely be the last thermal solar plant.

The only type of nuclear that will be able to compete will be nuclear that isn't thermal... a technology that currently only exists on paper.

Here's an interesting article outlining why solar + wind and generators costing >$5/w generally don't mix...

When you need a generator to fill in power gaps... it's gotta be cheap.

 

[TheTalkingMule]

As fans of solar, we can all agree that just because something is slightly more expensive doesn't mean it has no place in the mix. If we can get safe reliable fusion up and running it's certainly worth slapping some turbines on top of it and having a carbon free baseload.

These smaller scale fusion mini-plants people keep dreaming up would be the perfect compliment to solar/wind within a locally managed micro-grid. At this point all our options are theoretically affordable, so lets start moving towards the optimal longterm mix.

 

[nwdiver]

As fans of solar, we can all agree that just because something is slightly more expensive doesn't mean it has no place in the mix. If we can get safe reliable fusion up and running it's certainly worth slapping some turbines on top of it and having a carbon free baseload.

These smaller scale fusion mini-plants people keep dreaming up would be the perfect compliment to solar/wind within a locally managed micro-grid. At this point all our options are theoretically affordable, so lets start moving towards the optimal longterm mix.

Agreed; Key word there being 'slightly'. So it needs to be able to produce power for <$0.05/kWh even with a capacity factor of ~50%. So the upper price limit is gonna run ~$2/w... which is about the cost of a steam plant... that doesn't leave a lot left for the cost of the fusion plant...

The economic argument for electricity derived from a heat source is somewhat like the physics argument for solar panels on a car... the numbers simply ain't there to make it workable.

 

[Johan]

Dense plasma focus fusion using boron fuel produces electricity, not heat. No need for a turbine.

 

[TheTalkingMule]

Agreed; Key word there being 'slightly'. So it needs to be able to produce power for <$0.05/kWh even with a capacity factor of ~50%. So the upper price limit is gonna run ~$2/w... which is about the cost of a steam plant... that doesn't leave a lot left for the cost of the fusion plant...

The economic argument for electricity derived from a heat source is somewhat like the physics argument for solar panels on a car... the numbers simply ain't there to make it workable.

I don't know if that's the case. If Germany could install safe reliable mini-fusion reactors for double that, they'd do it in a heartbeat. And I'm not even sure there is a price per kWh that should dissuade people/governments from exploring the ability to provide sufficient baseload with zero emissions. We're headed for Star Trek society anyway, do we really care about cost once energy can me made "free"?

 

[ScepticMatt]

Dense plasma focus fusion using boron fuel produces electricity, not heat. No need for a turbine.

Let's get DT working first, before talking about the much harder PB11 (Bremstrahlung losses etc.)

 

[Johan]

Let's get DT working first, before talking about the much harder PB11 (Bremstrahlung losses etc.)

LPP are not going the detour which is deuterium-tritium fusion with thermal yield. They're aiming to go straight to hydrogen-boron fuel and to do aneutronic fusion that produces charged electrons (electricity) and X-ray radiation which will be directly converted in to electricity through the photoelectric effect (basically like solar panels only very different wavelengths than visible light).

FUSION | DPF Device

Basically my view is forget Tokamak design; forget trying to control the plasma so much. Instead let the plasmoid do what it does naturally without being guided by engineered artificial magnetic fields and harness that energy instead. Like what happens in a supernova only on a much, much smaller scale.

LLP's approach seems to me the far most likely to succeed.

 

[ScepticMatt]

LPP are not going the detour which is deuterium-tritium fusion with thermal yield. They're aiming to go straight to hydrogen-boron fuel and to do aneutronic fusion that produces charged electrons (electricity) and X-ray radiation which will be directly converted in to electricity through the photoelectric effect (basically like solar panels only very different wavelengths than visible light).

I heard about LPP and other various other non-Tokamak designs. That they are trying to capture the bremsstrahlung is news to me, though. Got a link?

 

[Johan]

I heard about LPP and other various other non-Tokamak designs. That they are trying to capture the bremsstrahlung is news to me, though. Got a link?

Yeah, in my post

Aneutronic is the other big advantage: no ionizing radiation, not nearly as destructive to the containment material.

 

[ScepticMatt]

Yeah, in my post

Only a rather vague statement sadly. It's total system efficiency remains to be seen.

Aneutronic is the other big advantage: no ionizing radiation, not nearly as destructive to the containment material.

The bremsstrahlung gamma rays are ionizing radiation. Neutrons have no net charge, which is why it is only a indirectly ionizing radiation
(e.g. neutron absorption resulting in secondary gamma emission from beta decay). I guess neutron activation is what you are referring to.

 

[Johan]

Only a rather vague statement sadly. It's total system efficiency remains to be seen.

The bremsstrahlung gamma rays are ionizing radiation. Neutrons have no net charge, which is why it is only a indirectly ionizing radiation
(e.g. neutron absorption resulting in secondary gamma emission from beta decay). I guess neutron activation is what you are referring to.

You're correct about what I meant with regards to the neutrons. In the proposed design from LPP all the gamma rays ("X-rays") are captured with layers of different photovoltaic materials, covering the frequency spectrum emitted, directly surrounding the reactor core (and hence converted directly to electricity). Thus there won't be any ionization occurring externally to the reactor (which is what really matters I suppose). One alternative application is to allow instead for massive output of x-rays from the device, and use it for x-ray imaging of for example inorganic structures such as bridges and buildings.

LPP are doing hands-on research, it's quite a bit more than vague statements. I'm happy to point you to a thread here on TMC with more detail on how far they've actually come in their research. I suggest start with the video presentation in the post by Dutchie:

LPP questions/discussion - Page 17

 

[nwdiver]

I agree that LPP is one of the few technologies where the economic numbers 'could' be workable...

Hard to say since no working prototype currently exists. I'm certainly not opposed to researching other options but I am a bit wary. Our back is to the wall here... we've got less than 30 years to really turn our energy infrastructure around and the longer this transition takes the greater the risk. My parents generation really set us up for failure... I don't think I'll ever forgive them for that.

Fusion is a gamble... we need to treat it like a gamble. It might payoff... it might payoff too late... it might be impossible to scale commercially. What percentage of your savings would you be comfortable spending on lottery tickets? Our society needs to have a similar investment ratio of Fusion R&D to Solar/Wind/Storage.

Perhaps a good real world example is WW2; The US spent $2B on the manhattan project... somewhat of a gamble but a gamble that had the backing of most of the scientific community in the world. But... we didn't stop building the stuff we knew worked. While we were investing ~$2B researching the super-weapon that could end the war we were spending >$300B on tanks, ships and planes.

 

[tonybelding]

For those wanting a lot more technical details about the ARC reactor, check this:

Next Big Future: Bizarre nuclear fusion reactor in 5 years headline from Treehugger but claimed better reactor based on superconductors not expected to be ready for ten years

 

[Dutchie]

Great overview of current situation

Next Big Future: Lockheed Martin Compact Fusion Reactor Update with Video of Technical Presentation made at Princeton