Fusion energy breakthrough by US scientists boosts clean power hopes

First-ever net energy gain from fusion raises hopes for zero-carbon alternative.

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[rojcowles]

Great news and exciting but not entirely surprising as far as I can tell getting to break even or significant net gain with terrestrial, controlled, nuclear fusion so a power plant could provide net energy to the electricity grid has been a question of engineering rather than physics for a few years now.

Brutally hard engineering challenges to be fair and doubly so in that any solutions that would achieve fusion conditions on demand for power generation also have to be affordable so that the capital cost of the plant, fuel, running costs, safety and decommissioning mean that a MWh from a fusion plant is at least somewhat price competitive with natural gas, solar/wind+storage, hydro, coal or fission and might still require government subsidies as a low carbon energy source to get the market for fusion providers / operators somewhat de-risked and established.

Still news like this might spur further investment in the current crop of commercial fusion companies, even if they are pursuing alternate approaches to inertial confinement, which makes me happy and could improve the chances of someday seeing compact fusion reactors rolling off shipyard like production lines to go into power plants or cargo ships and slowly ease civilization away from burning giga-tons of carbon based stuff annually to make electricity.

Also looking forward to pointing to my EV and saying to someone "See? It's fusion powered just like that DeLorean" though might be a much different car than my current Leaf before that happens.

 

[rojcowles]

probably not with inertial fusion, or at most generous not just inertial fusion, however, it is useful in informing how much input energy is needed to realistically achieve a net positive reaction. But yeah the NIF is basically how the US is able to continue nuclear weapons development post Nuclear Test Ban Treaty

First Light Fusion has an inertial fusion approach where they hit a plastic target containing fusion fuel with a hypervelocity projectile as it falls into a chamber with a deluge of liquid lithium metal and repeat this process several times a second. The shockwave travelling through the target and the fuel after the impact should be sufficient to trigger fusion per their modelling and simulation and once the engineering is worked out the energy released from the fusion event would be absorbed by the already liquid lithium and then presumably this extra heat energy in the lithium is exchanged with a regular steam generation loop and the balance of plant looks very similar to a current nuclear or burny-stuff power station.

Having said that I really don't see the giant laser NIF approach to fusion every being commercially viable, then again I think its main role is validating nuclear weapon designs without violating any treaties so maybe not a big surprise.

 

[rojcowles]

The hard problems are making the failure modes "safe", making the "default" energy generation (rather than practically needing to hand-force every last molecule into just the right place), and then there's the neutron bombardment utterly ruining the material the fusion generator is made out of. If the whole shebang's gotta be replaced every couple years, and we scale that up worldwide, well that's a lot of resources. That said, it's certainly not nearly as much as what goes into all our much dirtier energy generating systems. Speaking of, while some fusion materials result in non-radioactive byproducts, others don't. Unfortunately the ones that have more harmful byproducts tend to generate more energy and use less rare materials to start with.

I'm kinda... going off an amalgam of barely remembered fusion articles I've read over the decades so forgive me if I get any of the details wrong. There's a reason these things are joked about as "eternally ten years away", fusion has never been as "set it and forget it" style of energy production. Still, this is a big step. We just don't know high the staircase is yet. In the meantime, the transition to wind, solar, thermal, and hydro should continue apace. Act like fusion isn't available for now, until it is.

True, starting and running a fusion plant cannot be significantly more difficult than a current thermal power plant otherwise it'll only ever be a scientific or technical curiosity, though to be fair even regular power stations have their own operational challenges going safely from a cold state to fully running.

One of the other hard problems that people who go to fusion conferences ... or are sad enough to listen to the recordings of the conference sessions afterwards ... are aware of is logistics and supply chain scaling for fusion specific materials. It may be well and good to get to break even but if you need a team of PhDs to spend months lovingly hand crafting every fuel pellet and the entire global supply of Unobtanium for the first demo plant its not going to be world changing.

Things like bulk Deuterium, Tritium, Boron or Helium3 for fuel, tons of pure Lithium for breeder blankets to capture neutrons for Tritium production, exotic alloys or ceramics to withstand the intense neutron bombardment on the plasma facing walls and the diverters, etc, etc. Not insurmountable to be fair but as some of these supply chains don't exist right now it might take a while for a competitive market to spin up.

There's also the bureaucratic challenges of licensing and permitting fusion plants as distinct from fission plants and safe transport of radioactive fusion materials to a power plant and from a plant after its decommissioned, and these may be harder challenges than the engineering.

Also I have to wonder if even if we meet the optimistic projections of a few of the commercial companies like Commonwealth Fusion Systems or Tokamak Energy and get a demo plant generating net electricity and feeding that to the grid by the early/mid 2030's would the scale out of wind and solar with ever increasing amounts of grid scale electricity storage have achieved the sort of levels to provide affordable 24/7/365 baseload power and there just won't be a market for fusion power plants?

 

[rojcowles]

It won't have to compete with solar and wind. Solar and wind alone are not going to be what powers the grid. Likely where Fusion will have a home is in helping to provide the last few percent of power to the grid, which is going to cost significantly more per kW-hr than the first 95% of production.

Huh, hadn't thought of that. Thanks!

Did read an article that suggested that space based solar could be economically viable, despite the sky high capital costs, horrific maintenance challenges for the space based components and massive conversion inefficiencies, if it also is viewed as the way to close the gap on the final few percentage points of demand that can't be met through renewables+storage so we can eventually decommission every thermal power plant.

 

[rojcowles]

It could but that is currently science fiction. In fact that is how the reactors on the Rcoinante in the TV show The Expanse work as evident by the episode where it stopped working.

Power collection is either direct charged particle collection (even more scifi) or using the thermal output to heat a transfer fluid to turn a turbine. People often say "steam powered" but it wouldn't necessarily have to be steam there are other concepts for high temperature closed cycle turbines.

This diagram is for a helium cooled fission reactor but the same concept could be used with a fusion heat source as well.

Of course both those problems are really only problems to solve once you can reach a Q of 25+ (that is 25 times the output energy from fusion compared to the input energy) until then it is like designing the interior layout of a moon shuttle before you have built a rocket.

Prob ninja'd up-thread but ...

Something like the First Light Fusion's "Projectile Fusion" design?


View: https://www.youtube.com/watch?v=aW4eufacf-8


Also just saw a press release from Tokamak Energy congratulating the NIF result stating that their planned ST-1E machine, to be built after the not yet built ST-80 research machine, is aiming for a Q of 25 and maybe, if they aren't being too starry eyed optimistic, have it achieve initial operation / net electricity to the grid in the mid 2030s. Hope they are right but won't be at all surprised if that proves to be ahhh "aspirational" and the eventual date is significantly later.

Sigh ... what a time to be a fusion groupie ...