Lawrence Livermore claims a milestone in laser fusion

There is no reasonably foreseeable future with fusion as part of the electricity grid. Even if we got fantastically lucky and were able to build a practical (magnetic or inertial) reactor in 50 years, by that time improvements in energy storage and transmission technologies will have allowed renewable energy to dominate, and no government would be crazy enough to permit it to be built.

http://progressive.org/op-eds/let-cut-our-losses-on-fusion-e...

The whole NIF building has the ability to switch modes between classified and unclassified. They wouldn't have gone through the trouble of making this a toggleable feature on the building if they weren't actively using it for both.

Oh, but then there's this part:

>> Further experiments will require the manufacture of additional fuel capsules and hohlraums. These may not be ready until at least October, Herrmann says. The nanocrystalline diamond-coated capsule that was imploded in this month’s event took six months to grow at General Atomics, which has long worked with LLNL on fabricating capsules. The spheres have to be polished and the core’s interior etched with tools inserted through a 2-micron-diameter hole drilled into it. The tritium–deuterium mixture is injected through a tiny fill tube just prior to the shot.

EDIT: on funding, this[0] image shows what is neccessary and the level we actually funded. It's been around for a while but it may prove informative for the uninitiated.

[0]https://i.imgur.com/3vYLQmm.png

Not to downplay the achievement of the article or the innovation in fusion physics and engineering in general, just a bit of context for the timescales.

The part after that, was it a typo? :)

Awaiting the downvotes but it's true.

Alternatively it's about the amount of energy to raise 4 L of water from room temperature to boiling.

I suspect that's always been a funding fig leaf. The nuclear stockpile stewardship claim is highly dubious.

Not that I mind. There are worse things diverted DOD money has been squandered on.

In a simpler way of looking at it, (1) what is the source of the energy of solar/wind? (2) how much land and materials are required to linearly increase power production?

There is a finite amount of space and resources on the planet to continue to scale power production with humanities consumption.

Fusion, preferably MCF/tokamaks in the style of smaller sized ones like SPARC @ MIT and less like ITER (behemoths that take decades to build and maintain) offer two things (1) the fuel is comprised of the most common elements in the universe, (2) power per square foot is much greater than solar or wind... And bonus (3) once developed it should in theory require less material per watt generated. And less materials mean less processing and fabrication which in turn reduces the environmental impact on the planet.

You seem to want to halt all further research into alternative energy and settle with the current state of our solar/wind capabilities, which is strange.

We can do both.

Seasonal variation with solar is a bit of a bummer. If we need to fully electrify everything, (Transport and heating) then winter will be a problem. Either we massively overprovision solar in order to still have heat on the shortest day of the year, or we run thousand mile cross-country transmission lines and enormous battery banks.

Even so, the economics are such that heavy industry might become a seasonal job. Right now we run aluminum smelters 24/7 because baseload power is fairly consistent, but if solar power is free in July but dear in January you might see multi-month shutdowns. This gives headaches to central planners, and makes them inclined to pour billions into fusion if it can preserve some of the status quo.

If fusion works out, it could be used to make up the difference when the sun isn't shining and the wind isn't blowing (though if we eventually get high-capacity transcontinental HVDC lines to buy and sell power from practically anywhere or batteries become really cheap, that becomes less of a concern).

Fusion would also would require far less land, and some people object to having a landscape covered in windmills and solar panels.

Fusion might be useful in places where renewables are less practical, like on ships. Naval vessels might conceivably replace fission reactors with fusion. If they're safe and relatively simple to run, you might even see them on civilian ships. Or you could have fusion reactors in remote places, like floating on a buoy in the middle of the ocean, to serve as a charging station for battery-powered ships.

Fusion may be useful for establishing a human foothold outside of Earth. For instance, methane production on Mars (for rocket fuel) will require enormous amounts of energy, which could be supplied by a fusion reactor. (A fission reactor would perhaps work just as well, but there are legitimate reasons why people get nervous about launching hazardous materials into space on a rocket that might blow up before it achieves escape velocity.)

We might also begin engaging in projects that require enormous amounts of energy. For instance, if certain CO2 absorption strategies are energy-intensive, and we can't practically generate that amount of energy from renewables.

At this point, we really don't know if it'll work much less what the practical limitations will be, so perhaps the best we can do is say "if a fusion reactor can produce X amount of energy and weighs Y tons and requires such-and-such amount of cooling and requires an overhaul once every N months at a cost of D dollars, we might want to use it in these applications".

So the footprint of fusion would be a lot smaller.

Also for the same reason deployment would be faster allowing a faster phase out of fossil fuels.

The Earth has an insane amount of material. It's the greatest tragedy that life occupies only the thinnest film on the thinnest edge of the Earth. The more we can make use of the full potential of the Earth, the more life there can be. It's a waste to just leave all that matter buried, doing nothing more than providing gravity.

We need to solve the energy usage problem, not its production.

More energy means more solutions. Think carbon sequestration, vertical farming, building megastructures to combat sea level rise, climate engineering, or even just pumping heat into space as infrared.

We are indeed in a climate crisis, but 85% of the crisis is that people have given up on the future and just want to panic.

Good luck with that.

The maybe-tldr version: we can make fusion occur, but it currently (well, until today) takes more energy to make it happen than we get out. We have good models that predict this relationship, and it mostly boils down to maximizing the "triple product": temperature times plasma density times confinement time. The two most popular broad approaches are "magnetic confinement" (holding a plasma for awhile with magnetic fields) and "inertial confinement" (taking a capsule and rapidly mechanically compressing it, with lasers or a railgun or something, which is what this NIF thing is), and each chooses to maximize the triple product by leaning on different multiplicands -- inertial confinement is much shorter time, but higher density as compared to magnetic. For both, the other factor is plasma instabilities: plasmas don't like to behave, and like to leak out of their enclosures or not maintain the shapes you want them to, and lots of research seems to be about controlling those.

Beyond that, what the challenges are depend on the approach you choose. For inertial, bumping up the triple product seems to be mostly about building bigger and more powerful systems, and managing plasma instabilities. NIF also uses an "indirect" approach where the lasers get (inefficiently) turned into X-rays which then compress the plasma, and "direct" inertial fusion has even bigger plasma instability problems to solve.

For magnetic, the most mature technologies, tokamaks, have well-understood properties in terms of plasma management, and the main still-to-do work had been thought to just be making the machines bigger, which is what ITER is doing, but the recent change is the development of high-temperature superconducting magnets, which might allow for much higher-strength magnetic fields, which would allow for success with smaller machines (that's what, e.g., Commonwealth Fusion, is pursuing). In either case, the goal is just bumping up the triple product until we get to net gain. Other magnetic approaches (stellarators, etc.) are probably at a somewhat-earlier stage of understanding plasma behavior.

For both inertial and magnetic, there will also be development needed after net energy gain to get enough of a gain factor that the economics actually make sense and things can be mass-produced (current thinking is that to actually be economical, we need to get to ~30x energy out compared to what went in), and also likely some materials-science innovations needed to keep the reactor from wearing out due to high neutron flux, and possibly some work producing tritium, the likely fuel, from lithium.

Beyond those MCF and ICF, there are also a bunch of other less-mature technologies that startups are exploring that might also produce good results, and (the founders think) might do so more efficiently than the big approaches, but they're not as far along, and the work still to do is more basic-science-ish. This would be things like Z-pinch, fuel cycles other than deuterium-tritium, etc. etc.

A physicist friend from NSF told me once that $50 billion would be about right.