We are spending a relatively pitiful amount of money on fusion power research. The US has spent $29B TOTAL in 2010 dollars from the 1950s through 2010. (I couldn't easily find global numbers, but I can't imagine it's more than an order of magnitude higher)

Some other numbers for comparison:

NASA's current ANNUAL budget is $19B. [1] The BP oil spill cost $40B. [2] "A 2016 IMF study estimated that global fossil fuel subsidies were $5.3 trillion in 2015, which represents 6.5% of global GDP." [3] The US alone spent $600B on fossil fuel subsidies in 2015. [3]

>It's not obvious that throwing more money at the problem is going to change this.

This is true, but we haven't funded it enough. The potential upside is insane. We aren't funding research accordingly.

[1] https://www.quora.com/How-much-money-is-being-spent-on-resea...

[2] http://www.fusionenergyleague.org/index.php/blog/article/hav...

[3] https://en.wikipedia.org/wiki/Energy_subsidies

>>It's not obvious that throwing more money at the problem is going to change this.

>This is true, but we haven't funded it enough. The potential upside is insane. We aren't funding research accordingly.

How much money do you propose we throw at it then because even fission isn't profitable these days and that is something we know how to do. While I agree that it is worth something to pursue, wind/solar + batteries + smart grid are a way better investment these days since we cannot even produce a fusion reactor that is net positive in energy let alone economical.

Just for the record, you don't re-create stellar-core conditions with earth-bound fusion devices: We don't have the means, and the yield would suck.

Now, it is true that there's still fundamental research to be done until energy production via nuclear fusion becomes a reality, but we're reasonably confident that we could make the conventional approaches work.

However, that research is Big Science, and there's no political will to fund it properly (the graph that people like to cite is https://commons.wikimedia.org/wiki/File:U.S._historical_fusi... ). ITER suffered from this as well, and W7-X basically only exists because German reunification happened, and the German government was looking for a big science project - any project - they could leverage to funnel money into East Germany. The plans for W7-X just happened to be ready at the right time.

>>> However, that research is Big Science,

Not all of it. The big science approach is a function of "pure" fusion research done from the assumption that containment/ignition only comes from magnetic fields and particle collisions. Some are approaching it from different directions, even using physical forces to trigger ignition (ie slamming the hydrogen with a big hammer). This isn't crazy stuff, just a more practical approach from people who see the problems from a different perspective.

https://en.wikipedia.org/wiki/General_Fusion

https://www.canadianbusiness.com/technology-news/crazy-geniu...

"At the centre will be a sphere, three metres in diameter, inside which molten lead swirls at high speed creating a vacuum, or vortex, in the middle. Arrayed around it will be 200 to 300 pistons, each the size of a cannon. Firing in perfect harmony, they will create an acoustic wave that collapses the vortex at the very moment a plasma injector shoots hydrogen isotopes, the nuclear fuel, into it. If General Fusion has its physics right, the heat and pressure will ignite a fusion reaction that spins off countless neutrons which will heat the lead even more. Pumped through a heat exchanger, that hot lead will help generate steam just like a conventional thermal power plant."

General Fusion changed their plan last year. The acoustic compression scheme, and the use of a spheromak plasma, are out. They discovered they have to limit the magnetic field to about 100T or else the induced currents start vaporizing the surface of the imploding liquid metal. This would be a disaster, as the metal vapor would have poor electrical conductivity and would penetrate into the plasma.

Confinement in the spheromak was also unacceptable; fast electrons were lost too easily from the edge, causing too much cooling.

Instead, the new scheme compresses more slowly, and compresses a spherical tokamak plasma. This scheme will have a solid post running down the center of the plasma, and the metal will implode from the sides at lower speed. The burn will take about 1 millisecond.

I am skeptical of this approach, since the center post will be exposed to extreme conditions (average neutron fluence two order of magnitude higher than in conventional fusion reactor designs) without a thick layer of liquid metal to shield it. The non-acoustic compression scheme also means the reactor vessel will have to withstand extreme pressure.

Hence my qualifier 'conventional approaches'. I wish those working on alternative approaches the best of luck, and some of the experiments look like a lot of fun (they get to blow things up - I've seen videos where plastering was raining from the ceiling of the control room ;)).

I'd say that the "conventional" approach for triggering fusion is physical. We've been triggering fusion in nuclear weapons for many years and the physicalities of it are very well understood. What general fusion is doing is essentially a non-destructive nuclear secondary. Triggering fusion with magnets, without moving parts, is imho the unconventional way of getting to fusion. It is only conventional in comparison to fusion research. The practical users of fusion (the armed forces) don't use magnets.

>> and W7-X basically only exists because German reunification happened, and the German government was looking for a big science project - any project - they could leverage to funnel money into East Germany

That's the first time I've heard that. Brilliant!

It's wrong, though.

Well, it's wrong insofar that the federal government wasn't actively looking for projects to fund and then miraculously discovered W7-X in a drawer. Rather, W7-X people were looking for funding and shopping for locations, but failed to secure it until they stumbled onto this particular angle to push. It's no coincidence that a new branch of the Max Planck Institute was established in Greifswald, whereas all previous work was done in Garchingen.

At least, that's the story I've been told by one of the current top W7-X people over a glass of beer, though the main topic at the time was that the movers and shakers behind such big projects might not see them to completion due to retirement or even death.

> However, that research is Big Science

Some of the progress in recent years is from the development of ideas that can be tried at much smaller scales, like the ST40:

https://www.youtube.com/watch?v=Cjzok6h2-xA

This is something that spherical tokamak research has been hammering away at for years:

https://en.wikipedia.org/wiki/Spherical_tokamak

>Just for the record, you don't re-create stellar-core conditions with earth-bound fusion devices: We don't have the means, and the yield would suck.

See Inertial Confinement Fusion, The NIF, High-Energy-Density Physics, etc.

> It's not obvious that throwing more money at the problem is going to change this. After all, fusion research has been funded in some form or another since the 1950s.

That's not very long. The first liquid-fueled rocket was in 1914, and the moon landing wasn't until 1969, and even that was only possible with very high levels of funding far beyond what's invested in fusion power today. Babbage built the Difference Engine in 1822 and conceived of the Analytic Engine in 1837, leaving skeptics dismissing the potential of computers for 150 years. Leonardo da Vinci sketched a helicopter in 1480, almost 500 years before one could actually be constructed. Gunpowder was invented probably before the year 1000 and took over 700 years after that to render pikes obsolete.

Now, it's entirely possible that there's some other limitation holding us back from fusion, just as the lack of internal combustion engines or diodes held us back from helicopters or computers. But I think we've done enough work so far that we'd be able to tell if we were running into something like that. As it stands, I think we're roughly in the place rocketry was before WWII--we have an idea of how to do it, and we don't know if it'll go to the Moon or not, but the only way to find out for sure is to try, and that's pretty expensive and might take awhile.

We do know there are inherent problems with fusion, particularly DT fusion. In fact, we've known for 35 years or more. Even if the plasma physics issues are magically solved, fusion has grave engineering obstacles.

http://www.askmar.com/Robert%20Bussard/The%20Trouble%20With%...

https://pure.mpg.de/rest/items/item_2131865/component/file_2...

It's interesting examining the recent efforts, public and private, in light of these venerable critiques.

The total since research started is somewhere between $25bn and $50bn.

In the US alone, oil subsidies are >$400bn a year.

Here’s an article - about the same amount, annualised, is spent on Halloween costumes for pets.

http://www.fusionenergyleague.org/index.php/blog/article/hav...

Not to mention the total expenditure on fusion weapons.

In 1976 a plan for how much funding over how much time was made to get fusion ready. This graph shows the possible paths, as well as the actual level of funding, and is a great explanation for why fusion seems to always be x decades away: https://commons.wikimedia.org/wiki/File:U.S._historical_fusi...

This graph precisely illustrates my point. Let's conservatively posit that a workable fusion reactor is worth $2 trillion; the world spends many multiples of this on energy each year. The cost of acquiring fusion, according to its advocates, is equal to the integral of any one of the curves on this graph, which looks to be on the order of ~$100b. This is well within the range of investment attainable by private sources, just look at pharma. In other words, if fusion advocates are to be believed, the market is failing to the tune of few trillion dollars, roughly the GDP of the United Kingdom, and has been for decades. Now, markets are not necessarily efficient, but is this a believable scenario? I claim no.

Fusion research is chronically underfunded. We actually have made surprising progress despite basically not funding research at all.

I'm a physicist by training working as a software engineer at one of the large tech companies. I have multiple physics friends doing the same.

We'd gladly be working on fusion (or other physics stuff) but our present jobs pay much better.

More money, and better pay for hard science careers, actually would make a difference.

If fusion research funding got 1'000 dollars a year, we wouldn't have 1'000'000 dollars worth of research after 1000 years. Just as there are diminishing returns after throwing so much money at a problem, throwing too little means that progress will halt and we get stuck in a local minimum because we need a bigger cash infusion to get over the hump.