His graph assumed continuous exponential growth in deployment. In reality, deployment of solar in 2018 (97.4 GWdc) was slightly less than in 2017 (97.8 GWdc).
> But anyway, is that really a talk saying we should invest in fusion because solar won't scale fast enough?
First Light Fusion, Commonwealth Fusion Systems, and Tokamak Energy are all aiming at net energy by 2025 and grid-connected power by 2030. Lockheed Martin wants power plants at scale in the 2020s, with designs small enough to power aircraft (though their approach is more novel than CFS/TE physically). All four of companies have cost-effective designs radically more economically feasible than the JET/ITER/DEMO pathway of old.
There's no magic to fusion, it's just a matter of finding a way to do it economically.
Company goals, and $5, will get you a mocha grande at Starbucks.
None of those have any real chance of being commercial viable. The tokamak approaches, in particular, are both much larger than, and much more complex than, a fission reactor of equal power output. Yes, they are more cost effective than ITER. Only 40x lower power density vs. 400x lower. Yay?
NuScale is about 3x3x20m for 60 MWe. SPARC is about 4x4x4m (?) for about 50-100 MWe; that only includes the reactor proper, but the rest should be no less compact than any other plant.
I'm talking about the power density of the primary reactor vessel (the part in a PWR that has things too radioactive for hands-on maintenance). In current PWRs, that's about 20 MW/m^3, vs. about 0.5 MW/m^3 for ARC.
OK... so? This seems like a pretty meaningless statistic. The reactor core for a magnetic confinement fusion reactor is pretty much the only meaningful radioactive waste from the process, and within 50 years it turns itself into low-level waste. This isn't a zero quantity of waste, but it's comparatively trivial.
Even if you have to replace a piece, you just unfold, crane the old one out, and crane the new one in.
It's meaningful because cost is related to size and complexity.
The core of a fission reactor of a given power output should be smaller and simpler than that of a fusion reactor. As a result, it should be much cheaper, and also more reliable.
The parts outside will be very similar (even fusion reactors will require containment buildings, due to the very large amounts of tritium involved).
Fusion designs go even further and imagine operating at high temperature than LWRs. But this also drives up cost; materials problems rapidly become worse as temperatures increase. High temperature fission reactors have never caught on, for this reason.
It follows that fusion power plants will not be cheaper than fission power plants.
People have priced these already, it's competitive.
Fusion requires fewer safeguards, less insurance, and is more repairable than fission. Reliability isn't an issue just because it's 4m³.
Why would fusion reactors need ‘very large’ tritium supplies? SPARC would use, what, <100g/day? And it would generate excess, so they wouldn't need a stockpile. Tritium isn't even particularly dangerous; it goes away on its own, and doesn't stick around in biological systems.
> People have priced these already, it's competitive.
I don't believe these estimates, either in the input data or the methodology. They are basically an exercise in "how optimistic can I be before no one believes me". It's not as if any shenanigans in them will be checked against reality anytime soon. They aren't a good counter to the simple argument of "larger, more complex, and made of more exotic materials implies more expensive."
But in any case, let's look at ARC, shall we? The cost comes to $29/W(e), very much higher than fission reactors. They have to resort to "and the Nth of a kind plant will be a factor of K cheaper". Never mind that the closest analogy, nuclear fission plants, has not shown good experience effects.
About tritium: I don't think you grasp how problematic this material is. The amount of tritium consumed in a 1 GW(e) fusion plant in a year would be enough to contaminate 2 months worth of the flow of the Mississippi River, at New Orleans, above the legal limit for drinking water. Confinement of tritium is going to have to be damned near perfect for a DT reactor to be acceptable.
> But anyway, is that really a talk saying we should invest in fusion because solar won't scale fast enough?
Yes.