The 1000 miles road starts with a first step, and it's not like we can't pursue several approaches at once. People like grandparent poster suggest us drop everything and concentrate on the idea he likes best. That is a very bad and harmful idea.

No one is saying we shouldn't invest in exploring fusion. But we shouldn't sit on our hands on the interim. We need to invest heavily in the best alternative resource available right now till such time as fusion is a viable alternative to solar.

Keep in mind horses and cars co-existed as mainstream transportation choices right up till the end of world war 2.

> No one is saying we shouldn't invest in exploring fusion.

Actually, jhallenworld's comment was saying exactly this: "We should put more resources into storage now, fusion can wait".

That's what prompted my response about horses in the first place. Analogy is apt, because first engines were wildly inefficient compared to horses, yet, if people back then would never pursue them, we would never have eventual progress. So no, while we should invest in storage, fusion CAN NOT wait.

We aren’t. MIT’s SPARC Tokamak design could be ready for commercialization by a decade. Less time than completing a high speed rail project in the US.

The word "could" is doing a lot of work, there.

And how many times have we heard the phrase "a decade" in this field?

Kind of a lazy comment. There has been substantial progress with the latest development from NIF as well as SPARC demonstrating a magnet section that would enable ITER at a much smaller scale using fundamentally superior superconducting technology With NIF’s latest result, we’re no longer just generating smoke from rubbing sticks together, now we got a flame.

That’s a substantial, qualitative change in the state of the art of fusion technology. Now we need to do it dozens of times per second and make steam from it, while using efficient lasers and breeding tritium from the lithium jacket.

Works kind of like the EUV light sources TSMC uses to make the highest end computer chips, except a fuel pellet instead of a drop of tin. Like so: https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy

The mininum viable Qplasma would be in the neighborhood of 100.[1] Fusion may get competitive for electricity generation with a Qtotal > 500.[2]

1. Sabine Hossenfelder, How Close Is Nuclear Fusion?, https://www.youtube.com/watch?v=LJ4W1g-6JiY&t=8s

2. Nicholas Hawker, A simplified economic model for inertial fusion, https://pubmed.ncbi.nlm.nih.gov/33040650/

NIF's target cost millions of dollars to make. It produced 1.3MJ of energy, which is (generously) worth about a penny.

SPARC/ARC would enable a tokamak at a smaller scale (and self-sustaining from bootstrap current, most likely) but ITER is so far out of the running that something can be much better than it and still not be practical. ITER's gross fusion power density is 400x worse than a PWR's reactor vessel; ARC would only be 40x worse.

Call me with the second and third commercial reactors are completed. That's when we'll have an idea of the real world viability, including how to scale and deal with production concerns.

So we shouldn’t be investing in developing nuclear fusion power until after it’s proven and commercialized? How does that work?

No, I'm saying don't sit around talking about how this will be ready for commercial deployment in less than ten years until after it has been demonstrated to actually work in a production environment.

The first commercial production system will be an alpha build. The second and thirds are betas. It's only after those are completed that there's enough information to make commercial plans.

As of now, this system the GP is talking about hasn't even been built yet and won't be operational until at least 2025. And even when it is built, it is just a lab experiment designed to run in 10 second bursts. There are numerous more steps after this design phase before we get to commercial application.

Ten years is a pipe-dream for commercial application.

I'm excited to see progress in this field. But we are doing it a huge disservice by spreading misinformation about it. There are still a lot of problems to be solved before these are ready for prime time. And these problems will require a lot more funding to solve. If people sit around and talk about how this will be ready to go in 10 years, then who is going to want to fund it into year 11?

Scientific funding is directed largely by politicians. And there are many, many political opponents to science in our current Congress. Giving them ammo in the form of empty promises doesn't do advocates for fusion energy any good.

The honest answer is, we still don't know if tokamak will ever make for a viable commercial power plant. Best can be said is that it has been demonstrated to produce net positive energy for short periods of time, and that there is confidence that improvements can be made. That's it. The viability of commercial application has yet to be demonstrated and may never happen.

Its power density will only be 40 times worse than a fission reactor, and made with steel operating at much closer to its strength limit (safety factor of 1.5 for the ARC design, I think, vs. at least 3.5 for steel pressure vessels in the ASME code). There is no way this will be cheaper than fission power plants, and they are already not competitive.

In many areas nowadays, solar is the cheapest source of energy bar none.

Now, suppose you live in one of those areas. Two questions:

1) What year was solar first ready for commercialization? 2) Would you ever consider that year's solar tech outside of extremely niche applications?