Based on a HN recommendation, I read this book: https://www.amazon.co.uk/Future-Fusion-Energy-Popular-Scienc...
The authors argue that ITER will get there and it's a matter of time, funding, and politics. SPARC might be able to get there around roughly the same time. Neither will be hooked up to the grid, but they will demonstrate the tech needed to make a viable fusion power plant. Unfortunately none of the other exciting fusion projects out there will be able to get off the ground due to fairly fundamental limitations.
If you ignore any tedious jokes about when fusion power will be ready, and assume it will be ready in a few decades, it's still a process that converts reasonable quantities of seawater into power, with no CO2 emissions, and is relatively safe compared to fission.
It won't be ready in time to reduce emissions enough to prevent catastrophic climate change. However, it can be ready soon enough to power the devices we'll need to sequester CO2 from the atmosphere once we've reduced our emissions to the point of diminishing returns.
After the concept has been demonstrated, there's plenty of scope for improvement which will make it better and cheaper. On the other hand, the price of oil will increase as emissions taxes are introduced (I hesitate to say that we'll run out of reserves).
There's a lot more mileage in fission technology that what's commonly deployed for power, but the new types of reactors needed make it far easier to produce weapons(). Also, although fission technology is mature and safe, the human factors around it are not, which will still lead to accidents, contamination, and deliberate theft.
We should know without a doubt whether it is workable by 2050, perhaps before then.
I strongly recommend the book "The Future of Fusion Energy" as a good summary of the current state of the field. It's written by two fusion researchers and is legit (I have a Master's in Physics myself and almost did a Plasma Physics PhD so I am somewhat familiar with the field).
The book isn't dry either, it's honestly one of the best books I've read in years.
Another one that is also very good is "The Future of Fusion Energy" which has lots on modern methods.
Also well worth checking are the podcasts 'Physical Attraction' which has done many episodes on fusion and 'Omega Tau' that has long episodes on ITER, Wendelstein 7X and superconductors.
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