Forecasting Fusion Power

IMO it's not really a book review, it's a well-written and data-driven argument that commercial fusion power is about 10-15 years away, no really for real this time.

It doesn't say that. It says that (he thinks) they'll get Q>5 in research reactors in 10 to 15 years.

Then they can start doing all the research to figure out the systems surrounding the core reactor.

Then they can do actual engineering on systems that produce commercial power. Probably a lot of that commercialization engineering will require further experimental tests, since there's so much new stuff involved.

Then they can get the permits and build them.

If the most optimistic predictions in that review came true right on schedule, you might have actual commercial fusion up and putting power into the grid in 30 years.

As someone who works in this field, let me add some thoughts:

• Marvel is a joke. I put it at less than 10% that they would even beat the NIF record by 2035.
• ITER is planned to turn on by 2025, but by now that is late 2025 ("turn on" means "create a plasma that is no more interesting than that in a fluorescent lamp"). From inside channels I know they plan to announce further delays later this year. Even if everything goes according to the present schedule, actual deuterium-tritium operation is planned to start in 2035. They will ramp thing up carefully, there will be no q=10 success on the first try.
• Even now, the design of crucial parts of the ITER heating system is not finished.
• The design of CFETR is not finished, it is not intended to be a commercial power plant (more of a post-ITER experiment), and the Chinese institute of plasma physics plans to build an intermediate tokamak, called BEST (I kid you not), before they start building CFETR.
• Don't confuse Tokamak Energy with the Culham Centre for Fusion Energy, the location of the Joint European Torus. Tokamak Energy merely rents some office space there (possibly in a deliberate ploy to leech credibility?). The successes of JET are not Tokamak Energy's.

Update: Commonwealth Fusion Systems is the Same Scale as OpenAI (aiimpacts.org)

Seems like CFS (which is responsible for SPARC) is now aiming for 2025? So basically things are on track maybe?

I have a question about tritium breeding. How many free neutrons does D-T fusion produce? According to Wikipedia it is only one. Assuming less than 100% efficiency, this means we produce less than one tritium nucleus per reaction, meaning than we are losing tritium overall. How can we make up the shortfall?