Fusion is by no means cheap. To quote myself from a different thread:
Even if/when we get commercially viable fusion, there's no reason why it should be significantly cheaper than energy from nuclear fission – you'll still need extremely complicated, high-precision, high-technology machines, generators, cooling towers, buildings, skilled workers, some amount of regulation, and disposal of nuclear waste. Oh, and if your fusion design is a tokamak, it might easily be more expensive than energy from fission reactors.
If you want electrical energy that's some orders of magnitude cheaper, you'll need a break-through in fundamental physics.
> there's no reason why it should be significantly cheaper than energy
According to Lockheed Martin, compact fusion has the potential to produce (modular?) 10MW reactors about the size of a semi-trailer truck. This reactor size reduction comes with a corresponding cost reduction without depending on new physics.
Lockheed Martin has yet to produce any evidence that they have achieved break-even power under laboratory conditions, not to mention a device that scales to MW levels or delivers cheap energy.
My point wasn't about Lockheed Martin per se. With ICF, MCF, and MTF, and many instances of those classes of fusion machines being constructed and tested globally, there is a path and plan to make nuclear fusion viable in the future. Doesn't matter that the first machine costs billions, the price will come down at each every subsequent iteration, even if it takes 100 years (or the discovery of room-temperature superconductors).
Back in February the Chinese EAST project (only $37 million USD) confined a plasma pulse of 50 million K for 102 seconds. Progress is slow, yes, but my point remains. When fusion is finally viable, we should strive to have an open infrastructure that liberates humanity from growing, harvesting, and distributing food. (Japan is well on the way, FWIW.)
Time and money are two compelling reasons. Another is climate change. Some estimates predict a decrease in certain crop yields (such as maize in South Africa) by up to 30%. OTOH, some crops will thrive with a higher CO2 concentration, while others will not tolerate the heat and coming droughts. Indoor farming eliminates global climate as a factor to growth.
> With ICF, MCF, and MTF, and many instances of those classes of fusion machines being constructed and tested globally, there is a path and plan to make nuclear fusion viable in the future. Doesn't matter that the first machine costs billions, the price will come down at each every subsequent iteration
You could have made the same argument about nuclear fission. Fission energy has been viable for decades, and yet we still don't have free energy. You didn't give any reasons why it would be different for fusion.
By the way, your reasoning is flawed: From your assumption that initial prototypes are expensive (which is valid), and the assumption that subsequent commercial designs will be less expensive (also most likely valid), you conclude that it will eventually be so cheap as to be essentially free (definitely invalid conclusion, with lots and lots of counterexamples).
Fusion is by no means cheap. To quote myself from a different thread:
Even if/when we get commercially viable fusion, there's no reason why it should be significantly cheaper than energy from nuclear fission – you'll still need extremely complicated, high-precision, high-technology machines, generators, cooling towers, buildings, skilled workers, some amount of regulation, and disposal of nuclear waste. Oh, and if your fusion design is a tokamak, it might easily be more expensive than energy from fission reactors.
If you want electrical energy that's some orders of magnitude cheaper, you'll need a break-through in fundamental physics.