Pardon me if I'm talking out of my ass, but this is what I tought:
* The main input to a fusion reactor is electrical power.
* The main output of a fusion reactor is even more power.
So that seems to me to mean that once you've incurred the capital cost, the machine produces free energy. My reasoning sounds naive and simplistic, because I don't know what I'm talking about. But what's wrong with my reasoning?
1. A fusion plant would be extremely expensive to build. The most optimistic estimates are 10x per GW vs. fission. But we really don't know how to build one; nobody has identified a material that would work.
2. It is extremely expensive to operate. The most optimistic estimates are >10x fission. A thousand tons of lithium "blanket" would have to be sifted daily to get a few grams of tritium for the next day's operation. Nobody knows how this could be done.
3. It destroys itself with neutron irradiation in only a few years. At best, major parts of the structure would have to be replaced using robots because of the extreme radiation in the parts being replaced. Similarly, for repairs. Nobody has built such robots, so they are custom one-offs.
The fuel cost of fission is a negligible part of its cost. The fuel cost of a fusion plant would be negligible, assuming enough tritium could be obtained at all. The ITER project expects to run out and does not know where they will get enough for future experimentation.
Pardon me if I'm talking out of my ass, but this is what I tought:
* The main input to a fusion reactor is electrical power.
* The main output of a fusion reactor is even more power.
So that seems to me to mean that once you've incurred the capital cost, the machine produces free energy. My reasoning sounds naive and simplistic, because I don't know what I'm talking about. But what's wrong with my reasoning?