`If your nuclear reactor produces steam then it's already basically useless in terms of power generation as it will cost more to run the steam turbine alone than to build renewables of the same capacity.`

Can you provide _any_ source for this?! You're saying geothermal and hydro (w/o the environmental issues) aren't competitive with other renewals? They turn turbines as well.

Geothermal isn't competitive with PV and Wind. Neither is coal or nuclear. (Hydro can be used as storage so it's a bit more complicated, but still basically not competitive)

See any recent Lazard's Levelized Cost of Energy Analysis for full details.

For my specific claim about the cost of running just the steam part, look for the golden diamonds on the first chart here:

https://www.lazard.com/perspective/levelized-cost-of-energy-...

They mark the marginal cost of running a fully depreciated nuclear, coal or gas plant. Note how you can build new wind and PV for the same price as running the existing turbine based plants.

Those costs still include fuel, but don't include building the structures. So magical, fuel-less heat source powering steam is still going to struggle as PV and wind continue to drop in price.

Geothermal steam turbines cost more to build and operate, but may operate (mainly) at times when solar and wind don't. Hydro turbines are much cheaper to maintain than steam turbines, although dams are expensive to build. Both compete with turbines driven by NG, likewise operated mostly when the much cheaper solar and wind are not producing enough. As storage is built out, demand for geo and NG declines. Their marginal cost grows as the fraction of time they spend idle increases, because their turbine maintenance cost is not strongly dependent on actual usage.