[dredmorbius]

More generally: combustion, though there might be other options.

Boiling water, internal combustion (turbines or reciprocating engines), or external combustion (heating a boiler, and using the steam to drive turbines), would cover most of it. There might be some more exotic options of fuel cells, but those tend to be cost-prohibitive.

All combustion processes follow Carnot's laws, which limit fundamental efficiency.