[aerohead]

The steam provided to the turbine must be exceptionally clean and dry, in order to not erode the super-expensive turbine blades.
Seems like it would have to be in its own closed-loop, as in any thermal-powered power plant, traveling to and from the heat source via a heat-exchanger, or the hot well working fluid traveling from the bore-hole to and from the heat-exchanger.
Carson City, Nevada sits atop a super-volcano caldera, and they tap this as a source of 'shallow' heat.
Seems like these 'shallow', thin lithosphere locations, close to the magma, would be the 1st-choice locations. They'd require the minimum drilling and completion costs, plus get into service the quickest, all else being equal.