@shavixmir
Well one takeaway is the development of highly efficient thermal to electric converters, now up to 40% efficient, more efficient than steam turbines.
So with that in mind, it may be they don't need to dig so many kilometers down to get the kind of heat they would need for direct thermal conversion to electricity.
The regular Peltier converters are already being used in beach box refrigerators/heaters, you pump in electricity to plus and minus and it heats, reverse it plus now in the minus and Vice Versa, it now becomes a refrigerator.
It also can convert heat directly to electricity but not noticeably efficient.
The newest converters, I think from research at MIT, it converts but at a VERY high temp, like 2000 degrees C or near 4K F.
If they cannot find that high a temp then they are back to the old ways, steam into a turbine which means a lot of mechanical crap to maintain.
The new converters have no moving parts, nothing to fail unless it physically breaks.