Futurology

I think the biggest issues is access to heat and permeability of the rock containing the heat. According to Google the earth's temp rises by 25°C for every km down, so you'd probably want to go at least 4 km down to get enough heat to boil water (in my experience, it isn't 25 degrees hotter 1km down, but you get the idea. ) your also need to consider the pressure of the water and the heat you might lose as you lose pressure coming back up.

You also need to create a circuit where you pump cool water in one end and hot the other. So you can frack the rock like in a gas well, but that can cause seismicity and affect the local hydrogeology which other industries and the towns may rely on. This would enable the water to pass through the rock to soak up the heat.

I guess you'd also need a supply of water as you'd doubtless lose some water as it passes through the circuit, though I'm not sure what the retention losses are actually like and would depend heavily on the local geology