It's true that:

* Geothermal power plants rely on heat from the Earth's interior. This heat is usually found in areas where hot rocks are relatively close to the surface.

* These hot rocks are often found near active volcanic areas or tectonic plate boundaries. These areas have a higher heat flow from the Earth's mantle.

However, it's not true that geothermal plants can only be built in these places. While these areas offer the most concentrated and accessible geothermal resources, there are other ways to access geothermal energy:

* Enhanced Geothermal Systems (EGS): These systems involve drilling deeper into the Earth and injecting water to create artificial reservoirs for extracting heat. This allows access to geothermal energy in areas without naturally occurring hot water.

* Geothermal heat pumps: These systems can utilize shallower geothermal resources, even in areas with cooler temperatures. They extract heat from the ground even at depths of just a few meters.

So, while geothermal plants are more commonly built in areas with naturally occurring hot water, they are not limited to these locations. The development of EGS technology and geothermal heat pumps expands the potential for geothermal energy production.

In summary:

* Geothermal plants are often located near volcanic areas or plate boundaries due to the availability of hot rocks.

* EGS and geothermal heat pumps allow access to geothermal resources in areas without naturally occurring hot water.

Therefore, geothermal energy has the potential to be a valuable source of renewable energy in a wider range of locations than just those with easily accessible hot rocks.