Not all thermal energy is created equal. The temperature level plays a huge role, and I imagine geothermal is on the low end. Suitable for household heating and

Not all thermal energy is created equal. The temperature level plays a huge role, and I imagine geothermal is on the low end. Suitable for household heating and the like, but not for smelting metal. From hydro, you generate electricity, and that can be converted to thermal energy on very high temperature levels.