Why don't we harness the energy of volcanoes?

Answer 1

We do, in a way. It's called geothermal energy, and it involves (basically) placing a pipe into a geothermal hot spot, and then extracting hot water or even steam to heat structures above. The steam can also be used to spin a turbine and generate electricity, which can be used remotely via transmission lines. The heat resources within the earth are massive compared to both what is currently captured, and even compared to what we would need to power everything up.

Answer 2

Harnessing energy from volcanoes is challenging due to the unpredictable nature of volcanic eruptions, difficulty in accessing volcanic areas, and environmental risks associated with extracting energy from such high-risk environments. Additionally, the cost of developing technology to effectively capture volcanic energy may not be feasible compared to other renewable energy sources that are more abundant and reliable.