Can Geothermal Drilling Make A Volcano Erupt?
Geothermal plants drill hundreds of m into the ground to harvest heat produced by magma. But is drilling in volcanic areas not risky business?
The utilisation of Earth’s heat as an energy source requires drilling into Earth’s crust – often in volcanic areas, where red-hot magma is located close to the surface. Although it may sound risky, the drilling has absolutely no effect on volcanic activity.
One reason is that engineers deliberately never drill too close to a magma chamber. They are interested in the warm water located at a safe distance from the molten rock. The water is extracted from the ground to release its energy on the surface either as district heating in homes or by powering a turbine which generates electricity.
Another important reason is that the quantity of thermal energy in the magma is much larger than the energy that geothermal plants potentially need to harvest. According to experts, 47 terawatts are flowing out through Earth’s crust – partly deriving from the original heat in Earth’s interior, partly from the decay of radioactive elements such as uranium, radium, thorium, and potassium. Today, only 0.009 terawatts are utilised via geothermal methods globally. According to geologists, the relatively small quantity of energy utilized has no effect on volcanic activity. The switch-over to thermal energy is well under way in several places – such as Iceland, south-western USA, the Philippines, Mexico, and Italy. Common to those places is that the temperature in Earth’s crust rises very quickly with depth, so the energy is basically easy to obtain.