Heat flux from inside the Earth is limited by the surface area of the Earth. Adding a geothermal plant essentially increases the available surface area, which w

Heat flux from inside the Earth is limited by the surface area of the Earth. Adding a geothermal plant essentially increases the available surface area, which would increase the flux. However, it would be a very small increase to a very small source of heat. Underground heat in total is only about 0.03% of total energy budget at the surface.