Geothermal energy originates from deep within the earth’s crust in geological terrains that have experienced relatively recent magmatic and volcanic activity. Generally high-temperature geothermal fields are located at tectonic plate boundaries where either one plate is being forced over/under another (Pacific Ring of Fire) or where two plates are drifting apart and the geothermal gradient is much higher (Africa Rift System). In both of these cases, the crust of the earth is thinner than normal and often more fractured. This allows for the earth’s heat to superheat ground water forming geothermal fields. Deep wells (1-5 kilometres) are drilled to access these heated fluids which are in turn used to generate electricity before being reinjected back into the ground (see Figure).