The Geothermal Generator is the T4 power generator and requires the Frozen Factory Expansion. The machine is built as a 5wx3hx5d multiblock for 75 blocks total and it needs to be placed in the Cold Caverns and then fed Heat Conducting Pipes in order to reach the Magma Caverns. The amount of energy it creates is increased the deeper the pipes go until it reaches the optimal point at which point it will no longer lay pipes. The amount of power this machine produces is dependent on difficulty. The following power amounts assume that the geothermal has the maximum number of pipes: