1. A server cooling system, comprising:a tank containing an electrically insulating liquid;
one or more servers submerged in the liquid, wherein at least a portion of the heat generated by the one or more servers is transferred to the liquid;
an elongated cooling loop extending vertically between a first end portion and a second end portion, wherein the first end portion is located in the surrounding air and the second end portion is located beneath the surface of the earth; and
a heat exchanger positioned between the tank and the cooling loop configured to transfer heat from the liquid to the cooling loop,
wherein the heat exchanger comprises a thermally conductive wall in contact with the liquid on one side and in contact with the cooling loop on an opposite side.