Abstract: A thermoelectric generator module which is formed with a hot side heat exchanger having extruded fins on one surface and in contact with a series of individual thermoelectric semiconductor modules on the opposite side of the exchanger. A cold side heat exchanger attached to the opposite side of the semiconductor modules from the hot side heat exchanger, producing a thermal gradient across the semiconductor modules. The semiconductor modules are placed in an arranged pattern so that a maximum of heat flow through the modules is produced. Each semiconductor module is connected electrically to each other so that their output may be combined to produce a large quantity of electric power. A series of generator modules may be interconnected in a series or parallel combination to form a thermoelectric generator of varying power output.