A solar thermoelectric generator (STEG) is disclosed. A STEG includes a thermoelectric generator (TEG) configured to convert light energy from solar light into electrical energy, and a heat transfer structure coupled to the TEG where a portion of the heat transfer structure is configured to be embedded in the earth. The TEG includes a first side and a second side, wherein the solar light is incident on the first side of the TEG and the heat transfer structure is configured to provide cooling for the second side of the TEG using geothermal cooling. The use of geothermal cooling to provide cooling for the second side of the TEG increases the temperature difference across the TEG of the STEG, thereby increasing the net generation efficiency of the STEG.