How do you convert thermal energy to electrical energy?

Thermal energy is at the root of how electrical energy is made. Steam, which is a form of thermal energy, is used to drive a turbine. That turbine drives a generator (mechanical energy), which produces electrical energy. When you plug your toaster into the wall, it is drawing electrical energy from the wires in your house and strung along poles out on the street. Those wires run back through transformers and along many other wires to a power generation plant, where thermal energy (either coal-fired or solar thermal) is used to create electricity.

Thermal energy is not always used to create electrical energy. Wind and hydroelectric power systems are a couple exceptions, where mechanical energy in wind and water is harnessed to drive a generator. But even solar photovoltaic (PV) panels, which are considered separate from solar thermal systems, utilize solar radiation (a vehicle for thermal energy) to excite electrons in a semiconductor and create electric current.