Creating the E-STOVE

What is a thermoelectric module? Thermoelectric modules are solid-state integrated circuits that employ three established thermoelectric effects known as the Peltier, Seebeck and Thomson effects. It is the Seebeck effect that is responsible for electrical power generation and thus the foundation of our business. You can Google Peltier, and Thomson effect to learn more about those fascinating discoveries! How are thermoelectric modules made? Their construction consists of pairs of p-type and n-type semiconductor materials with a high thermoelectric coefficient. Although many different materials can be used a bismuth telluride alloy is the most common material in use today. This material is sliced into small blocks, one forms the p-type conductor and the other the n-type conductor. Each pair forms a thermoelectric couple (TEC). These thermocouples are most often connected electrically forming an array of multiple thermocouples (thermopile). One exception for example would be the temperature sensor inside of an oven or furnace, which usually consist of only one thermoelectric couple.

Most others use many thermoelectric couples that are sandwiched between two pieces of non-electrically conductive materials. It is also necessary for this material to be thermally conductive to ensure a good heat transfer, usually two thin ceramic wafers are used. This now forms what is called a thermoelectric module.

Each module can contain dozens of pairs of thermoelectric couples. These modules are called thermoelectric modules, TEC modules and sometimes Peltier or, Seebeck modules, which simply denotes whether they are being used to generate electricity (Seebeck) or produce heat or cold (Peltier). Functionally there is no difference between the two. They both are capable of producing heat and cold or generating electricity, depending on whether heat is applied or an electrical current.

There are however differences in performance between various modules depending on what they were manufactured for! For example, if a module is being manufactured for use in a 12 volt dc automotive cooler the thermoelectric couples will be of a thicker gage and so will the wire connecting the modules to the 12 volt dc power source. In most cases the module itself is quite large. This is simply because the module will be conducting a heavy load of currant and will need to be able to handle the load. Although these type modules can be used to produce electricity they are not well suited for the task because they have a high internal resistance (lowering output) and lower temperature solder that may melt if used for Seebeck purposes. Meaning the electrical connection may fail when the higher heat needed to produce significant amounts of electricity is applied to the module.

Now, if a thermoelectric module is being manufactured for use in a thermoelectric generator it has its own unique requirements. First they need to have lowest internal resistance possible and high temperature silver solder connecting the wires. In addition, heat resistant insulation made from PTFE is used to coat the wires. Braided fiberglass sleeves can also be slipped over the wires providing further protection from the high heat.

What is a TEG?

TEG is an acronym for ‘thermoelectric generator’. A TEG is a device utilizing one or more thermoelectric models as the primary component/s, followed by a cooling system that can be either passive or active. Such as an open air heat sink, fan cooled heat sink, or fluid cooled. These components are then fabricated into an assembly to function as one unit called a TEG.

When heat is applied to the hot side of a TEG, electricity is produced. Almost any heat source can be used to generate electricity, such as solar heat, geothermal heat, even body heat! In addition the efficiency of any device or machine that generates heat as a by-product can be drastically improved by recovering the energy lost as heat.

Can you really generate that much electricity from waste heat? You may be surprised just how much you can! Here is a small example of how much power you can generate. Below is a pot of hot water with 4-thermoelectric modules attached around the sides. The output from this simple thermoelectric generator (TEG) is about 8 watt and the light is a 12 volt auto lamp.

Thermoelectric generators have been in use for many years by NASA to power spacecraft and the oil and gas industry to power remote monitoring stations around the globe. Only in recent years has this technology become available to the general public and TEG Power is at the forefront of this thermoelectric energy revolution. We are the first manufacture to provide practical and affordable thermoelectric generators to the energy conscious consumer.

Almost any heat source can be used to generate electricity, such as solar heat, ocean heat, geothermal heat, even body heat!