It is our intent to become a major player in the field of Thermoelectric POWER GENERATION using the SEEBECK EFFECT. Incredible interest is building in this novel field. Estimates are that thermoelectric POWER technology will become more competitive than solar or wind technologies even with these technologies having a head start as far as deployment and technological advances. The pay back on thermoelectric power/watt is more economical presently, than both wind and solar, even with the smaller efficiencies that presently are available with today’s materials. (Based on large project deployment) The quoted cost recently at a Department Of Energy funded workshop Sept. 30/2009 was 50 cents per watt based on a Delta Temperature (DT) of 100°C exempt of assembly materials and installation when large volume pricing is used.
The draw back to the TEG POWER technology is also it’s strength. Because the power densities are very large, small units can be manufactured. For example a 300 watt TEG assembly can fit in an about a twentieth of the space required for an equivalent solar array. As well, the output is 24 hours per day as long as there is a heat source and a cold removal side. So, actual power output could be 6 -7 times what a 300 watt solar array could produce. What is needed to make the technology cheap to operate is waste heat, which by the definition is free. The key words being “WASTE HEAT”. To extract the most efficiency and thermoelectric power from the present state of the art semiconductor materials. It is advisable to have a temperature of 150 to 250°C (302-482°F) hot side, with a Delta Temperature (DT) of at least 100°C. Some applications can work on low grade heat in the 100°C (212°F) range, if the volume of waste heat is high and ample cold side water or air is available. Presently, Bi2Te3 is the most efficient at room temperature. Material such as PbTe, and CMO’s have also been used in temperatures of 350 to 600° C (702-1112°F). Both Bi2Te3 and PbTe are mature material.Their characteristics and performance are well documented and have been used extensively in commercial application. PbTe however, is almost impossible to purchase commercially by itself in module form until now. Starting June 1st, 2014 PbTe will be offered as a Hybrid Thermoelectric module combining the best in class BiTe P-type with the best in Class PbTe N-Type material to form the first Hybrid TEG modules classed as a TEG1-PB series module. PbTe properties are better suited to temperatures above 300°C so the combination works well in the 300°C to 360°C range. We also carry CMO’s which work at very high temperatures 500°C to 800°C and come in both single module construction and also Cascaded (stacked) with Bi2Te3 on the cold side to take advantage of lower temperatures ranges after the higher heat has passed through the CMO material. These Cascades result in an overall efficiency of ~6 to 7 %.
Therefore, Starting in June 2014 we will offer four classes of thermoelectric modules:
-Bi2Te3(Bismuth Tellurium) SERIES 1. Up To 320°C
-PbTe-BiTe (Lead Tellurium/Bismuth Tellurium) HYBRID SERIES 1 PB. Up to 360°C
-Calcium Manganese Hot side with Bismuth Tellurium cold side) CMO CASCADE. Up to 600°C
-Calcium Manganese Oxide CMO. Up to 800°C
There are other Thermoelectric TEG power materials using the SEEBECK EFFECT that hold promise in the thermoelectric generation field. These include but not limited to:
- Mg2Si –N-type
- Mn2Si –P-type
- ZnSb — N-type
- ZnSb –P-type
- Half Heusler –N-Type
The seven Thermoelectric power materials above are of particular interest as they are fairly abundant materials and less expensive compared to Te (Telluride) based semiconductors and have equal or Greater SEEBECK EFFECT Traits . An additional major factor is toxicity. The material above in RED signify benign or exhibit little or no toxicity. Some of these materials can be discussed on thermoelectric TEG module BLOGS located on the instructables wed site.
A typical product that most people are familiar with that using the BiTe material is the Ecofan. This generator sits on top of a wood burning stove and turns a simple fan using the different temperature (DT) between the wood stove tops temperature and the cooling fins on the top of the aluminum assembly. The thermoelectric module is sandwiched in between the hot side and finned cold side.