Electric energy from thermocouples

In summary, a thermoelectric generator can be created by connecting millions of contacts or "spots" on a long wire in series or parallel and making half of them warmer than the other half. However, it is known to be an inefficient heat engine with limited practical applications due to the limitations of thermal and electrical conductivity in the materials used. It may have potential for small energy needs, but is not cost effective in most cases.
  • #1
Brainiac
6
0
If I were to make millions of contacts or "spots" on a long wire,and connect them in series(or parallel?),then make half of them warmer than the other half,would I get any useful voltage,i.e. electrical energy I could use to power something?
 
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  • #2
Yes, this is known as a thermoelectric generator. They are rather inefficient heat engines, but they do have some practical applications.
 
  • #3
I always make allowances for the inclusion of thermionic converters in appropriate circumstances for things that I design. For instance, wrapping the hottest parts of an automotive exhaust system in a blanket of them can provide enough juice to run your radio and GPS at least, and perhaps more. It really wouldn't be cost effective, but it might save a small fraction of a mpg via decreased electromagnetic drag upon your alternator.
It's a fun exercise, but not worth doing in reality.
 
  • #4
DaleSpam said:
Yes, this is known as a thermoelectric generator. They are rather inefficient heat engines, but they do have some practical applications.

But why is it inefficient? Also one little question: would I need to connect them in series or parallel?
 
  • #5
Brainiac said:
would I need to connect them in series or parallel?
That depends upon whether you require more voltage or more current.
 

1. What is a thermocouple?

A thermocouple is a device that converts thermal energy into electrical energy. It consists of two dissimilar conductors joined at one end, known as the hot junction, and connected to a measuring instrument at the other end, known as the cold junction. The temperature difference between the two junctions creates a voltage that can be measured and used as a source of electric energy.

2. How does a thermocouple generate electric energy?

A thermocouple generates electric energy through the Seebeck effect, which is the conversion of heat energy into electric energy at the junction of two different conductors. When there is a temperature difference between the two junctions of a thermocouple, it creates a voltage that is proportional to the temperature difference. This voltage can then be used to power devices or charge batteries.

3. What types of materials are used to make thermocouples?

Thermocouples are typically made from two different types of metals, such as copper and constantan, or iron and constantan. These metals are chosen because they have different thermal conductivities and create a higher voltage when they are connected at the hot junction. Other materials, such as semiconductors, can also be used to make thermocouples.

4. What are the advantages of using thermocouples for electric energy?

One of the main advantages of using thermocouples for electric energy is their ability to generate electricity without the need for any moving parts or external energy sources. They are also highly durable and can withstand high temperatures, making them suitable for use in harsh environments. Additionally, thermocouples have a fast response time and can accurately measure temperature differences, making them useful for a variety of applications.

5. What are the limitations of using thermocouples for electric energy?

One limitation of using thermocouples for electric energy is that they have a low energy conversion efficiency. This means that a large temperature difference is required in order to generate a significant amount of electric energy. Thermocouples also have a limited temperature range and may not be suitable for applications that require very high or low temperatures. Additionally, they can be affected by external factors such as electromagnetic interference, which can affect their accuracy.

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