Alternative Energy

Alternative energy news, and information about renewable energy technologies.

Oct 22

Thermoelectric Materials Can Increase Energy Efficiency

Posted in Energy Inventions | Future Technology

It seems humans are facing the biggest challenge of the century i.e. to solve energy crisis. We are running the risk of exhausting fossil fuel reserves. Scientists all over the world are working hard to solve this problem. Researchers at the University of Arhus, Riso-DTU and the University of Copenhagen are banking heavily on properties of thermoelectric materials, which is of great importance for their practical application. This material turns heat into electricity more efficiently than anything available today.

Thermoelectric materials can be used for the development of new cooling methods. This improvement can arrest the use of greenhouse gas (R-134a). The researchers are optimistic about thermoelectric materials in the group of clathrates, which create crystals full of ‘nano-cages’. Thermal conductivity of the nano-cages can be reduced if a heavy atom is placed inside those cages.

Thermoelectric materials can be used to build up vehicles that are more fuel-efficient and for more environmentally friendly. Thermoelectric materials have some unique properties; these materials can be assembled into units, which can convert the thermal difference into electrical energy or vice versa – electrical current to cooling. For efficient use, the material should supply a high voltage and have good electrical conductivity. But the thermal conductivity of the material should be low. This low thermal conductivity is very important because it will lessen the “electrical” wear and tear of a device. Car manufacturers are finding the thermoelectric materials very attractive for the conversion of wasted heat into electrical energy.

Overall the majority of the heat from vehicles is wasted. Using thermoelectric materials we can turn the wasted heat of various devices such as a car’s exhaust pipe or a power station, into useful power. This material transforms heat into electricity by using the difference in temperature across the different sides of a device. If we attach a thermoelectric device into a car’s exhaust pipe, it can produce electricity which can be used for driving the car or charging a battery.

Nflight

Thermoelectrics

Conversion of heat to electricity has been proven and in working models for many years. Several US companies currently produce materials for producing this unique thermo-chemical reaction. The uses of these devices have always intrigued me. My first experience was to purchase a 12 volt igloo cooler and take it apart. Once I got to the thermoelectric cooler I removed the coating to observe the tiny squares of material arranged in away similar to a checkerboard, fascinating. But, I ruined my igloo cooler but, I learned something. This was 1997.

http://www.floridaplants.com/CR/thermo.htm
http://www.powerchips.gi/technology/overview.shtml

I was intrigued to learn more and delved into many areas of the thermoelectric realm only to learn by making a physical call to one of the manufacturers that the efficiency of the devices was only 1% efficient. I was not very happy in that response.

http://www.technologyreview.com/NanoTech/wtr_15959,303,p1.html?trk=nl

Late in 2007 a discovery of material arranged in miniature form and using nanoscale materials achieved 10% efficiency this is now starting to be closer to a workable item.

http://biopact.com/2007/10/thermoelectric-devices-could-save.html

As of today the envelope of Thermoelectrics is now approaching somewhere near 12% efficiency making the development of the apparatus viable for a return on a profit viable.

http://www.nextremethermal.com/pages/applications/power_generation.html

Manufacturers of the material can be found in these links:

http://www.marlow.com/
http://www.zts.com/
http://www.tetech.com/
http://www.melcor.com/
http://www.thermacore.com/
http://www.zts.com/node/3955

Hope this helps
Nflight

Thermoelectics have been around for many years. Just 10 years ago the maximum efficiency was just 1%, today we are approaching 12%. Anything above 10% is considered an excellent time for implementation. The leading company in the field is http://www.nextreme.com they have developed power from heat directly to electricity at power ratios of >20watts per square centimeter, or >120 watts per square inch. Simply amazing technology with no moving parts to breakdown.
Rick Lanese

It seems like a good concept, but I am still not clear on how Thermoelectric materials actually can increase energy efficiency. Can someone elaborate more on this concept, it will help me better understand the article. Thanks a bunch Rick L.
Shawn

One way that thermoelectric materials can increase energy efficiency is by converting waste heat to electricity. If they can be placed next to a hot surface, the temperature difference will cause electricity to flow. For example, if you placed a thermoelectric device next to your cars muffler, it could generate electricity to help charge your cars battery, decreasing some or all of the work your alternator would do. This would mean your engine would not have to work as hard and you would save energy. All from heat energy that would otherwise be wasted.
Cyril R.

This is interesting work, but for cooling, efficiency will never be as good as an advanced heat pump system (such as transcritical CO2 cycles). There may be some luxury niche applications like seat heaters/coolers.
Nflight

Rick Lanese:
Imagine a Fuel Cell using just Hydrogen and Oxygen as the fuels to make electricity. The total energy efficiency of the Fuel Cell is nearly 50%. The remaining 50% is wasted heat of temperatures approaching 2000°F. Lets say you install the Thermoelectric’s around the perimeter of the Fuel Cell while in operation. Thus converting the wasted Heat into electricity with out any moving parts. The efficiency of the Thermoelectric’s is at 10%, after install your electric production on the Fuel Cell has increased now just 5% more. Thus giving you a 55% efficient Fuel Cell.
That is the beauty of Thermoelectric’s, added efficiency without any moving parts needed!