In an age of dwindling natural resources, energy-saving is the order of the day. However, many technical processes use less than one-third of the energy they employ. This is particularly true of automobiles, where two-thirds of the fuel is emitted unused in the form of heat.
About 30 percent is lost through the engine block, and a further 30 to 35 percent as exhaust fumes. Scientists all over the world are developing ways of harnessing the unused waste heat from cars, machines and power stations, in order to lower their fuel consumption.
There is clearly a great need for thermoelectric generators, or TEGs for short. These devices convert heat into electrical energy by making use of a temperature gradient. The greater the temperature difference, the more current TEGs can produce. Researchers at the Fraunhofer Institute for Physical Measurement Techniques IPM are developing thermoelectric materials, modules and systems to harness the residual heat in automobiles.
“The temperatures in the exhaust pipe can reach 700 degrees Celsius or more,” says Dr. Harald Böttner, head of the Thermoelectric Systems department. “The temperature difference between the exhaust pipe and a pipe carrying engine cooling fluid can thus be several hundred degrees Celsius.” The thermoelectric converter makes use of this huge differential: Driven by the flow of heat between the hot exhaust fumes and the cold side of a coolant pipe, the charge carriers pass through special semiconductors, thus producing an electric current similar to a batterie.
The long-term objective is to make the alternator superfluous and to supply energy to the constantly rising number of power consumers in the car. TEGs could cover a significant proportion of a car’s power requirements: “This would make it possible to cut gas consumption by between five and seven percent,” says Böttner.
A simple calculation will illustrate how important it is to increase the energy efficiency of cars: There are about 50 million licensed motor vehicles in Germany, each of which is – as a basis for an estimation – on the road for an average of 200 hours a year.
If their waste heat was utilized by TEGs during that time, with an output of one kilowatt sufficient to power parts of vehicle electronics, this would add up to ten terawatt hours of energy per annum – a significant contribution. The researchers are still in the experimentation phase at present, but they plan to build the first prototypes very soon.
Press Office | alfa
Generating needs-led electricity with biogas plants
17.10.2018 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Ultra-light gloves let users 'touch' virtual objects
16.10.2018 | Ecole Polytechnique Fédérale de Lausanne
Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.
Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
17.10.2018 | Event News
16.10.2018 | Event News
02.10.2018 | Event News
17.10.2018 | Trade Fair News
17.10.2018 | Life Sciences
17.10.2018 | Agricultural and Forestry Science