Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MIT revamps energy system for more fuel-efficient cars

23.05.2006
MIT researchers are trying to unleash the promise of an old idea by converting light into electricity more efficiently than ever before.

The research is applying new materials, new technologies and new ideas to radically improve an old concept -- thermophotovoltaic (TPV) conversion of light into electricity. Rather than using the engine to turn a generator or alternator in a car, for example, the new TPV system would burn a little fuel to create super-bright light. Efficient photo diodes (which are similar to solar cells) would then harvest the energy and send the electricity off to run the various lighting, electrical and electronic systems in the car.

Such a light-based system would not replace the car’s engine. Instead it would supply enough electricity to run subsystems, consuming far less fuel than is needed to keep a heavy, multi-cylinder engine running, even at low speed. Also, the TPV system would have no moving parts; no cams, no bearings, no spinning shafts, so no energy would be spent just to keep an engine turning over, even at idle.

"What’s new here is the opportunity for a much more effective energy system to be created using new semiconductor materials and the science of photonics," said Professor John Kassakian, director of the Laboratory for Electromagnetic and Electronic Systems (LEES), where the work was conducted. The idea is to create intense light, let it shine on new types of photo diodes to make electricity, and bounce any excess light back to the light source to help keep it glowing-hot. In theory, Kassakian said, efficiency could be as high as 40 percent or 50 percent.

Kassakian is a professor in the Department of Electrical Engineering and Computer Science (EECS). His research colleagues are EECS Professor David Perreault and LEES principal research engineer Thomas Keim, plus EECS graduate students Ivan Celanovic and Natalija Jovanovic.

At the heart of their energy system would be a cylindrical element, such as tungsten, etched with tiny pits -- nano-holes -- so it emits intense light at selected wavelengths when heated to a high temperature, perhaps 2,200 degrees Fahrenheit (1,500 Kelvin). Special light-sensing cells, made of a new material such as gallium-antimonide, would surround the glowing element, picking up the radiated light. A highly specialized filter, set between the two, would let the most useful light wavelengths pass through to hit the photo diodes, while reflecting light of less useful wavelengths back to the heating element, pumping up the temperature.

The relatively high efficiency, compared to photovoltaic systems in use today, is expected to come from scientists’ new ability to fine-tune all three main parts of this system. This includes the light emitter, the cells that respond well to that tuned light, and a way to scavenge light at wavelengths that might otherwise be wasted.

"This new technology is what makes it a very attractive system," Kassakian said. "There are the new materials that let us build more appropriate photo diodes" that convert light into electricity. "There’s our new understanding of photonics that lets us build the selective emitters" to glow brightly at specific wavelengths. "And there’s the photonic band-gap filter, made of thin silicon and silicon-dioxide layers that act as selective mirrors, letting the desired wavelengths through and reflecting back the rest."

Of course, numerous engineering problems remain to be solved. Kassakian said the light-collecting cells will have to be cooled: "We’ll want to run as hot as we can, but not melt everything." Also, different materials are being tested to see which work best in terms of light emissions, light harvesting and light reflection.

"This whole concept is simple and not new," he added. Back in the late 1960s and early 1970s, much research was done on TPV and light-harvesting technology, first to create solar energy systems for spacecraft, and then in response to energy shortages that spurred an intense burst of research into various alternative energy technologies, he said.

The first focus of this MIT research "is for an automotive system that will take excess heat from the TPV system and use it to drive the car’s heating and air conditioning systems," Kassakian said. "And what this would do is replace the present alternator and air conditioner, both of which are now run by the engine."

In addition, new TPV systems might mesh nicely with hybrid automobile technology, in which fuel is saved by shutting down the engine when the car is stopped, say at traffic signals. In the future, conventional cars may operate the same way. Providing electricity and air conditioning with the engine off will be a necessity.

He added that such a system, once commercialized, might also be applied to other problems, such as supplying the power to run large semi trucks’ lighting, air conditioning and electronic systems, eliminating the need to run the diesel engine all night long while the driver rests. TPV-generated power might also be ideal for uses in remote places, distant from power lines, similar to what is being done now with solar collectors and fuel cells.

Recent papers on this work have appeared in Physical Review B and the Journal of Applied Physics. Initial funding for the research was from the MIT/Industry Consortium on Advanced Automotive Electrical/Electronic Components and Systems.

The work is presently funded in part by Toyota, but Toyota has made no decision to develop this technology for automobiles.

Elizabeth A. Thomson | MIT News Office
Further information:
http://www.mit.edu

More articles from Automotive Engineering:

nachricht 3D scans for the automotive industry
16.01.2017 | Julius-Maximilians-Universität Würzburg

nachricht Improvement of the operating range and increasing of the reliability of integrated circuits
09.11.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH

All articles from Automotive Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Big data approach to predict protein structure

27.03.2017 | Life Sciences

Parallel computation provides deeper insight into brain function

27.03.2017 | Life Sciences

Weather extremes: Humans likely influence giant airstreams

27.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>